Comparative analysis of growth hormone-secreting mixed gangliocytomas and pure growth hormone pituitary adenomas

Mixed gangliocytoma-pituitary adenomas (MGPAs) are rare sellar tumors, often presenting with signs and symptoms of acromegaly due to the somatotrophic component. The pathogenesis is not well understood, with few cases reported. We present our institutional experience in surgical management and compare surgical outcomes in growth hormone (GH)-secreting MGPAs and GH-secreting pituitary adenomas (GHPAs).

We retrospectively reviewed demographic and clinical data of adult patients with MGPAs and GHPAs operated at our institution from 2018 to 2024.

Six MGPA patients (3 males, 3 females) and 40 GHPA patients (20 males, 20 females) were included. Mean age was 47 (range 36-65) and 49 years (range 19-76), respectively. Common symptoms in both groups were headaches, acral enlargement, and facial changes. All patients underwent endoscopic endonasal transsphenoidal approach (EETA). Preoperative mean IGF-1 levels were similar. Tumor diameter was larger in MGPA (23 mm vs. 15 mm, p = 0.034). Cavernous sinus invasion Knosp 4 was more common in MGPA (16 %) than GHPA (5 %) (p = 0.121). Hormonal remission, defined as normalized IGF-1 at 3-6 months postoperatively, was achieved in 50 % of MGPA and 48 % of GHPA patients. Mean follow-up time for MGPA and GHPA patients was 19 months and 34 months respectively. Neither group experienced disease recurrence.

MGPA is a rare subtype of pituitary adenoma; however, it represented 12.8 % of operated GH-secreting tumors at our institution. In our series, MGPAs were larger tumors and more likely to invade the cavernous sinus than GHPAs. EETA was safe and effective in both groups, with similar remission rates.