[Rare observation of giant pituitary adenoma spreading into posterior cranial fossa].

A case observation of unusual course of pituitary adenoma is presented. In 47-year old male patient with endo-supra-laterosellar pituitary adenoma and active acromegaly 2 different tumors were discovered intraoperatively during surgery for recurrence of the primary tumor. The first tumor was pituitary adenoma with nuclear polymorphism and the second was meningotheliomatous meningioma with solitary mitoses. After surgery the patient received radiation therapy. After 5 years the patient developed visual deterioration and clinical signs of tumor of left cerebellopontine angle. After removal of posterior fossa lesion, pituitary adenoma was verified.