Skin tumours surgery

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“Skin tumours surgery” can cover several areas:

Benign lesions - cysts, lipomas, nevi, seborrhoeic keratoses
Skin cancer surgery - basal cell carcinoma, squamous cell carcinoma, melanoma
Operative principles - biopsy choices, excision margins, primary closure, grafts and flaps
Mohs micrographic surgery
Sentinel lymph-node biopsy and nodal surgery
Reconstruction and postoperative care
Complications and follow-up surveillance

Surgical management depends on the exact tumour and its site, size, depth, recurrence risk, and pathology. In practice, diagnosis is confirmed with biopsy when appropriate, then the lesion is excised with tumour-specific margins or treated with Mohs surgery in selected high-risk or anatomically sensitive sites.

Which area would you like in detail: benign lesions, BCC/SCC, melanoma, surgical margins and reconstruction, or an exam-oriented overview?

Explain all

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This is a large surgical topic. Here is the map and a short overview before going into one area at a time:

Assessment and diagnosis
History, full skin and lymph-node examination, dermoscopy, photographic documentation, biopsy selection, histopathology, staging, and multidisciplinary referral.
Benign and premalignant lesions
Excision of epidermoid cysts, lipomas, nevi, and treatment of actinic keratosis, Bowen disease, and keratoacanthoma where indicated.
Basal cell carcinoma (BCC)
Usually managed by surgical excision or Mohs surgery. Risk category and location determine margins and whether margin-controlled surgery is preferred.
Cutaneous squamous cell carcinoma (cSCC)
Requires risk assessment for local recurrence, perineural invasion, and lymph-node spread. Treatment is complete excision, often with wider margins for high-risk disease.
Melanoma
Requires a correctly planned diagnostic excision biopsy, then definitive wide local excision based on Breslow thickness. Some patients need sentinel lymph-node biopsy and staging.
Other malignant skin tumours
Merkel cell carcinoma, dermatofibrosarcoma protuberans, adnexal tumours, and cutaneous sarcomas generally require specialist multidisciplinary care.
Operative techniques and reconstruction
Elliptical excision, curettage, shave procedures, primary closure, skin grafts, local flaps, and Mohs surgery.
Nodal surgery and systemic coordination
Sentinel-node biopsy, therapeutic nodal dissection in selected circumstances, imaging, radiotherapy, and systemic treatment are coordinated with oncology.
Complications, pathology review, and surveillance
Bleeding, infection, wound dehiscence, scar problems, incomplete excision, recurrence, new primary tumours, and structured follow-up.

Core principle: do not remove a suspected melanoma or high-risk skin cancer with an arbitrary casual excision. Biopsy type, orientation, margins, pathology review, and reconstruction should preserve accurate staging and enable definitive clearance. This is educational material, not a substitute for care by a dermatologist, plastic surgeon, or surgical oncologist.

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Which topic should I explain first in full exam-note detail?

“Skin tumours surgery” can cover several areas:

Benign lesions - cysts, lipomas, nevi, seborrhoeic keratoses
Skin cancer surgery - basal cell carcinoma, squamous cell carcinoma, melanoma
Operative principles - biopsy choices, excision margins, primary closure, grafts and flaps
Mohs micrographic surgery
Sentinel lymph-node biopsy and nodal surgery
Reconstruction and postoperative care
Complications and follow-up surveillance

Which area would you like in detail: benign lesions, BCC/SCC, melanoma, surgical margins and reconstruction, or an exam-oriented overview?This is a large surgical topic. Here is the map and a short overview before going into one area at a time:

Assessment and diagnosis
History, full skin and lymph-node examination, dermoscopy, photographic documentation, biopsy selection, histopathology, staging, and multidisciplinary referral.
Benign and premalignant lesions
Excision of epidermoid cysts, lipomas, nevi, and treatment of actinic keratosis, Bowen disease, and keratoacanthoma where indicated.
Basal cell carcinoma (BCC)
Usually managed by surgical excision or Mohs surgery. Risk category and location determine margins and whether margin-controlled surgery is preferred.
Cutaneous squamous cell carcinoma (cSCC)
Requires risk assessment for local recurrence, perineural invasion, and lymph-node spread. Treatment is complete excision, often with wider margins for high-risk disease.
Melanoma
Requires a correctly planned diagnostic excision biopsy, then definitive wide local excision based on Breslow thickness. Some patients need sentinel lymph-node biopsy and staging.
Other malignant skin tumours
Merkel cell carcinoma, dermatofibrosarcoma protuberans, adnexal tumours, and cutaneous sarcomas generally require specialist multidisciplinary care.
Operative techniques and reconstruction
Elliptical excision, curettage, shave procedures, primary closure, skin grafts, local flaps, and Mohs surgery.
Nodal surgery and systemic coordination
Sentinel-node biopsy, therapeutic nodal dissection in selected circumstances, imaging, radiotherapy, and systemic treatment are coordinated with oncology.
Complications, pathology review, and surveillance
Bleeding, infection, wound dehiscence, scar problems, incomplete excision, recurrence, new primary tumours, and structured follow-up.

Benign tumor

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Benign skin tumours: surgical overview

A benign skin tumour is a non-cancerous growth that does not metastasize. Many require no treatment. Surgery is considered when a lesion is painful, repeatedly inflamed or bleeding, growing, functionally troublesome, cosmetically unacceptable, or when the diagnosis is uncertain.

Before removal, any lesion with possible malignancy should be assessed clinically and, where appropriate, sent for histopathology.

