Carcinoma of the Maxillary Sinus — Comprehensive Answer

a) Most Probable Diagnosis & Histopathological Types (4 marks)

b) Clinical Features According to Direction of Spread (6 marks)

Ohngren's line — from medial canthus to angle of mandible — Schwartz's Principles of Surgery

1. Medial Wall → Nasal Cavity

• Unilateral nasal obstruction (present)
• Blood-stained / purulent nasal discharge (present)
• Proliferative growth visible in the middle meatus (present)
• Epiphora (nasolacrimal duct involvement)

2. Inferior Wall → Oral Cavity / Hard Palate

• Loosening and displacement of upper molar/premolar teeth (present)
• Ill-fitting dentures
• Palatal swelling, ulceration, or perforation
• Trismus (if pterygoid plates involved)

3. Anterior Wall → Cheek / Face

• Fullness and swelling of the cheek (present)
• Palpable bony hard mass over cheek
• Skin infiltration (late sign)

4. Superior Wall → Orbital Floor

• Proptosis / upward displacement of the globe
• Diplopia (present) — due to infraorbital nerve / inferior rectus involvement
• Infraorbital hypoesthesia / anesthesia (present) — infraorbital nerve compression
• Epiphora from nasolacrimal duct obstruction

5. Posterior Wall → Pterygopalatine Fossa / Infratemporal Fossa

• Trismus (pterygoid muscle invasion)
• Referred otalgia
• Numbness over the cheek, upper lip (V2 involvement)
• Swelling in the temporal fossa

6. Superior–Posterior Extension → Skull Base / Orbit / Brain

• Proptosis
• Visual disturbance / blindness (optic nerve)
• Cavernous sinus syndrome (III, IV, VI cranial nerve palsies)
• Intracranial involvement → headache, seizures (late)

Lymph Node Spread

• Submandibular (Level I) and upper jugular (Level II) nodes most commonly involved
• Occurs in ~25% of sinonasal malignancies at presentation
• Retropharyngeal nodes also at risk

c) Investigations for Diagnosis and Their Justification (5 marks)

1. CT Scan of Paranasal Sinuses (with contrast) — FIRST-LINE

• Role: Evaluates bony erosion and destruction of sinus walls, orbital floor, hard palate, pterygoid plates, anterior skull base
• CT is superior to MRI for bone integrity assessment
• Identifies extent of bony involvement for surgical planning
• T-staging: determines T1–T4 classification (AJCC)
• Detects cervical lymphadenopathy

2. MRI of Paranasal Sinuses (with gadolinium) — COMPLEMENTARY / SUPERIOR for SOFT TISSUE

• Role: Differentiates tumor from trapped/obstructed secretions (tumor shows lower T2 signal; secretions show high T2)
• Superior to CT in 94–98% correlation with surgical findings
• Assesses perineural spread (critical for adenoid cystic carcinoma)
• Detects orbital fat invasion, dural involvement, intracranial extension
• Evaluates cavernous sinus involvement
• Irregular dural thickening >5 mm with enhancement = 100% PPV for dural invasion

3. Biopsy (Histopathological Examination) — DEFINITIVE

• Route: Endoscopic biopsy via nasal cavity / transoral if palatal involvement
• Role: Confirms malignancy, establishes histological type (SCC vs adenocarcinoma vs adenoid cystic etc.)
• Guides choice of chemotherapy and radiation protocol
• Tissue marker studies: p40/p63 (SCC), CK7/CK20, S100 (melanoma), CD20/CD3 (lymphoma), synaptophysin (neuroendocrine)

4. Nasal Endoscopy

• Role: Direct visualisation and assessment of extent of nasal cavity and middle meatus involvement
• Allows guided biopsy
• Assesses resectability and medial extent

5. OPG (Orthopantomogram) / Dental X-ray

• Role: Assesses degree of upper alveolar/molar tooth involvement and mandibular integrity
• Useful before surgery for dental rehabilitation planning

6. Chest X-ray / CT Chest

• Role: Screens for pulmonary metastases (distant spread)
• Part of staging workup

