De novo appearance of cerebellar cavernous malformation in a patient with moyamoya disease: case report and review of the literature.

The authors report a case of cerebellar cavernous malformation associated with moyamoya disease. An adolescent male with moyamoya disease had undergone bilateral direct and indirect extracranial-intracranial anastomosis at 11 years of age, and the course had been uneventful until MRI detected the appearance of a cavernous malformation in the cerebellum 3 years later. The lesion had grown, bled, and caused headache and disturbance of consciousness 2 years after the initial detection. The cavernous malformation was removed surgically and pathologically verified. The patient has recovered without any neurological deficits. This is a quite rare case with cavernous malformation which appeared in a moyamoya disease patient. The association of the two different vascular disorders in a young patient may suggest the existence of some interaction in the pathogenesis of these diseases. Since cavernous malformations with a de novo appearance may grow and become clinically significant, careful observation is necessary.