Carcinosarcoma with choriocarcinomatous and osteosarcomatous differentiation in a patient with juvenile polyposis syndrome.

Juvenile polyposis syndrome (JPS) is an infrequent autosomal dominant hereditary predisposition to the occurrence of hamar-tomatous polyps in the colon and rectum. We describe the case of a 12-year-old boy with JPS associated with an abdominal tumor. Histological sections of the abdominal tumor showed components of adenocarcinoma, osteosarcoma, and choriocarcinoma. Immunohistochemistry was AE1/AE3, CK7, HCG and SALL4 positive. Juvenile polyposis syndrome patients are at increased risk of colorectal adenocarcinoma. However, we present a case of an adenocarcinoma associated with other unusual components. This association has not been reported before. [ABSTRACT FROM AUTHOR]