A rare case of carcinosarcoma of the maxillary sinus with osteosarcomatousdifferentiation

A unique case of carcinosarcoma in the maxillary sinus is reported. A 47-ye ar-old man visited our hospital with complaints of right nasal obstruction and bloody rhinorrhea. Examination revealed a hemorrhagic mass with necrosi s in the maxillary sinus that infiltrated the right nasal cavity. Histologi cally, the tumor was composed of both carcinomatous and sarcomatous element s. Nests of squamous cell carcinoma and adenocarcinoma were scattered in th e sarcomatous element with osteosarcomatous differentiation. No distinct de marcation between the two elements was observed and some spindle-shaped cel ls in the sarcomatous component were immunoreactive to epithelial markers b y immunohistochemical staining. Although the histogenesis of carcinosarcoma remains unclear, the histologic pattern of the present case indicates the possibility that a multipotential cell, capable of both epithelial and mese nchymal differentiation, was the origin of the rare tumor. (C) 2001 Elsevie r Science Ireland Ltd. All rights reserved.