Cerebral primitive neuroectodermal tumor in an adult with a heterozygous MSH2 mutation.

BACKGROUND: A 37-year-old woman presented with a supratentorial cerebral mass, which was diagnosed histologically as a primitive neuroectodermal tumor. She had been treated for rectal adenocarcinoma 7 years previously. A family history revealed a young-onset colorectal carcinoma in the patient's father. INVESTIGATIONS: Immunohistochemical analysis for DNA mismatch repair proteins, germline mutation analysis of MSH2. DIAGNOSIS: Lynch syndrome with a heterozygous germline mutation in MSH2. MANAGEMENT: Debulking of the cerebral tumor, craniospinal axis radiotherapy, and genetic counseling of family.