Preoperative and Postoperative Pituitary Function in Patients with Tuberculum Sellae Meningioma -Based on Pituitary Provocation Tests-

Given the anatomical proximity of tuberculum sellae meningioma (TSM) to the hypothalamo-pituitary system, pituitary function impairments are of great concern. We retrospectively investigated pituitary function changes following surgery in patients with TSM using pituitary provocation tests (PPTs). Thirty-one patients (27 females and 4 males) with TSM underwent initial transcranial surgery (29 patients) or transsphenoidal surgery (two patients); surgeries were performed carefully to avoid injuring the pituitary stalk. In 24 patients, the PPTs were performed via a triple bolus injection with regular insulin, thyrotropin-releasing hormone (TRH), and luteinizing hormone releasing hormone (LH-RH). Seven patients underwent a quadruple test (growth-hormone-releasing factor, corticotrophin-releasing hormone, TRH, and LH-RH). The preoperative and postoperative target hormone levels of the anterior pituitary were normal in 93.5% and 96.8% of patients, respectively. At least one hormonal axis demonstrated impaired PPT responses in two patients (6.5%) preoperatively and in one patient (3.2%) postoperatively. The growth hormone (GH) response was also well preserved. A compromised GH peak level was only observed in one patient (3.2%) preoperatively. Postoperatively, transient diabetes insipidus and transient hyponatremia were observed in four (12.9%) and eight (25.8%) patients, respectively. No patients needed permanent postoperative hormone replacement. The preoperative pituitary function was well preserved in most patients, including those with large tumors pushing against the pituitary stalk considerably or embedded in it. After careful surgery to avoid damaging the pituitary stalk, pituitary function was preserved. However, transient postoperative hyponatremia occurred in 25.8% of patients; thus, surgeons should pay careful attention to this issue.