Malignant transformation of nasal inverted papilloma into sarcomatoid carcinoma.

A 57 year-old, male presented with a chronic unilateral nasal obstruction and epistaxis. Intranasal endoscopy showed multiple polypoid lesions. The computed tomography exam revealed a heterogeneous mass that occupied the right nasal cavity with osteolysis of the middle and lower cone causing fluid retention of the right maxillary sinus. He underwent resection of these lesions. Pathological examination revealed malignant transformation of nasal inverted papilloma into sarcomatoid carcinoma. This case report highlights the importance of considering malignant transformation in the differential diagnosis of polypoid lesions.