Hypopituitarism patterns among adult males with prolactinomas

•A large cohort of male patients with prolactinomas were studied.•A larger cohort may have led to more statistically significant results in the study.•Recovery from visual field defects and hypopituitarism was noted in most of the patients.•Our study provides better insight into hypopituitarism patterns in these patients.•The adenoma size is correlated with the prevalence of pituitary hormone dysfunction. The objective of this study was to characterize hypopituitarism in adult males with prolactinomas. We retrospectively analyzed the records of 102 consecutive patients, classified under three categories based on adenoma size at diagnosis: 1.0–2.0cm (group A), 2.1–4.0cm (group B), and >4.0cm (group C). Further, 76 patients had successful outcomes at follow-up. We compared different forms of pituitary hormone dysfunction (growth hormone deficiency, hypogonadism, hypothyroidism, and hypocortisolism) based on the maximal adenoma diameter. Serum prolactin levels were significantly correlated with the maximal adenoma diameter (r=0.867; P=0.000). Of the patients, 89.2% presented with pituitary failure, which included 74.5% with growth hormone deficiency, 71.6% with hypogonadism, 28.4% with hypothyroidism, and 12.7% with hypocortisolism. The three groups did not differ significantly (P>0.05) in the incidence of hypopituitarism, including the extent of pituitary axis deficiency, at presentation and following treatment. However, there was a statistically significant difference in the degree of hypogonadism in cases of acquired pituitary insufficiency at diagnosis (P=0.000). In adult males with prolactin-secreting adenomas, the most common form of pituitary hormone dysfunction was growth hormone deficiency and hypogonadism, whereas hypocortisolism was less common. The maximal adenoma diameter and prolactin secretion did not determine hormone insufficiency in adult males with prolactinomas, but these factors did affect the degree of both hypogonadism and hypothyroidism. Smaller tumors were found to recur more frequently than large tumors, and recovery was more common in cases of growth hormone deficiency and hypogonadism.