Objective: The long-term results of transsphenoidal surgery for microprolactinoma, with particular reference to the question of permanence of relapse of hyperprolactinemia after biochemical cure, are examined.
Methods: Patients whose operations were performed in the city of Glasgow, Scotland, by one neurosurgeon (GMT) have been followed up for between 15 and 21 years after surgery was performed.
Results: Of a cohort of 44 patients with confirmed microprolactinoma at the time of surgery, 8 patients (18.2%) who experienced recurrent hyperprolactinemia postoperatively continued to be monitored. Selective hypophysectomy resulted in normal prolactin levels in all patients initially. Relapse occurred at 2 to 10 years (mean, 5.3 yr) postoperatively, but was permanent in only two patients (4.5%). Of the remaining six patients (13.6%), four (9.1%) became normoprolactinemic after 6 or 7 years' recurrence, and two (4.5%) are now only marginally hyperprolactinemic (prolactin >500 but <700 mU/L) at 15 and 18 years after transsphenoidal hypophysectomy.
Conclusion: The recurrence of hyperprolactinemia after transsphenoidal surgery for microprolactinoma is not necessarily a permanent feature and does not inevitably indicate operative failure.