A 70-year-old woman has a broad-based pigmented mass of the left nasal cavity with destruction of the turbinate. Biopsy shows pleomorphic cells with intracellular melanin; immunohistochemistry is positive for S-100 and HMB-45. Which statement about this tumour is correct?

• A It has the best five-year survival among sinonasal malignancies
• B It carries the worst prognosis of sinonasal malignancies due to early metastasis ✓
• C It is radiosensitive and treated primarily with radiotherapy
• D It commonly arises from the olfactory epithelium of the cribriform plate

Explanation

Primary mucosal melanoma of the nasal cavity and paranasal sinuses has the worst prognosis of sinonasal malignancies, with five-year survival around 20 to 30 percent and a high rate of local recurrence and distant metastasis. It arises from melanocytes in the Schneiderian mucosa, not the olfactory epithelium. Surgery remains the mainstay when feasible; it is relatively radioresistant. Amelanotic variants occur and may be misdiagnosed as undifferentiated carcinoma.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.