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Hydrocele vs Lipoma vs Sebaceous Cyst vs Dermoid Cyst

Surgical Case Discussion - Complete Comparison

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1. HYDROCELE

Definition

• Bailey and Love's Short Practice of Surgery, 28th ed.

Classification

Clinical Features (Surgical Exam Points)

1. Can you get above the swelling? - Yes in hydrocele (distinguishes from inguinoscrotal hernia)
2. Is the testis palpable? - A hydrocele encloses both testis and epididymis - they may be impalpable
3. Transillumination - Hydroceles transilluminate brightly (positive test)
4. Painless, slow growing; reaches large size before presentation
5. Be wary of acute hydrocele in a young man - rule out testicular tumour
6. In congenital type: intermittent, may reduce when lying down
7. Hydrocele of cord: moves downward when testis is pulled down (differentiates from hernia)

Investigation

• Ultrasound - mandatory when testis is impalpable; excludes testicular malignancy

Key rule: If a tumour is suspected, the hydrocele must NOT be punctured (risk of malignant needle-track implantation)

Treatment

• Small, asymptomatic: conservative observation
• Large / symptomatic: Surgery is the mainstay

• Congenital hydrocele: Herniotomy (ligation of patent processus vaginalis) if it does not resolve by 18 months

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2. LIPOMA

Definition

• Sabiston Textbook of Surgery, 21st ed.

Clinical Features

• Soft, lobulated, non-tender, subcutaneous swelling
• Smooth surface, well-defined edges; fluctuant or pseudo-fluctuant
• Slipping sign: when pressed laterally, it slips away under the fingers
• Brilliantly does NOT transilluminate (solid fat)
• Does NOT have a punctum
• May be much more extensive than surface appearances suggest (especially axilla, supraclavicular region)
• Multiple lipomas: consider familial lipomatosis

Red Flags (Lipoma vs Liposarcoma)

• Size >10 cm
• Thick septa (>2 mm)
• Non-adipose areas within tumour
• <75% adipose tissue composition

Treatment (Surgical)

• Simple excision beyond the capsule of the tumour
• Technique (Pye's Surgical Handicraft):
  • Anaesthesia: local infiltration for small; general for large/multiple
  • Squeeze the overlying tissues to make the lipoma bulge forward
  • Incision down to the capsule, then enucleation
  • For large/multilocular: establish line of cleavage, remove with blunt + sharp dissection
  • Meticulous haemostasis; obliterate dead space or insert small suction drain if extensive dissection
• Note: Liposarcoma requires wide excision with negative margins and multidisciplinary team input

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3. SEBACEOUS CYST (Epidermoid Cyst)

Definition

• Schwartz's Principles of Surgery, 11th ed.

Clinical Features

• Dermal or subcutaneous cyst with a characteristic single keratin-plugged punctum at the skin surface
• Common in adult men and women; upper chest, back, face, scalp
• Firm, spherical, smooth, non-tender
• Attached to skin at the punctum; mobile over deeper structures
• Does NOT transilluminate
• Infected sebaceous cyst: red, tender, fluctuant; may discharge pus through punctum

Types of Cutaneous Cysts (Surgical Distinction)

Treatment (Surgical)

• Anaesthesia: local infiltration; general if multiple
• Elliptical incision centred on the punctum (rather longer than the cyst, about 1/3 of its diameter wide)
• Dissect away the ellipse taking care not to rupture the cyst
• Seek the line of cleavage and shell out the intact cyst
• If rupture occurs: all epithelium must be meticulously dissected away to prevent recurrence
• Haemostasis; obliterate dead space with absorbable sutures; close skin

Key rule: If any epithelium is left behind, the cyst will recur. Total removal of the cyst lining is mandatory.

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4. DERMOID CYST

Definition

• Andrews' Diseases of the Skin, 13th ed.; Schwartz's Principles of Surgery, 11th ed.

Sites (Embryonic Fusion Lines)

• External angular dermoid - above the lateral end of the eyebrow (most common site)
• Nasal root, forehead midline
• Floor of the mouth
• Midline scalp (frontal to occipital)
• Chest, back, abdomen, perianal area
• Spinal column (in spina bifida patients)

Clinical Features

• Few mm to several cm diameter; located in subcutaneous fat
• Firm, cystic, non-pulsatile
• Does NOT transilluminate
• Tethered to underlying tissues (may have underlying bony defect)
• NOT attached to overlying skin (unlike sebaceous cyst)
• No punctum typically (though a sinus opening may sometimes be present with a tuft of hair)
• 70% identified by age 5 years; may present in first year of life
• Genetic component in nasal and external angular dermoids (familial)

Histology

• Cyst wall: keratinizing stratified squamous epithelium with skin appendages (lanugo hair, sebaceous glands, sweat glands)
• Wavy eosinophilic "shark tooth" pattern may be seen in portions of the lining

Complications

• Rupture with foreign body reaction / infection
• If over spinal midline: may connect to CNS - intracranial infection / meningitis possible
• If over lower spine: associated with tethered cord and ambulatory difficulties

