Neuroendocrine neoplasms of gastrointestinal tract and secondary primary synchronous tumors: A systematic review of case reports. Casualty or causality?

Background: Neuroendocrine neoplasms (NENs) can arise in most of the epithelial organs of the body and are not a rare condition in the gastrointestinal tract (GIT). The presence of NENs in GIT associated with other secondary primary malignancies (SPM) has been considered an exotic event. This study aims to describe the case reports of NENs accompanied by synchronous primary tumors.

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 hamartomatous 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.