7. PET-CT (if available)

• Role: Detects occult nodal and distant metastases
• Guides radiation field planning

8. Blood Investigations

• CBC, LFT, RFT — baseline before chemotherapy/surgery
• Serum calcium — if bony involvement extensive

d) Management (Medical + Surgical Indications) (marks)

STAGING (AJCC T-Classification — Maxillary Sinus)

MEDICAL MANAGEMENT

• Platinum-based regimens: Cisplatin + 5-Fluorouracil (PF) or TPF (Docetaxel + Cisplatin + 5-FU)
• Used in locally advanced / borderline resectable disease to downstage tumor
• Facilitates organ preservation (orbit, palate)

• Cisplatin (100 mg/m² every 3 weeks) concurrent with radiation
• Used postoperatively when adverse features present (positive margins, perineural invasion, nodal involvement with extracapsular spread)
• Also used as primary definitive treatment in unresectable T4b disease

• Cetuximab (anti-EGFR): Used in recurrent/metastatic SCC when cisplatin is contraindicated
• Pembrolizumab / Nivolumab (PD-1 inhibitors): For recurrent/metastatic disease, especially PD-L1–positive tumors

• Definitive RT: For unresectable disease or patients unfit for surgery
• Dose: 60–70 Gy in conventional fractionation
• Modern techniques: IMRT (intensity-modulated RT) reduces dose to orbit, brain, optic structures
• Postoperative adjuvant RT: 60–66 Gy, started within 6 weeks of surgery

SURGICAL MANAGEMENT

• Resectable T1–T4a disease without involvement of orbital apex, dura, brain, or clivus
• T4b features (orbital apex, dura, brain) generally render the tumor unresectable
• Orbital exenteration is indicated when orbital fat is invaded; periorbita alone does not require exenteration

A. Infrastructure Maxillectomy (below Ohngren's line)

• Removes: floor and walls below the infraorbital nerve
• Indications: T1–T2, tumors confined to lower half of maxillary sinus, alveolus, palate
• Approach: transoral / sublabial

B. Total Maxillectomy (Total / Radical)

• Removes: entire maxilla including orbital floor
• Indications: T2–T3, tumors involving the full sinus
• Approach: Weber-Ferguson incision (lateral rhinotomy extended below the nostril, through upper lip to gingival sulcus)
• May include orbital floor resection; orbital contents preserved if periorbita intact

C. Total Maxillectomy + Orbital Exenteration

• Indications: Tumor invading orbital fat (not just bony orbit)
• Radical procedure; significant functional and cosmetic deficit

D. Craniofacial Resection

• Indications: Tumor involving cribriform plate or anterior skull base
• Combined neurosurgical + ENT approach
• Removes ethmoids, cribriform plate, sometimes dura

E. Neck Dissection

• Selective neck dissection (levels I–III) indicated when clinically node-positive
• Elective neck dissection considered for N0 neck when tumor > T2 (high occult nodal risk)

RECONSTRUCTION

• Prosthetic obturator: for palatal defects after maxillectomy
• Free flaps (anterolateral thigh, rectus abdominis): for large soft tissue defects
• Titanium mesh / orbital implants for orbital floor reconstruction

SUMMARY ALGORITHM

Biopsy-proven maxillary sinus carcinoma
         ↓
  Staging (CT + MRI + CXR ± PET-CT)
         ↓
  ┌──────────────────────────────────┐
  │ Resectable (T1–T4a)             │  Unresectable (T4b)
  │                                  │
  │  Surgery (Maxillectomy)          │  Concurrent chemoradiation
  │  + Postop RT ± Chemo            │  or palliative chemotherapy
  └──────────────────────────────────┘

Key Teaching Points for This Case

• The diplopia + infraorbital hypoesthesia indicate superior wall / orbital floor breach (T3 at minimum)
• Loosening of teeth = inferior wall involvement
• Cheek fullness = anterior wall erosion
• This patient has spread in ≥3 directions → likely T3 or T4a disease
• Most patients present with advanced disease because the sinus acts as a "silent" compartment in early stages