Treatment (Surgical)

• Pre-operative imaging is mandatory for midline cysts: CT or MRI to rule out intracranial/intraspinal communication
  • Any bony changes on CT must be followed up with MRI
  • If intracranial connection detected: refer to neurosurgeon before any local excision
• Do NOT attempt surgical removal or biopsy of a cyst over cleavage planes (including midline back) without proper assessment
• Lateral eyebrow dermoids: may be excised without imaging
• Surgical excision with care to remove the entire cyst lining to prevent recurrence
• Implantation dermoid (hands/feet): local or digital block, bloodless field, incision along skin crease, enucleation; skin closure often not necessary

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MASTER COMPARISON TABLE (Case Discussion Rapid Reference)

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KEY SURGICAL PEARLS FOR CASE DISCUSSION

1. Hydrocele: Always do ultrasound before aspiration in any acquired hydrocele in a young man - never aspirate if malignancy is suspected (needle track implantation risk). Lord's procedure preferred for thin-walled sacs (less haematoma risk).
2. Lipoma: The "slipping sign" is characteristic. Warn the patient that deep/large lipomas (especially axilla, supraclavicular) may be more extensive than they appear. Always suspect liposarcoma if size >10 cm, rapid growth, or MRI shows thick septa.
3. Sebaceous cyst: The punctum is the diagnostic hallmark. When infected, drain first, excise the wall electively later (excising an acutely infected cyst risks incomplete removal and recurrence). All lining must be removed.
4. Dermoid cyst: Never confuse the external angular dermoid (mobile, lateral eyebrow) with a sebaceous cyst - dermoid is deeper, attached to periosteum/bone, no punctum. Always image midline and posterior scalp dermoids before operating - connection to brain or spinal cord is possible.

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PERIPHERAL VASCULAR DISEASE (PVD)

Surgery Long Case Presentation - Complete Guide

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PART 1: CASE PRESENTATION STRUCTURE

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PRESENTING COMPLAINT

• Pain in the calf/thigh/buttock on walking (intermittent claudication)
• Pain in the foot/toes at rest (rest pain)
• Non-healing ulcer / blackening of toes (gangrene)
• Sudden onset severe limb pain (acute on chronic)

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PART 2: HISTORY OF PRESENTING COMPLAINT

Intermittent Claudication - Ask Specifically:

Rest Pain - Key Features:

• Occurs at night (recumbent position removes gravity-assisted flow)
• Located in forefoot/toes
• Patient hangs leg out of bed or sleeps sitting up
• Relieved by dependency (gravity increases perfusion)

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RISK FACTORS (MUST mention all in presentation)

• Smoking (single most important risk factor - causes vasospasm + accelerates atherosclerosis)
• Diabetes mellitus (causes micro + macrovascular disease; also peripheral neuropathy masking symptoms)
• Hypertension
• Hyperlipidaemia (especially elevated LDL)
• Obesity
• Sedentary lifestyle

• Age >50 years
• Male sex (3:1 over females; post-menopausal women equalise)
• Family history of cardiovascular/peripheral vascular disease

• Buerger's disease (thromboangiitis obliterans) - young male smokers, small vessel occlusion
• Takayasu's arteritis - young women
• Popliteal artery entrapment syndrome - young athletes

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PAST HISTORY

• Previous MI, stroke, TIA (cardiovascular risk)
• Previous vascular interventions (angioplasty, bypass)
• Previous amputation
• Renal disease (contrast nephropathy risk for angiography)

DRUG HISTORY

• Antiplatelet agents (aspirin, clopidogrel)
• Statins
• Antihypertensives
• Beta-blockers (note: relatively contraindicated in severe PVD - may worsen claudication)
• Anticoagulants

SOCIAL HISTORY

• Smoking - pack-years (most important)
• Occupation, walking demands
• Functional status and independence
• Social support (especially if amputation being considered)

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PART 3: EXAMINATION - SYSTEM ORDER

GENERAL INSPECTION

• Looks of chronic illness, cachexia
• Cigarette staining of fingers
• Evidence of xanthelasmata, corneal arcus (hyperlipidaemia)
• Diabetic skin changes

VASCULAR EXAMINATION SEQUENCE (Present in this order)

1. Inspection of the Limb

2. Palpation

• Temperature: Start from foot and work proximally; compare both limbs
• Capillary refill time: Normal <2 seconds
• Pulses: Examine ALL pulses bilaterally and compare

Bailey's Point: Popliteal pulse that is prominent/easily felt = suspect popliteal aneurysm

• Bruit on auscultation: Femoral triangle (iliac/femoral stenosis); also auscultate abdomen for aortic bruit

3. Buerger's Test

1. Elevate leg to 45° - look for pallor (positive if occurs within 2 minutes)
2. Then allow limb to hang dependently - look for reactive hyperaemia (rubor of dependency)

• Buerger's angle = angle at which pallor appears; normal >90°; <20° = critical ischaemia