1. Preoperative assessment

Assess:

Duration and rate of growth
Pain, itching, discharge, ulceration, trauma, infection, bleeding
Previous excision or recurrence
Personal or family history of skin cancer
Anticoagulant use, diabetes, immunosuppression, allergy, keloid tendency
Lesion site, size, depth, mobility, relation to nerves and vessels
Regional lymph nodes if there is diagnostic concern

Red flags: refer or biopsy rather than treating as simply benign

Recent rapid enlargement
Pigment change, asymmetry, irregular border, multiple colours
Persistent ulceration or spontaneous bleeding
Induration, fixation, nerve symptoms
Recurrent lesion after adequate excision
A deep, firm, enlarging soft-tissue mass

A pigmented lesion suspicious for melanoma should not be treated with shave removal, cautery, or cryotherapy because this can prevent accurate diagnosis and staging.

Common benign lesions and their surgery

Lesion	Typical clinical features	Usual management
Epidermoid cyst	Slow-growing, firm mobile dermal nodule, often with a central punctum	Observe if asymptomatic. Definitive treatment is complete excision of cyst and wall
Pilar cyst	Smooth scalp nodule, usually no punctum	Excision, often easily delivered through a small incision
Lipoma	Soft, lobulated, mobile subcutaneous mass	Reassure or excise if painful, enlarging, symptomatic, or uncertain diagnosis
Melanocytic nevus (mole)	Symmetrical stable pigmented papule or macule	Observation if clinically typical. Excisional biopsy if changing or suspicious; cosmetic excision can be considered
Skin tag	Soft, pedunculated lesion in flexures	Snip excision, electrosurgery, or cryotherapy if symptomatic
Dermatofibroma	Firm papule, commonly legs, often dimples on pinching	Usually observe. Excision only if symptomatic or diagnosis is uncertain
Seborrhoeic keratosis	“Stuck-on,” waxy, pigmented plaque	Curettage, shave removal, or cryotherapy if irritated or diagnosis unclear
Pyogenic granuloma	Rapidly growing red friable nodule that bleeds easily	Curettage or shave excision with destruction of the base; send tissue for pathology
Neurofibroma	Soft papule or nodule, sometimes multiple	Observation or excision for symptoms, function, or cosmetic reasons
Hemangioma / vascular lesion	Red-blue vascular lesion	Observation, laser, sclerotherapy, or selected excision depending on type and location

2. Epidermoid cyst

Often called a “sebaceous cyst,” although most are actually epidermoid cysts containing keratin.

Indications for excision

Recurrent inflammation or infection
Pain, pressure symptoms, foul discharge
Repeated rupture
Cosmetic concern
Uncertain diagnosis

Surgical principle

The key is complete removal of the cyst wall/capsule. If a part of the lining remains, the cyst may recur.

Technique, in principle

Local anaesthesia.
Elliptical or small incision, including the punctum or any scar tethered to the cyst.
Gentle dissection and removal of the cyst intact where possible.
Haemostasis, irrigation if needed, and closure.
Send specimen for histology if atypical, recurrent, solid, ulcerated, or clinically uncertain.

Infected or inflamed cyst

A fluctuant abscess may require incision and drainage.
Antibiotics are considered when there is surrounding cellulitis or systemic infection, not for every inflamed cyst.
Delayed definitive excision is often easier once acute inflammation has settled.

3. Lipoma

A lipoma is a benign tumour of mature fat cells. It is usually soft, mobile, painless, and located on the trunk, shoulder, neck, or proximal limbs.

When to investigate or refer

Ultrasound or specialist assessment is appropriate if the mass is:

Deep to fascia
Firm or fixed
Rapidly enlarging
Painful without a clear reason
Recurrent after removal
Large, especially more than about 5 cm
Associated with neurologic symptoms

Deep lipomas may require MRI to define relation to muscles, nerves, or vessels. Surgical excision is generally curative for typical superficial lipomas; recurrence after a properly removed ordinary lipoma is uncommon. Fitzpatrick’s Dermatology, Vols 1-2, “Lipoma” section.

Excision

Incision is placed along skin-tension lines where possible.
The lipoma is dissected out, generally by marginal excision.
The specimen should be sent for pathology when diagnosis is not completely certain.

4. Melanocytic nevus (mole)

Most common acquired moles are benign and need no surgery.

Indications for removal

Suspicion of melanoma
Persistent irritation from shaving or clothing
Recurrent trauma or bleeding
Atypical appearance or documented change
Cosmetic reason after clinical assessment

Important surgical point

For a suspicious pigmented lesion, use an excisional biopsy whenever feasible: remove the whole lesion with a narrow clinical margin and enough depth for histopathological assessment. Do not partially destroy a suspicious lesion.

For clearly benign cosmetic moles, shave removal may leave deeper nevus cells behind and can lead to repigmentation or a recurrent nevus. Complete excision is the more reliable way to remove a nevus fully. Fitzpatrick’s Dermatology, Vols 1-2, “Treatment” section.

5. Dermatofibroma

A dermatofibroma is a benign fibrous dermal lesion, usually a small firm brownish papule on the leg.

Stable, asymptomatic lesions can be left alone.
Excision may be chosen for pain, repeated trauma, diagnostic doubt, or cosmetic concern.
Because it extends into the dermis, full-thickness excision gives better diagnostic tissue and more complete removal than superficial shaving.
Scarring can be more noticeable than the original lesion, so the benefit should be discussed.

