Resolution of Hyperprolactinemia Caused by Pituitary Stalk Compression After Transsphenoidal Surgery for Pituitary Tumors.

BACKGROUND: Hyperprolactinemia caused by pituitary stalk compression is common in patients with pituitary tumors. There is a lack of studies investigating the resolution patterns or time course of hyperprolactinemia after surgery. We aimed to demonstrate the time course of changes in prolactin levels following successful surgical decompression of the pituitary stalk. METHODS: We retrospectively examined 201 patients with preoperative hyperprolactinemia caused by the pituitary stalk compression effect who underwent transsphenoidal surgery. Postoperative prolactin levels were assessed at the time points of 1 week; 1, 3, and 6 months; and 1 year following the surgery. As a subgroup analysis, 115 individuals underwent serial prolactin level measurements at 6, 12, 18, 24, 48, and 72 hours after surgery. RESULTS: Hyperprolactinemia caused by pituitary stalk compression was resolved in 71.64% of patients 1 week after surgery, 84.84% after 1 month, 89.30% after 3 months, and 92.67% after 6 months, and 92.74% eventually reached normalization 1 year after surgery. Among the 35 patients whose prolactin levels were measured in the immediate postoperative period, 26 patients (72.49%) reached remission status within 72 hours. The immediate postoperative prolactin level was most predictive at 72 hours after surgery, with an optimal cutoff of 23.10 ng/mL. CONCLUSION: The postoperative resolution of hyperprolactinemia caused by stalk compression was possible in 90% within a year. The decline in serum prolactin levels typically began within the first 72 hours after surgery, indicating that the hormonal response to surgical decompression is very prompt and effective.