Pituitary Adenoma Confined Within the Pituitary Stalk: A Case Report and Literature Review

Pituitary adenomas are among the most common intracranial tumors, accounting for 10–15% of all intracranial tumors. Nonfunctioning pituitary adenomas require surgical management when they are expected to show symptoms attributed to mass effect. The majority of pituitary adenomas originate from the anterior pituitary gland; that is, majority of pituitary adenomas grow within the sella turcica. Furthermore, pituitary adenomas may dilate the diaphragm and extend beyond the suprasellar area. On rare occasions, they may be present in extra-sellar sites not continuous with the pituitary gland, with or without an adenoma in the pituitary gland. First described by Erdheim in 1909 and predominantly described in case reports, such cases may be referred to as ectopic pituitary adenomas (EPAs). Though most pituitary adenomas are found in continuity with the gland, such ectopic forms of pituitary adenomas are usually Pituitary adenomas within the pituitary stalk, without pituitary gland involvement, are extremely rare. To date, only six cases of pituitary adenomas confined to the pituitary stalk have been reported in English publications; all of which were functional tumors suspected to originate from the pars tuberalis. Herein, we report a case of a non-functioning pituitary adenoma thought to originate from and confined within the pituitary stalk. The patients had normal hormone levels during the initial evaluation and underwent surgery using the endonasal trans-sphenoidal approach. Histopathological examination was performed to confirm the diagnosis. A careful review of the literature was also performed.