6. Pyogenic granuloma

Despite its name, this is not pus-producing and is not a true granuloma. It is a benign vascular proliferation, often after minor trauma, and typically bleeds easily.

Management

Curettage or shave excision
Electrocautery, chemical cautery, or other destruction of the base to reduce bleeding and recurrence
Histopathology is advisable because amelanotic melanoma and other lesions can occasionally resemble it

7. General operative principles

Incision and excision

Plan the scar along relaxed skin-tension lines when possible.
For an elliptical excision, the long axis is usually aligned with these lines to allow primary closure.
Handle tissue gently and achieve careful haemostasis.
Avoid excessive cautery, which can delay healing and worsen scarring.
Close in layers for deeper defects and reduce tension.

Specimen handling

Send a specimen for pathology when:

Diagnosis is uncertain
The lesion is pigmented, ulcerated, firm, recurrent, rapidly growing, or unusual
A malignancy cannot confidently be excluded
The appearance differs from a routine benign lesion

Reconstruction

Small defects usually close primarily. Larger or high-tension defects may require:

Undermining and layered closure
Local skin flap
Full-thickness or split-thickness skin graft
Specialist plastic-surgical reconstruction, especially on the face, eyelid, ear, lip, hand, genitalia, or lower leg

8. Postoperative care and complications

Usual advice

Keep the wound clean and dry according to the clinician’s instructions.
Watch for increasing pain, redness, warmth, swelling, pus, fever, bleeding, or wound separation.
Avoid tension, stretching, and friction at the wound site.
Use sun protection after healing to limit scar pigmentation.

Complications

Bleeding or haematoma
Infection
Wound dehiscence
Hypertrophic scar or keloid
Nerve injury, numbness, altered sensation
Recurrence, especially after incomplete cyst-wall or nevus removal
Unexpected malignant diagnosis on histology

Many common lesions can be treated by excision when needed, including epidermoid cysts and lipomas, but asymptomatic lesions often need only reassurance. The AAFP clinical review notes that excision is commonly used for lipomas, dermatofibromas, epidermoid cysts, and selected other benign lesions.

Key exam point: For benign tumours, surgery is usually elective and symptom-driven. The goals are correct diagnosis, complete removal when indicated, good haemostasis, preservation of function, acceptable cosmesis, and histopathological confirmation whenever there is doubt.

Explain acc to standard book

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Benign tumours of skin - standard textbook style

Definition

Benign skin tumours are localized, non-metastasizing proliferations arising from epidermal, adnexal, melanocytic, fibrous, neural, vascular, or subcutaneous tissues. They are usually slow growing and well circumscribed. Most need reassurance only; treatment is required for symptoms, cosmetic reasons, recurrent trauma/infection, or diagnostic uncertainty.

General principles of management

Confirm the diagnosis clinically, with dermoscopy for pigmented lesions where available.
Do not destroy an uncertain lesion by cautery, cryotherapy, laser, or superficial shaving without obtaining histology.
Send the specimen for histopathology when diagnosis is doubtful, the lesion is recurrent, rapidly enlarging, ulcerated, bleeding, unusually pigmented, fixed, or otherwise suspicious.
Excise completely if removal is indicated.
Plan the incision in a relaxed skin-tension line and use layered closure if the lesion is deep or the closure is under tension.
Suspected melanoma, squamous-cell carcinoma, or other malignancy requires appropriate diagnostic excision or specialist referral, not cosmetic destruction.

Benign lesions generally show symmetry, circumscription, low mitotic activity, and lack of destructive infiltration, unlike malignant tumours. Fitzpatrick’s Dermatology, Vols 1-2, p. 1986.

Classification

A. Epidermal and adnexal lesions

Epidermoid cyst
Pilar or trichilemmal cyst
Seborrhoeic keratosis
Syringoma
Sebaceous hyperplasia
Hidrocystoma

B. Melanocytic lesions

Acquired melanocytic nevus
Congenital melanocytic nevus
Spitz nevus
Blue nevus

C. Fibrous and histiocytic lesions

Dermatofibroma
Keloid
Neurofibroma

D. Adipose and soft-tissue lesions

Lipoma
Angiolipoma

E. Vascular lesions

Cherry angioma
Pyogenic granuloma, also called lobular capillary hemangioma
Hemangioma

F. Other common lesions

Acrochordon or skin tag
Verruca
Xanthelasma

1. Epidermoid cyst

Definition and pathology

An epidermoid cyst is a keratin-filled cyst lined by stratified squamous epithelium. It originates from the follicular infundibulum. It is commonly, but inaccurately, called a “sebaceous cyst.”

Clinical features

Commonest cutaneous cyst
Usually occurs on face, neck, upper trunk, or scrotum
Slow-growing, round, mobile dermal or subcutaneous swelling
Skin-coloured or yellowish
Characteristic central punctum
May discharge foul-smelling, cheesy keratin
Infection or rupture causes pain, erythema, tenderness, and abscess formation

Dermatology 2-Volume Set, 5e, “Epidermoid Cyst” section.

Treatment

Observation if small and asymptomatic.
Definitive treatment: complete excision of the cyst together with its wall.
The punctum and attached scar should be included in the excision.
Incomplete removal of the lining causes recurrence.
Elective excision is best performed when the cyst is not inflamed, that is, in the “cold” stage.
In an abscess, perform incision and drainage. Antibiotics are used when there is surrounding cellulitis or systemic infection. Definitive excision can follow after inflammation settles.