4. Neurological Assessment

• Sensation (neuropathy masks ischaemic symptoms in diabetics)
• Motor power of foot
• Reflexes (absent ankle jerks = peripheral neuropathy)

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ULCER EXAMINATION (If present - describe fully)

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PART 4: CLASSIFICATION - FONTAINE & RUTHERFORD

Fontaine Classification (Bailey & Love / Schwartz)

Rutherford Classification (Schwartz's Principles of Surgery)

Viva Point: Fontaine III + IV = "Critical Limb Ischaemia (CLI)" - also defined as rest pain + ABI <0.4, or ankle pressure <50 mmHg, or toe pressure <30 mmHg

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PART 5: INVESTIGATIONS

Non-invasive

1. Ankle-Brachial Pressure Index (ABPI)

• Definition: Ratio of ankle systolic pressure (using Doppler) to brachial systolic pressure
• Technique: Sphygmomanometer cuff + handheld Doppler; measure both posterior tibial and dorsalis pedis; use the higher value

Viva Point: If ABPI is falsely elevated (>1.3), use toe-brachial index (TBI) or pulse volume recordings (PVR) instead

2. Duplex Ultrasound (Colour Duplex Scan)

• First-line imaging investigation
• Shows stenosis: peak systolic velocity ratio ≥2.5 at stenosis = >75% diameter reduction
• Monophasic waveform = significant proximal disease
• Maps disease for intervention planning

3. Exercise ABPI

• Walk on treadmill; repeat ABPI immediately after
• Normal: no drop in ABPI
• Claudication: ABI drops, then recovers within 3-5 minutes

Vascular Imaging

Systemic Investigations

• FBC (anaemia worsens ischaemia; polycythaemia increases thrombosis risk)
• Blood glucose and HbA1c (diabetes control)
• Lipid profile
• U&E and creatinine (contrast nephropathy risk; renal artery disease co-exists)
• Coagulation screen
• ECG and echo (cardiac risk assessment before surgery - most PVD patients die of MI)
• CXR

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PART 6: MANAGEMENT

Conservative Management (Fontaine I-IIa)

Endovascular Treatment (Fontaine IIb-IV, TASC A/B lesions)

TASC Guide (Schwartz's): TASC A/B = endovascular first; TASC C = endovascular preferred if patient unfit for surgery; TASC D = surgery preferred

Surgical Treatment

Bypass Surgery

Bailey's Key Point: The long saphenous vein (LSV) is the best conduit - reversed vein graft or in-situ technique (with valvulotome). PTFE has poor patency below the knee. If LSV is unavailable, alternatives include arm veins, short saphenous vein, or composite grafts.

Embolectomy (Acute Limb Ischaemia)

• Fogarty balloon catheter technique via femoral arteriotomy
• Extract clot both proximally (antegrade bleeding) and distally (back-bleeding)
• Completion angiography to confirm clearance
• Fully anticoagulate post-operatively

Endarterectomy

• Reserved for focal iliac / common femoral artery disease
• Common femoral endarterectomy (CFE) + patch angioplasty is standard for CFA disease

Profundaplasty

• Surgical widening of profunda femoris origin
• Indication: critical ischaemia with patent profunda when SFA occluded
• Profunda femoris is the key collateral supplying the thigh

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PART 7: ACUTE LIMB ISCHAEMIA (ALI) - THE 6 P's

Classic Presentation

Viva Point: Paraesthesia and paralysis are the most important signs indicating threatened limb - requires emergency revascularisation within 6 hours. Paralysis indicates advanced ischaemia and may be irreversible.

Embolism vs Thrombosis (Classic Viva)

Rutherford Classification of ALI

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PART 8: LERICHE SYNDROME (Aortoiliac Occlusion)

1. Bilateral buttock and thigh claudication
2. Impotence (due to internal iliac artery occlusion)
3. Absent femoral pulses bilaterally

• Occurs in younger patients (~50s) compared to femoropopliteal disease
• Limb-threatening ischaemia rare in isolation (collaterals form)
• Treatment: aortobifemoral bypass or aortoiliac angioplasty/stenting

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PART 9: AMPUTATIONS

Indications for Primary Amputation

• Irreversible ischaemia (Rutherford Class III ALI)
• Failed revascularisation
• Extensive wet gangrene / overwhelming sepsis
• No suitable distal vessel for bypass
• Non-ambulatory patient with dead limb

Amputation Levels (from distal to proximal)

Bailey's Rule: Every effort should be made to preserve the knee joint - BKA is far superior functionally to AKA. A BKA stump requires 40-60% more energy to mobilise; AKA requires 60-100% more.

Assessment for Amputation Level

• Skin blood flow assessment (TcPO2 - transcutaneous oxygen tension)
• Doppler pressure at proposed level
• Clinical: bleeding at skin incision (best indicator of healing potential)

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PART 10: VIVA QUESTIONS AND ANSWERS

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SUMMARY BOX - WHAT TO SAY AT THE END OF LONG CASE

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