Sinonasal Malignancies

Intro & Risks - Sinus Danger Signs

• Definition: Malignant neoplasms arising from the nasal cavity and paranasal sinuses.
• Common Sites (in decreasing order): Maxillary sinus > Nasal cavity > Ethmoid sinuses > Sphenoid/Frontal sinuses.
• Epidemiology: Predominantly affects older males (typically 50-70 years). Indian epidemiology highlights links to tobacco and specific occupational exposures.
• Key Risk Factors:
  • Occupational: Wood dust (adenocarcinoma), nickel, chromium, leather dust. 📌 Mnemonic: "Workers Near Chemicals & Lumber"
  • Smoking: Strong association, particularly for Squamous Cell Carcinoma (SCC).
  • Viral Infections: HPV (implicated in some Sinonasal Papillomas with malignant transformation and some SCCs), EBV (associated with NK/T-cell lymphoma).

⭐ Maxillary sinus is the most common site for sinonasal malignancies.

Tumor Types & Spread - The Nasty Neighbors

• Local Invasion: Orbit, skull base, pterygopalatine fossa.
• Lymphatic Spread: Neck nodes; often late (except high-grade tumors).
• Hematogenous Spread: Rare.

⭐ Esthesioneuroblastoma (Olfactory Neuroblastoma) arises from the olfactory epithelium in the superior nasal cavity and is graded by Hyams system.

Clinical Features & Diagnosis - Spotting the Suspects

• Presentation often late; unilateral symptoms are key red flags.
  • Nasal: Obstruction, epistaxis, rhinorrhea, anosmia.
  • Facial: Pain, swelling, paresthesia (CN V2 common).
  • Ocular: Proptosis, diplopia, epiphora, visual loss (orbital invasion).
  • Oral: Dental pain, loose teeth, palatal bulge.
• ⚠️ Red Flags: Persistent unilateral symptoms, cranial neuropathies (e.g., CN V2), orbital signs.
• Diagnostic Workup:
  • Nasal endoscopy + Biopsy: CRUCIAL for diagnosis.
  • Imaging:
    • CECT: Details bone erosion, tumor extent.
    • MRI: Assesses soft tissue, perineural spread, intracranial extension.
    • PET-CT: For staging & detecting metastases.

⭐ Ohngren's line (medial canthus to angle of mandible) divides maxillary sinus tumors: anteroinferior (better prognosis) vs. posterosuperior (worse prognosis). 📌

Staging & Management - The Battle Plan

• Staging: AJCC TNM (8th Ed.). General principles; site-specific considerations vital.
• Treatment Principles: Multimodal therapy standard; MDT approach crucial.
  • Surgery: Primary for most resectable tumors (Endoscopic vs. Open). Goal: R0 resection.
  • Radiotherapy (RT): Adjuvant (e.g., positive margins, PNI), Definitive (unresectable), Palliative. IMRT preferred.
  • Chemotherapy (CT): Induction, Concurrent (e.g., Cisplatin with RT), Palliative. Role in specific histologies.

⭐ Perineural invasion (PNI) is a significant adverse prognostic factor in sinonasal malignancies, often necessitating adjuvant radiotherapy.

• Key Prognostic Factors: Stage, histology, grade, PNI, surgical margins, orbital/intracranial extension.

High‑Yield Points - ⚡ Biggest Takeaways

• Maxillary sinus is the most common site for sinonasal malignancies.
• Squamous Cell Carcinoma (SCC) is the most frequent histological type.
• Wood dust exposure is a key risk for ethmoid adenocarcinoma.
• Inverted papilloma carries risk of malignant transformation to SCC.
• Esthesioneuroblastoma arises from olfactory epithelium; uses Kadish staging.
• Ohngren's line divides maxillary tumors, impacting prognosis.
• Nickel exposure is a risk for nasal cavity SCC and ethmoid SCC.