2. Pilar or trichilemmal cyst

Features

Arises from the outer root sheath of the hair follicle.
Commonly occurs on the scalp.
Often multiple and can be familial.
Usually smooth, firm, mobile, and lacks a central punctum.
Contents are more solid and calcification may occur.

Treatment

Surgical excision is curative.
These cysts are often more easily enucleated through a small incision than epidermoid cysts.

3. Lipoma

Definition

A lipoma is a benign mesenchymal neoplasm composed of mature adipocytes. It is the commonest benign soft-tissue tumour in adults.

Clinical features

Soft, doughy, lobulated, and freely mobile subcutaneous swelling
Usually painless
Common on trunk, shoulder, neck, forearm, and thigh
Usually small, but may grow large
Overlying skin is normal

Lipomas are composed of mature white fat cells. Ordinary superficial lipomas are benign, and surgical excision is generally curative. Fitzpatrick’s Dermatology, Vols 1-2, p. 2201.

Differential diagnosis

Epidermoid cyst
Angiolipoma
Neurofibroma
Enlarged lymph node
Soft-tissue sarcoma or atypical lipomatous tumour

Treatment

Observation if typical and asymptomatic.
Excision for pain, pressure symptoms, cosmetic concern, enlargement, or uncertain diagnosis.
A deep, fixed, painful, recurrent, rapidly growing, or large mass should be investigated, often with ultrasonography or MRI, and referred appropriately before excision.
Marginal excision is usually adequate for a typical superficial lipoma.

4. Melanocytic nevus

Definition

A melanocytic nevus is a benign proliferation of melanocytes. It may be junctional, compound, intradermal, congenital, or acquired.

Clinical features

Usually a symmetrical, stable, uniformly coloured macule, papule, or nodule
Colour varies from skin coloured to tan, brown, blue, or black
Acquired nevi usually arise in childhood or early adult life

When to excise

Cosmetic concern
Recurrent trauma or irritation
Recent change in size, colour, surface, or symptoms
Irregular pigmentation or asymmetry
Bleeding or ulceration
Concern for melanoma

Treatment principles

Most common acquired nevi need no treatment. If a lesion is suspicious, it should be excised and examined histologically. Dermoscopy and serial photography help distinguish stable benign lesions from suspicious changing lesions.

Complete removal is best achieved by full surgical excision. Destructive treatment, such as cryotherapy, electrodessication, laser, or dermabrasion, should be avoided for a suspicious nevus because it prevents histological assessment and can leave residual melanocytes with later repigmentation or recurrence. Fitzpatrick’s Dermatology, Vols 1-2, p. 1986.

5. Seborrhoeic keratosis

Features

Benign epidermal proliferation in middle-aged and older people
Waxy, verrucous, sharply demarcated plaque
Classically has a “stuck-on” appearance
May be tan, brown, grey, or black
Usually occurs on trunk, face, and scalp

Treatment

No treatment is required unless irritated, symptomatic, cosmetically unwanted, or diagnostically uncertain.

Methods include:

Cryotherapy with liquid nitrogen
Curettage, with or without cautery
Shave excision

A pigmented lesion suspicious for melanoma should undergo excisional biopsy rather than destructive treatment. Textbook of Family Medicine, 9e, p. 953.

6. Dermatofibroma

Definition and features

Dermatofibroma is a benign fibrohistiocytic proliferation.

Commonly occurs on the legs
Firm, small, brown or reddish-brown papule/nodule
May itch or be tender
Characteristic dimple sign: lateral compression produces central dimpling

Treatment

Reassure if stable and asymptomatic.
Excision is indicated for symptoms, diagnostic doubt, repeated trauma, or cosmetic concern.
Because the lesion is dermal, complete excision is preferable to superficial shaving when removal is needed.
Consider dermatofibrosarcoma protuberans in a large, enlarging, atypical, or recurrent lesion.

7. Pyogenic granuloma

Definition

Pyogenic granuloma is a misnomer. It is a benign vascular lesion, also called lobular capillary hemangioma.

Clinical features

Rapidly growing red, friable papule or pedunculated nodule
Bleeds easily after trivial trauma
Common on fingers, face, oral mucosa, and sites of trauma
May occur in pregnancy on the gingiva, called granuloma gravidarum

Treatment

Shave excision followed by curettage and electrodesiccation of the base
Alternatively, full-thickness surgical excision
Histopathology is important because amelanotic melanoma can resemble a pyogenic granuloma
Residual lesion at the base can lead to recurrence

Textbook of Family Medicine, 9e, p. 953.

8. Acrochordon or skin tag

Features

Soft, pedunculated, skin-coloured fibroepithelial polyp
Occurs in neck, axilla, groin, eyelids, and other flexures
More common in obesity, pregnancy, and insulin resistance

Treatment

None is required. If irritated or cosmetically unwanted:

Snip excision
Electrocautery
Cryotherapy

9. Neurofibroma

Features

Benign peripheral-nerve sheath tumour
Soft, skin-coloured, sessile or pedunculated nodule
May show the “buttonhole” sign, in which it invaginates on pressure
Multiple neurofibromas should raise concern for neurofibromatosis type 1

Treatment

Observation for asymptomatic isolated lesions
Excision for pain, functional impairment, diagnostic uncertainty, or cosmetic reasons
Multiple lesions need assessment for associated genetic syndrome and systemic manifestations.

