Endocrine inactive and gonadotroph adenomas: diagnosis and management.

Endocrine inactive pituitary adenomas represent about one quarter of all pituitary tumors. By immunocytochemistry, most of these tumors are positive for intact gonadotropins and/or their subunits. Clinical presentation is usually secondary to mass effect symptoms, such as visual disturbances, headache, and hypopituitarism. Differential diagnosis is usually accomplished by neuroradiologic studies, even though in selected cases positron emission tomography and/or single photon emission tomography may aid to distinguish pituitary adenomas from other endocrine inactive lesions, such as meningiomas and craniopharyngiomas. Surgical management is usually considered the first choice treatment for patients with endocrine inactive pituitary adenomas because it is very effective in ameliorating symptoms of chiasmal compression and headache. Radical removal of the tumor, however, is difficult to obtain because of the frequent invasiveness into the cavernous sinus. Radiation therapy diminishes the likelihood of tumor recurrence, especially in patients with demonstrable tumor remnants after surgery. Medical therapy with dopaminergic drugs, somatostatin analogs, or gonadotropin-releasing hormone agonists or antagonists causes mild reduction of tumor size in few patients and, therefore, seems to be of limited value in the therapeutic management of patients with endocrine inactive pituitary adenomas.