Pituitary apoplexy This syndrome, described originally by Brougham and colleagues, occurs as a result of infarction of an adenoma that has outgrown its blood supply. It is characterized by the acute onset of severe headache that may be retro-orbital, frontal, bitemporal, or generalized ophthalmoplegia; bilateral visual loss; and in severe cases, drowsiness or coma, with either subarachnoid hemorrhage or pleocytosis and elevated protein in the CSF. The CT or MRI shows infarction of tumor, often with hemorrhage in and above an enlarged sella. Pituitary apoplexy may threaten life unless the acute addisonian state is treated by hydrocortisone. Blindness is the other dreaded complication. If there is no improvement after 24 to 48 h, or if vision is markedly affected, transsphenoidal decompression of the sella is indicated. Factors that may precipitate the necrosis or hemorrhage of a pituitary tumor are anticoagulation, pituitary function testing, radiation, bromocriptine treatment, and head trauma; most cases, however, occur spontaneously. Some pituitary adenomas have been cured by this accident.
Ischemic necrosis of the pituitary, without the presence of a tumor followed by hypopituitarism, occurs under a variety of circumstances, the most common being in the partum or postpartum period (Sheehan syndrome).
Meningioma of the Sphenoid Ridge
This tumor, mentioned earlier in the chapter, is situated over the lesser wing of the sphenoid bone. As it grows, it may expand medially to involve structures in the wall of the cavernous sinus, anteriorly into the orbit, or laterally into the temporal bone. Fully 75 percent of such tumors occur in women, and the average age at onset is 50 years. Most prominent among the symptoms are a slowly developing unilateral exophthalmos, slight bulging of the bone in the temporal region, and radiologic evidence of thickening or erosion of the lesser wing of the sphenoid bone. Variants of the clinical syndrome include anosmia; oculomotor palsies; painful ophthalmoplegia (sphenoidal fissure and Tolosa-Hunt syndromes; see Table 44-2); blindness and optic atrophy in one eye, sometimes with papilledema of the other eye (Foster Kennedy syndrome); mental changes; seizures (“uncinate fits”); and increased intracranial pressure. Rarely, a skull bruit can be heard over a highly vascular tumor. Sarcomas arising from skull bones, metastatic carcinoma, orbitoethmoidal osteoma, benign giant cell bone cyst, tumors of the optic nerve, and angiomas of the orbit must be considered in the differential diagnosis. Neuroimaging with contrast provides the definitive diagnosis. The tumor is resectable without further injury to the optic nerve if the bone has not been invaded.
Meningioma of the Olfactory Groove