Primitive neuroectodermal tumors of the central nervous system associated with genetic and metabolic defects.

Aim: To evaluate the genetic, congenital and metabolic disorders which were detected concurrently with primitive neuroectodermal tumors (PNET) of the central nervous system in children.

Methods: Medical records of 1030 children who were admitted to our department with diagnosis of brain tumor between 1975 and 2005 were reviewed retrospectively. Medulloblastoma and supratentorial PNETs were detected in 289 patients. They were reviewed for associated metabolic conditions, genetic and congenital defects.

Results: One of the following conditions were detected in 10 patients with medulloblastoma and supratentorial PNETs: Neurofibromatosis type 1, Gorlin syndrome, juvenile polyposis coli, cancer prone syndrome of total premature chromatid separation and Fanconi anemia, bilateral retinoblastoma, L-2-hydroxyglutaric aciduria, Gilbert syndrome, gray platelet syndrome, cleft lip-palate and left renal agenesis. In the patients with multiple malignant diseases, cancer prone syndrome of total premature chromatid separation and Fanconi anemia, Gorlin syndrome and juvenile polyposis coli were diagnosed after diagnosis of the malignant tumors. Medulloblastoma was the first manifestation in the case with Gorlin syndrome. In case with retinoblastoma, pineal PNET was detected 2 months after diagnosis of retinoblastoma. Cleft lip-palate and L-2-Hydroxyglutaric aciduria were detected previously in the patients before their brain tumors whereas Gray platelet, Gilbert syndrome and left renal agenesis were diagnosed during treatment of medulloblastoma.

Conclusion: Associated genetic, metabolic and congenital conditions were detected in 3.5% of the cases. Thus the patients with PNET should be followed for these defects.