Enchondromatosis-associated oligodendroglioma: case report and literature review.

Enchondromatosis is a rare skeletal disorder characterized by the development of multiple enchondromas, which can also manifest non-cartilage tumors including gliomas. Here, we describe a genetic analysis of a low-grade glioma that developed in an enchondromatosis case. A 32-year-old man with a long history of enchondromatosis developed a left frontal tumor. The histopathological findings of his surgical specimen revealed characteristics of a low-grade glioma with an IDH1 c.395G>A (R132H) mutation and 1p/19q codeletion, which led to a definitive diagnosis of oligodendroglioma. A common point mutation in IDH1 (R132H) was detected in the patient's enchondroma and glioma-matched pair specimens. To the best of our knowledge, this is the first case of molecularly confirmed oligodendroglioma associated with enchondromatosis. Furthermore, identification of a common IDH1 mutation in enchondroma and oligodendroglioma-matched pair specimens supports the hypothesis that IDH1/2 mosaicism initiates tumorigenesis.