10. Cherry angioma

Features

Common benign capillary proliferation in adults
Bright red to purple, small dome-shaped papules
Often multiple on the trunk

Treatment

No treatment is necessary. If bleeding or cosmetically troublesome:

Electrocautery
Laser
Shave excision

Short surgical answer: principles of excision of a benign skin tumour

Confirm benign clinical diagnosis and obtain consent.
Mark lesion and incision along relaxed skin-tension lines.
Prepare and infiltrate local anaesthetic.
Make an elliptical incision if complete skin excision is required.
Dissect carefully around the lesion and remove it intact where possible.
Ensure haemostasis.
Send specimen for histopathology where indicated.
Close without tension, usually with deep absorbable sutures and superficial skin sutures if required.
Apply dressing, provide wound-care instructions, and arrange review for histology and suture removal.

Indications for histopathology

Uncertain diagnosis
Pigmented or changing lesion
Ulceration, spontaneous bleeding, or rapid growth
Recurrent lesion
Atypical clinical appearance
Any lesion where malignancy has not been confidently excluded

Exam conclusion: The common benign tumours needing surgery are epidermoid cyst, pilar cyst, lipoma, nevus, dermatofibroma, pyogenic granuloma, seborrhoeic keratosis, skin tag, and neurofibroma. Complete excision is curative for most, but any atypical or suspicious lesion must be submitted for histopathological examination.

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clinical comparison basal cell carcinoma squamous cell carcinoma melanoma skin cancer

This clinical photograph set presents a side-by-side comparison of three distinct types of skin cancer lesions labeled (a), (b), and (c). Image (a) demonstrates malignant melanoma, characterized by an irregularly pigmented, dark brown to black macule situated on a background of sun-damaged, erythematous skin with a rough texture and multiple small papules. Image (b) shows a squamous cell carcinoma (SCC), presenting as a raised, scaly, flesh-colored plaque with an irregular border and central crusting; a clinical ruler is included for scale. Image (c) displays a basal cell carcinoma (BCC), visible as a small, well-circumscribed, pearly erythematous nodule with possible central ulceration. This comparison chart is designed for medical education to assist in the clinical differentiation of primary skin malignancies based on morphology, color, and surface characteristics. Key concepts illustrated include lesion asymmetry, border irregularity, and characteristic tissue changes associated with different histopathological subtypes of skin cancer.

This clinical comparison chart presents eight dermoscopic images of various skin lesions, serving as an educational reference for dermatological classification. Each image represents a category from the ISIC 2019 dataset: Actinic Keratoses and Intraepithelial Carcinoma (AKIEC), Basal Cell Carcinoma (BCC), Benign Keratosis-like Lesions (BKL), Dermatofibroma (DF), Melanoma (MEL), Melanocytic Nevi (NV), Squamous Cell Carcinoma (SCC), and Vascular Lesions (VASC). The visual comparison highlights diagnostic morphological features, including the asymmetrical pigment distribution and irregular borders in MEL and NV, the translucent or pinkish hue with small dark spots in BCC, the central white area characteristic of DF, and the distinct reddish vascular structure in the VASC category. This figure is designed for medical students and clinicians to distinguish between malignant and benign skin tumors based on color variegation, textural patterns, and structural organization. It serves as a visual benchmark for training diagnostic algorithms and improving clinical accuracy in identifying high-level features associated with skin cancer.

This composite figure illustrates the clinical, dermoscopic, and reflectance confocal microscopy (RCM) findings of a basosquamous carcinoma (BSC) on the nose. Image A (Clinical Photograph) shows an erythematous, squamous nodule located on the nasal tip, characterized by a central hyperkeratotic crust and irregular borders. Image B (Dermoscopy) reveals diagnostic features suggestive of both basal cell and squamous cell lineages: a central white-to-yellow keratin mass, focal blood spots, and peripheral arborizing telangiectasia against a whitish structureless background. Image C (RCM) displays the microscopic architecture at the dermo-epidermal junction, showing dark peritumoral clefts and basaloid islands with peripheral palisading, alongside larger polygonal cells representing atypical keratinocytes. This multimodal imaging comparison highlights the overlapping features of BCC and SCC that define BSC, providing high-resolution visual evidence for the diagnosis of this aggressive non-melanoma skin cancer subtype.

Malignant tumours of skin

The main malignant skin tumours are:

Basal cell carcinoma (BCC)
Cutaneous squamous cell carcinoma (cSCC)
Malignant melanoma
Less common tumours: Merkel cell carcinoma, dermatofibrosarcoma protuberans, sebaceous carcinoma, angiosarcoma, cutaneous lymphoma, and Kaposi sarcoma.

Clinical comparison of melanoma, squamous cell carcinoma, and basal cell carcinoma

General surgical principles

Assessment

Take history of:

Duration, enlargement, pain, itch, bleeding, ulceration, or non-healing wound
Sun or ultraviolet exposure, radiotherapy, arsenic exposure, chronic wound/scar
Immunosuppression, especially organ transplant
Previous skin cancer and family history of melanoma
Change in a pigmented lesion

Examine:

Entire skin surface, lesion size, border, pigmentation, ulceration, and fixation
Regional lymph nodes
Cranial nerve function or altered sensation if head/neck SCC is suspected, because pain, paraesthesia, or anaesthesia can indicate perineural invasion.

Diagnosis

Use dermoscopy for suspicious pigmented lesions.
Confirm diagnosis by biopsy and histopathology.
A likely melanoma should usually undergo complete excisional biopsy with a narrow margin, allowing Breslow thickness and ulceration to be assessed.
For a large lesion or a site where total diagnostic excision is impractical, an incisional or punch biopsy should target the thickest or most atypical area.
Do not treat a suspicious lesion with cryotherapy, laser, cautery, or superficial destruction before histological diagnosis.

