Clinical characteristics and pathological features of growth hormone-secreting pituitary adenoma combined with hyperprolactinemia.

PURPOSE

Large-scale reports on growth hormone-secreting pituitary adenomas (GHPA) with hyperprolactinemia (HPRL) remain limited. The relationship between clinical characteristics and pathological subtypes of GHPA patients, based on the 2022 classification of pituitary neuroendocrine tumors (PitNET), has rarely been elucidated. This study aims to enhance the understanding of clinicopathological features in GHPA and clarify differences between patients with and without HPRL.

METHODS

We retrospectively collected the clinical data of 810 patients diagnosed with GHPA. The clinical and pathological characteristics were compared between the HPRL and non-HPRL groups. Patients were categorized according to 2022 pathological classification and their differences were compared.

RESULTS

Compared to the non-HPRL group, the HPRL group exhibited more visual acuity/field impairment and galactorrhea and had higher GH levels. The tumor volume (TV) in the HPRL group was significantly larger, with more severe cavernous sinus invasion and optic chiasm compression, and a higher proportion of mammosomatotroph PitNETs. The most common pathological types of GHPA included sparsely granulated somatotroph PitNETs (46.19%), mammosomatotroph PitNETs (17.37%), and plurihormonal PitNETs (17.80%). Patients with immature PIT-1 lineage PitNETs had the lowest biochemical remission rate and highest tumor residual/recurrence rate.

CONCLUSION

The symptoms of galactorrhea and visual acuity/field impairment contribute to early diagnosis in GHPA patients with HPRL. Although TV is larger and invasiveness is greater, HPRL does not significantly affect the biochemical remission rate. Nearly half of GHPA cases are sparsely granulated somatotroph PitNETs, which are often associated with poor tumor outcomes, highlighting the critical role of pathological type in predicting clinical prognosis.