Paranasal Sinus Cancer

Paranasal sinus cancers are rare malignant tumors arising from the maxillary (60-70%), ethmoid (10-20%), sphenoid, or frontal sinuses, and the nasal cavity. Histology is diverse: squamous cell carcinoma (most common), adenoid cystic carcinoma, sinonasal undifferentiated carcinoma (SNUC), olfactory neuroblastoma (esthesioneuroblastoma), adenocarcinoma (intestinal-type from wood dust exposure), salivary-gland-type tumors, melanoma, sarcoma, and lymphoma.

These cancers are often diagnosed at advanced stage because early symptoms mimic chronic sinusitis. Local extension to orbit, skull base, intracranial structures, and pterygoid space is common, complicating resection. Lymph node metastasis is less frequent than other head and neck cancers (10-20%) due to limited lymphatic drainage.

Risk factors include occupational exposures (wood dust for adenocarcinoma, nickel for squamous, leather dust, formaldehyde, chromium), tobacco smoking, HPV (small subset), and prior radiation. Diagnosis combines nasal endoscopy with biopsy, CT and MRI of paranasal sinuses with skull base, PET-CT for staging, and ophthalmology evaluation. Treatment is multidisciplinary with endoscopic or open craniofacial resection, adjuvant intensity-modulated or proton radiotherapy, and concurrent chemotherapy in selected cases. Esthesioneuroblastoma may benefit from neoadjuvant chemotherapy. Multimodality approaches improve 5-year survival from below 30% (older series) to 50-60% in modern era.