Sinonasal carcinosarcoma with cartilaginous and rhabdomyoblastic components: A previously undescribed entity.

Carcinosarcomas are rare, aggressive tumors seldom found in the sinonasal region. They classically consist of sarcomatous spindle cell and carcinomatous squamous cell elements. A 61-year-old woman presented reporting right-sided nasal discharge and obstruction. Examination demonstrated a large right-sided nasal mass, from which a biopsy was taken. Computed tomography and magnetic resonance imaging revealed a mass arising from the maxillary antrum and extending into the nasal cavity, ethmoid air cells, and frontal sinus. Right total maxillectomy with resection of the nasal tumour component was performed. Histological analysis demonstrated a high-grade malignancy with features consistent with carcinosarcoma with cartilaginous and rhabdomyoblastic elements, a histologic pattern that has not previously been described at this site. Magnetic resonance imaging 5 weeks postoperatively showed sizeable recurrence. Adjuvant chemotherapy and radiotherapy were commenced to excellent effect. Carcinosarcomas, though very rare at sinonasal sites, should be considered if biopsy demonstrates undifferentiated high-grade neoplasm with cytokeratin expression. These tumors require aggressive multimodal therapy for optimal outcomes.