Definitive surgery

Goals are:

Complete tumour clearance with histologically negative margins.
Preservation of function and acceptable reconstruction.
Accurate staging.
Nodal staging or treatment where appropriate.
Surveillance for local recurrence, nodal disease, and new primary tumours.

Mohs micrographic surgery provides complete peripheral and deep-margin assessment during surgery. It is particularly valuable for recurrent, large, ill-defined, aggressive, or high-risk tumours, and for sites where tissue conservation is important, such as eyelid, nose, ear, lip, digits, and genital skin.

1. Basal cell carcinoma

Definition

BCC is a malignant tumour of basal keratinocytes. It is the commonest human malignancy. It grows slowly and metastasizes only exceptionally, but neglected disease can cause extensive local destruction. Textbook of Family Medicine, 9e, p. 956.

Risk factors

Chronic ultraviolet exposure and fair skin
Increasing age
Immunosuppression
Previous BCC
Ionising radiation or arsenic exposure
Genetic syndromes, for example basal cell nevus syndrome

Clinical types

Nodular BCC: pearly papule or nodule, rolled edge, telangiectasia, possible central ulcer
Superficial BCC: well-defined erythematous scaly patch, often trunk
Pigmented BCC
Morpheaform or infiltrative BCC: scar-like, ill-defined, more aggressive
Basosquamous carcinoma: has aggressive behaviour and requires careful management

A classic lesion is a non-healing, pearly, rolled-edge ulcer or nodule on sun-exposed face, ear, scalp, neck, or upper trunk.

Treatment

Low-risk BCC

Options include:

Standard surgical excision with histological margin assessment
Curettage and electrodesiccation in selected superficial, low-risk lesions
Cryotherapy, topical imiquimod, topical 5-fluorouracil, or photodynamic therapy for selected superficial disease

High-risk BCC

High-risk features include:

Central face, eyelid, nose, lip, ear, genital area, hands, or feet
Recurrent tumour
Large size
Ill-defined border
Aggressive histology, such as infiltrative or morpheaform type
Perineural invasion
Immunosuppression

Mohs surgery is preferred where maximum tissue conservation and complete margin control are needed. Standard excision with adequate margins is an alternative where appropriate.

Advanced disease

Locally advanced or metastatic BCC requires specialist multidisciplinary management. Options can include radiotherapy, hedgehog-pathway inhibitors, or immunotherapy in selected cases. The NCI skin cancer guidance lists excision with margin evaluation and Mohs surgery as standard local treatments.

2. Cutaneous squamous cell carcinoma

Definition

cSCC is a malignant neoplasm of epidermal keratinocytes. Unlike BCC, it can spread to regional lymph nodes and, less often, distantly.

Risk factors

Cumulative ultraviolet exposure
Actinic keratosis and Bowen disease
Fair skin and older age
Immunosuppression, particularly transplant recipients
Chronic wounds, ulcers, burns, sinuses, and scars, called Marjolin ulcer
Ionising radiation, arsenic, HPV in selected anogenital lesions
Chronic inflammation

Clinical features

Hyperkeratotic, scaly, indurated papule, plaque, or nodule
Crusting, ulceration, or bleeding
May be rapidly growing and painful
Occurs mainly on bald scalp, face, neck, dorsal hands, forearms, and legs

Pain, numbness, tingling, or weakness may indicate perineural invasion. Dermatology 2-Volume Set, 5e, “Invasive cutaneous squamous cell carcinoma” section.

Precursor lesions

Actinic keratosis

A rough scaly lesion on sun-damaged skin. It can progress to SCC.

Bowen disease

This is squamous cell carcinoma in situ, confined to the epidermis. Management includes excision, curettage and electrodesiccation, cryotherapy, topical 5-fluorouracil, imiquimod, or photodynamic therapy, depending on site and patient factors. Lesions on digits, penis, recurrent head/neck sites, or ill-defined lesions may require Mohs surgery. Textbook of Family Medicine, 9e, p. 956.

Risk stratification

Features associated with higher local recurrence, nodal metastasis, or death include:

Diameter more than 2 cm
Thickness more than 2 mm or invasion beyond subcutaneous fat
Poor differentiation
Desmoplastic histology
Perineural or lymphovascular invasion
Ear, lip, central face, genital, hand, or foot location
Recurrence
Immunosuppression

Surgical treatment

Low-risk cSCC

Complete surgical excision with histological margin assessment.
Curettage and electrodesiccation may be used only in carefully selected low-risk lesions, not in hair-bearing or high-risk sites.

High-risk cSCC

Mohs micrographic surgery or excision with comprehensive margin control.
Consider imaging if there is concern for deep invasion, bone involvement, named-nerve involvement, or nodal metastasis.
Perform ultrasound-guided needle sampling or biopsy of suspicious regional lymph nodes.

Nodal disease

Confirmed clinically apparent nodal metastasis requires multidisciplinary care. Treatment may include therapeutic lymph-node dissection, radiotherapy, and systemic therapy depending on resectability and disease extent.

3. Malignant melanoma

Definition

Melanoma is a malignant tumour of melanocytes. It accounts for a smaller fraction of skin cancers but causes most skin-cancer mortality because of its capacity for lymphatic and haematogenous spread.

