Progressive tentorial cavernous malformation

BACKGROUND: Because extra-axial cavernous malformations (CMs) are rare, the common clinical course remains unclear. We report the case of a patient with progressive CM originating from the cerebellar tentorium. CASE DESCRIPTION: A 64-year-old woman was admitted to our hospital with the complaint of diplopia. Magnetic resonance (MR) imaging revealed a lesion attached to the left cerebellar tentorium, close to the cerebral peduncle. This well-demarcated lesion rapidly enlarged for 3 months and eroded into the midbrain. Cerebral angiography showed a branch of the middle meningeal artery supplying the lesion and pooling of the contrast medium in the venous phase. A dark reddish and mulberry-like mass of the tentorium was observed intraoperatively, allowing the diagnosis of a tentorial CM. The feeding artery was identified in the tentorium and was coagulated. Postoperative MR imaging showed remarkable mass reduction and central necrosis of the lesion. However, the lesion recurred in 3 months; consequently, gamma knife radiosurgery was performed. After an additional 2 months, the lesion shrank in response to the radiosurgery. CONCLUSIONS: We report an extremely rare case of tentorial CM which showed rapid growth in a short period. Coagulation of the feeding artery was not sufficient to control the lesion. Gamma knife radiosurgery may prove highly effective for recurrent lesions.