Association of oligodendroglioma-like cell proliferation and angiomatous vasculature--coincidence or pathogenetically related lesions?

We report a case of an oligodendroglioma associated with a cavernous angioma. The patient, a 20-year-old man with an 8-year history of epileptic seizures, presented an acute onset of headache, nausea, and vomiting. Computerized tomographic scan and angiogram revealed multiple vascular malformations in both hemispheres including a cystic hemorraghic lesion with a perifocal edema attributing to a mass effect. Repeated puncture of the cyst failed to give improvement of elevated intracranial pressure. At surgery, the cyst and the underlying lesion were excised and found to be oligodendrocyte-rich tissue with malformed vascular tissue. Final histological examination revealed an oligodendroglioma associated with a cavernous angioma. As concurrence of oligodendroglioma and vascular malformation is rare, this case raises a broad range of differential diagnoses such as reactive oligodendroglial gliosis due to a vascular malformation, unusual vascularity of an oligodendroglioma as well as other kinds of cerebral tumors or malformations. The diagnostic difficulties as well as the pathogenetic and pathological significance of the concurrence of an oligodendroglioma and cavernous angioma are discussed.