Immature Teratoma with Somatic Tumor-Type Sarcoma: A Case Report.

Teratoma is a germ cell tumor seen mainly in neonates and young adults; it contains elements derived from all three germinal layers, with its usual site of occurrence being the ovary and testis and less common sites being several extragonadal locations. This case is of a 10-year-old boy who presented with an asymptomatic mass, heterogenous on ultrasonography and showing enhanced solid areas along with nonenhancing cystic areas on contrast enhanced computed tomography. Cytological diagnosis of malignant mesenchymal tumor was made; however, exact categorization could not be done. After surgical excision, histological and immunohistochemical studies yielded the diagnosis of immature teratoma with somatic malignancy – sarcoma. Teratomas with malignant transformation refer to a form of germ cell tumor in which a somatic teratomatous component becomes morphologically malignant and develops aggressively. These are associated with chromosomal abnormalities i (12p) reflecting germ cell tumor clonality. The occurrence of an identifiable sarcomatous component is a well recognized but distinctly uncommon phenomenon.