Prolactinoma as the first manifestation of Gardner's syndrome.

Familial adenomatous polyposis (FAP) is an inherited condition causing numerous adenomatous colorectal polyps and a markedly elevated risk of colon cancer. FAP may be associated with various extracolonic manifestations such as desmoid fibromatosis and osteomas (termed Gardner's syndrome) and brain tumors, usually medulloblastoma or glioma [termed Brain Tumor Polyposis (BTP) syndrome type 2]. We describe a pediatric patient who initially presented with prolactinoma and later was found to have Gardner's syndrome. A germline mutation of the APC (adenomatous polyposis coli) gene was identified. Our case illustrates the association between prolactinoma and FAP, which may represent a rare subtype of Gardner's and BTP syndromes.