Endoscopic endonasal resection of ectopic suprasellar pituitary neuroendocrine tumors: comparison of intra-stalk and extra-stalk tumors. Illustrative cases.

BACKGROUND: Ectopic suprasellar pituitary neuroendocrine tumors (Pit-NETs) are exceptionally rare lesions that differ from intrasellar Pit-NETs in both imaging appearance and surgical management. This paper presents 2 cases of intra-stalk ectopic suprasellar Pit-NETs and 2 cases of extra-stalk ectopic suprasellar Pit-NETs.

OBSERVATIONS: Cases 1 and 2 are ectopic suprasellar Pit-NETs of the intra-stalk type, meaning they originated from and grew within the pituitary stalk. Preoperative imaging revealed an indistinct pituitary stalk. The tumors completely occupied the stalk, compressing it into a thin, attenuated structure, which made it extremely difficult to preserve the integrity of the stalk. In contrast, cases 3 and 4 are ectopic suprasellar Pit-NETs of the extra-stalk type. Although these tumors also originated from the stalk, their growth predominantly occurred outside of it. Preoperative imaging clearly visualized the pituitary stalk in these cases. Despite the compression caused by the tumors, the integrity of the stalk was preserved.

LESSONS: Preservation of stalk integrity is more difficult in intra-stalk than in extra-stalk ectopic suprasellar Pit-NETs. Since the intra-stalk type carries a higher risk of postoperative hypopituitarism, regular follow-up observation is recommended for asymptomatic patients. Given the risk of postoperative hypopituitarism, surgical intervention for the intra-stalk type should be approached with caution. https://thejns.org/doi/10.3171/CASE26198.