Risk factors

Intermittent intense ultraviolet exposure and severe sunburn
Fair skin, freckles, light eyes/hair
Numerous or atypical nevi
Personal or family history of melanoma
Giant congenital melanocytic nevus
Immunosuppression
Genetic susceptibility

Warning signs: ABCDE

A - Asymmetry
B - Border irregularity
C - Colour variation
D - Diameter, especially enlargement or a lesion larger than 6 mm
E - Evolution, any change in size, shape, colour, surface, bleeding, or symptoms

The “ugly duckling” sign is also important: a mole that looks different from the patient’s other nevi.

Diagnosis

Perform excisional biopsy of the whole suspicious lesion with a narrow margin where feasible. Histology must report:

Breslow thickness
Ulceration
Mitotic activity
Histological subtype
Peripheral and deep margins
Microsatellitosis, if present

Breslow thickness is the most important primary-tumour prognostic measure and guides definitive surgical margin and sentinel-node decisions.

Definitive treatment: wide local excision

After diagnostic biopsy, perform wide local excision of the scar and surrounding skin. Standard surgical margins are based on Breslow thickness:

Melanoma thickness	Recommended clinical excision margin
Melanoma in situ	0.5 cm
Less than or equal to 1 mm	1 cm
More than 1 to 2 mm	1 to 2 cm
More than 2 mm	2 cm

Sabiston Textbook of Surgery, “Wide Local Excision” section.

The purpose of wide local excision is local control by removing microscopic residual disease around the original melanoma. Fitzpatrick’s Dermatology, Vols 1-2, “Surgical Treatment of Primary Melanoma” section.

Sentinel lymph-node biopsy

Sentinel lymph-node biopsy is a staging procedure, not a substitute for wide local excision.

It should be:

Discussed for clinically node-negative melanomas 0.8 to 1.0 mm thick with adverse factors
Recommended or strongly considered for clinically node-negative melanomas more than 1 mm thick

Mulholland and Greenfield’s Surgery, 7e, “Skin and Soft Tissue” section.

A positive sentinel node changes prognosis and guides staging, imaging, and consideration of adjuvant systemic therapy. Routine completion lymph-node dissection after a positive sentinel node is no longer automatic and is individualized.

Advanced melanoma

Resectable local, in-transit, nodal, or oligometastatic disease may be surgically managed in selected patients. Unresectable or metastatic melanoma is managed in a specialist multidisciplinary team with immunotherapy, targeted treatment when actionable mutations are present, radiotherapy, and selected surgery.

The current NCI melanoma summary gives stage-based management and emphasizes the role of accurate pathological staging.

4. Merkel cell carcinoma

Features

Merkel cell carcinoma is an uncommon but aggressive neuroendocrine skin cancer. It often presents as a rapidly growing, painless, firm red-violet nodule on sun-exposed skin in older or immunosuppressed patients.

Management

Wide local excision or margin-controlled surgery
Sentinel lymph-node biopsy is generally recommended for clinically node-negative disease
Adjuvant radiotherapy is frequently used because of high local and regional recurrence risk
Immunotherapy is important for advanced or metastatic disease

Adjuvant locoregional radiotherapy is generally recommended except in a very low-risk, carefully selected group with small primary tumour, negative margins, negative sentinel-node biopsy, absence of lymphovascular invasion, and normal immune status. Dermatology 2-Volume Set, 5e, “Merkel Cell Carcinoma” section.

5. Other malignant skin tumours

Dermatofibrosarcoma protuberans

Slow-growing, locally aggressive dermal sarcoma
Often on trunk or proximal limbs
Needs wide excision with clear margins or Mohs surgery
Local recurrence is a concern

Sebaceous carcinoma

Often arises in eyelid meibomian glands but can occur elsewhere
May mimic recurrent chalazion or chronic blepharoconjunctivitis
Requires complete excision with margin control and specialist assessment

Angiosarcoma

Aggressive vascular malignancy, often on scalp or face of elderly people
Requires multidisciplinary management with surgery where possible, radiotherapy, and systemic therapy

Cutaneous lymphoma and Kaposi sarcoma

Management is usually nonsurgical and depends on disease subtype and systemic involvement.

Follow-up and prevention

After a malignant skin tumour, advise:

Lifelong skin self-examination
Prompt review of any new, changing, bleeding, ulcerated, or non-healing lesion
Sun-protective clothing, shade, and broad-spectrum sunscreen
Examination of regional lymph nodes where relevant
Regular clinical follow-up based on tumour type, stage, recurrence risk, and immunosuppression status

Exam summary

BCC: locally destructive, metastasis is rare. Treat mainly by excision or Mohs surgery.
cSCC: has risk of nodal metastasis. Excise completely; use Mohs surgery for high-risk tumours; assess nodes.
Melanoma: diagnose by excisional biopsy; prognosis depends mainly on Breslow thickness; treat by wide local excision with thickness-based margins and consider sentinel-node biopsy.
Merkel cell carcinoma: rare and aggressive; treat with surgery, sentinel-node staging, and usually radiotherapy.

