Primary mucosal melanomas in nasal cavity: a clinicopathological analysis of 18 cases

Objective To study the clinicopathological features of the primary mucosal melanomas in the nasal cavity and to discuss its diagnosis and differential diagnosis.Methods The clinical data were reviewed retrospectively and immunohistochmical stains were performed in 18 case of the primary mucosal melanomas in the nasal cavity.Results The patients were 7 males and 9 females,aged from 34 to 75 years(mean 55.9 years).The lesions were mainly located in the nasal cavity,or a combination of the nasal cavity and sinuses.Histologically,the tumors were composed of a variety of cell types (epithelioid,spindle,undifferentiated),frequently arranged in a peritheliomatous pattern.Immunohistochemical stain showed the tumors were positive for HMB45,S-100 and vimentin. Conclusion To compare with melanoma in the skin,primary nasal cavity melanoma has different histological features.The diagnosis is often difficult.Based on the histopathologic features and immunohistochemical finding,it can be differentiated from other tumors derived from nasal cavity.