A 39-year-old man presents to his physician with the complaint of loss of peripheral vision. The subsequent magnetic resonance imaging (MRI) scan below demonstrates
Cerebral atrophy
Pituitary adenoma
Optic glioma
Pontine hemorrhage
This T1-weighted sagittal MRI scan reveals a dumbbell-shaped homogeneous mass involving the sella turcica and the suprasellar region. This lesion is most consistent with a pituitary adenoma, a benign tumor arising from the adenohypophysis. Pituitary adenomas are the most common sellar lesion and constitute 10-15% of all intracranial neoplasms. Macroadenomas (>10 mm) are generally non secreting tumors. Microadenomas (<10 mm) become clinically apparent from hormonal secretion. They may secrete prolactin (amenorrhea or galactorrhea), growth hormone (gigantism or acromegaly), or ACTH (Cushing syndrome). The tumor pictured is a macroadenoma. Its dumbbell shape results from impingement on the adenoma by the diaphragm of the sella turcica. The suprasellar extension seen here makes a frontal craniotomy rather than a transsphenoidal approach more appropriate.
Nervous System