Create a comparison table of BCC, SCC, and melanoma

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NCI skin cancer treatment basal cell squamous cell melanoma clinical features diagnosis surgery

Comparison of BCC, SCC, and melanoma

Feature	Basal cell carcinoma (BCC)	Cutaneous squamous cell carcinoma (SCC)	Malignant melanoma
Cell of origin	Basal keratinocytes of epidermis/hair follicle	Squamous keratinocytes of epidermis	Melanocytes
Relative frequency	Most common skin cancer	Second most common skin cancer	Less common, but responsible for most skin-cancer deaths
Major risk factors	Chronic UV exposure, fair skin, age, immunosuppression, prior BCC, radiation, genetic syndromes	Chronic UV exposure, actinic keratosis, Bowen disease, chronic scars/ulcers, immunosuppression, arsenic, HPV in selected sites	Intermittent intense UV exposure and sunburn, fair skin, numerous/dysplastic nevi, family or personal history, immunosuppression
Common sites	Sun-exposed face, nose, eyelids, ears, scalp, neck, upper trunk	Bald scalp, face, ears, lips, neck, dorsal hands, forearms, shins; may occur in chronic wounds	Anywhere. Often trunk/head-neck in men; legs in women; can occur on nail unit, acral skin, mucosa, or eye
Typical appearance	Pearly or translucent papule/nodule; rolled edge; telangiectasia; central ulceration in advanced lesion	Scaly, hyperkeratotic, indurated papule, plaque, or nodule; crusting, ulceration, bleeding	Asymmetric pigmented macule, papule, plaque, or nodule with irregular border and variable colour; may be amelanotic
Useful clinical clue	“Rodent ulcer”: non-healing ulcer with pearly rolled border	Tender, rapidly enlarging keratotic or ulcerated lesion	ABCDE: Asymmetry, Border irregularity, Colour variation, Diameter/enlargement, Evolution
Precursor lesion	No typical obligatory precursor	Actinic keratosis; SCC in situ or Bowen disease	May arise in a pre-existing nevus, but many develop de novo
Growth pattern	Usually slow, locally invasive	Variable, often more rapid than BCC; can invade nerves and deep structures	Radial growth followed by vertical invasion; early potential for lymphatic and blood-borne spread
Local tissue destruction	Can be extensive if neglected, particularly on face	May invade cartilage, muscle, bone, and nerves	Local recurrence/in-transit disease possible; risk rises with thickness
Metastatic potential	Very rare	Definite risk, especially to regional nodes in high-risk tumours	High relative potential, depending especially on Breslow thickness, ulceration, and nodal status
High-risk features	Recurrent, large, ill-defined, aggressive histology, central-face location, perineural invasion, immunosuppression	Size more than 2 cm, deep invasion, poor differentiation, perineural/lymphovascular invasion, ear/lip location, recurrence, immunosuppression	Increased Breslow thickness, ulceration, high mitotic activity, microsatellites, nodal disease
Biopsy approach	Punch, shave, or excisional biopsy according to lesion/site	Punch, shave, incisional, or excisional biopsy according to lesion/site	Prefer complete excisional biopsy with a narrow margin whenever feasible, preserving accurate Breslow thickness
Main treatment	Surgical excision with margin assessment or Mohs micrographic surgery	Surgical excision with margin assessment or Mohs micrographic surgery	Wide local excision after diagnostic biopsy
Role of Mohs surgery	Important for high-risk, recurrent, ill-defined BCC and tissue-critical sites	Important for high-risk/recurrent SCC, aggressive histology, poorly defined margins, and high-risk sites	Not routine for ordinary invasive melanoma; staged margin-controlled techniques may be used in selected melanoma in situ, especially lentigo maligna
Margin principle	Risk-based margin or Mohs margin control	Risk-based margin or Mohs margin control	Margin based on Breslow thickness
Melanoma excision margins	Not applicable	Not applicable	In situ: 0.5 cm; ≤1 mm: 1 cm; >1-2 mm: 1-2 cm; >2 mm: 2 cm
Lymph-node assessment	Usually not needed	Examine nodes; image/biopsy suspicious nodes, especially in high-risk disease	Sentinel lymph-node biopsy is discussed for selected 0.8-1.0 mm lesions and generally recommended/strongly considered for clinically node-negative lesions >1 mm
Advanced disease	Hedgehog-pathway inhibitors or immunotherapy in selected locally advanced/metastatic cases	Radiotherapy and systemic treatment, commonly immunotherapy, in selected advanced disease	Immunotherapy, mutation-targeted therapy when appropriate, radiotherapy, and selected metastasectomy
Overall prognosis	Excellent with adequate treatment	Usually excellent when early, but high-risk disease can recur and metastasize	Depends mainly on stage, especially Breslow thickness and node status

High-yield differences

BCC: most common, pearly rolled edge, locally destructive, metastasis is very rare.
SCC: scaly and keratotic, may arise from actinic keratosis or Bowen disease, can metastasize to regional lymph nodes.
Melanoma: pigmented and changing lesion, assessed by ABCDE rule, prognosis depends mainly on Breslow thickness and nodal involvement.

Surgical exam points

Do not use destructive treatment on a lesion suspicious for melanoma without histology.
BCC and SCC are treated primarily by complete excision or Mohs surgery when margin control and tissue preservation are required.
Melanoma requires diagnostic excision first, then definitive wide local excision based on Breslow thickness.
Check regional lymph nodes in SCC and melanoma. Sentinel-node biopsy has a central staging role in selected melanoma.

Textbook basis: Textbook of Family Medicine, 9e, p. 956; Dermatology 2-Volume Set, 5e, “Invasive cutaneous squamous cell carcinoma”; Sabiston Textbook of Surgery, “Wide Local Excision”; Fitzpatrick’s Dermatology, Vols 1-2, “Surgical Treatment of Primary Melanoma”. The NCI skin cancer treatment summary also lists excision with margin assessment and Mohs surgery as principal local treatments for BCC and SCC.

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