Sinonasal teratocarcinosarcoma: a clinicopathologic and immunohistochemical study of 6 cases.

Teratocarcinosarcoma (TCS) is a rare and unusual malignant neoplasm of the sinonasal tract with a heterogenous morphology and an aggressive behavior. Patients are predominantly adults with a male predominance. The aim of this study was to describe clinicopathologic and immunohistochemical features of 6 cases of TCS. The ages ranged from 18 to 67 years (mean, 33 years) with a male-to-female ratio of 5:1. Most tumors were located in the nasal cavity. Nasal obstruction and epistaxis were the common presenting symptoms. Histologically, all tumors exhibited a heterogeneous morphology with varying proportions of benign and malignant epithelial, mesenchymal, and neuroepithelial elements. Adenocarcinoma was the malignant epithelial component in all cases. The mesenchymal elements were composed of benign to malignant spindle cells. Osteosarcomatous areas were seen in 2 cases and rhabdomyosarcoma in 1 case. Rhabdoid differentiation was also seen in 1 case. Immunohistochemical stains CKAE1/AE3 and CK Cam 5.2 were positive in the epithelial elements, vimentin in mesenchymal, and CD56 and neuron-specific enolase in neuroepithelial elements. Follow-up was available in 4 patients and ranged from 21 to 40 months (mean, 31 months). Lung and dura metastasis, respectively, were seen in 1 patient each. However, all 4 patients are alive and free of disease to date. In conclusion, TCS is a rare but highly malignant tumor with aggressive behavior characterized by benign and malignant epithelial, mesenchymal, and neuroepithelial components. Two patients in our series were younger than 20 years. The occurrence of rhabdoid differentiation and osteosarcomatous component seen in our series were rarely described in literature. Recognition of all the components requires adequate sampling, which is crucial for a correct diagnosis.