Endocrine Abstracts

JOINT2745

Introduction: Acromegaly is a rare condition predominantly caused by a growth hormone (GH)-secreting pituitary adenoma driving excess secretion of insulin-like growth factor-1 (IGF-1). Multitude of manifestations have been associated with chronic GH excess, including cardiovascular, pulmonary, neoplastic, endocrine, metabolic and musculoskeletal comorbidities. The diagnosis of acromegaly is confirmed on biochemical grounds. Pituitary magnetic resonance imaging is advised in patients to identify an underlying pituitary adenoma. Transsphenoidal pituitary surgery is generally first-line therapy for patients with acromegaly. Medical therapies can be recommended to patients with persistent disease. Radiation therapy is usually a third-line option.

Case Report: We present a case of 33 y/o female first diagnosed with pituitary macroadenoma, hyperprolactinemia at the age of 20. Additional pituitary hormonal work-up was not performed at that time. Treatment with dopamine agonist (cabergoline) was initiated. 5 years after diagnosis, patient was evaluated by another endocrinologist due to increasing headaches, lightheadedness, acral and facial features of acromegaly (skin thickening, changes to facial symmetry, increased shoe size). Head MRI and additional laboratory work-up revealed growth of pituitary adenoma and increased levels of IGF-1. Patient was diagnosed with acromegaly and transsphenoidal surgery was performed which led to slightly decreased levels of IGF-1. Repeated MRI scan performed a year later, revealed residual tissue. Repeat TSS was performed in Germany a year later due to residual intrasellar disease following initial surgery. IGF-1 levels normalized after surgery and patient was being monitored. Elevated IGF-1 levels were not demonstrated until 2022. Patient was advised to initiate treatment with somatostatin analogs, which she declined, alternatively, due to modest elevations of serum IGF-1 and mild signs and symptoms of GH excess, off label use of dopamine agonist –cabergoline was offered. Most recent MRI does not show evidence of residual tissue. Patient continues DA therapy, currently her IGF-1 levels are well under control. Patient is being counseled and monitored for recurrence and associated comorbidities.

Conclusion: A high index of suspicion is needed to minimize delays in diagnosis of acromegaly. Goals of treatment include normalization of GH secretion or (at least) GH action as indicated by a normal IGF-1 level as well as by resolution of tumor-induced mass effects, acromegaly-related symptoms, and associated comorbidities, all aiming at mitigating excess mortality while preserving normal pituitary function.

References: 1. Ershadinia N, Tritos NA. Diagnosis and Treatment of Acromegaly: An Update. Mayo Clin Proc. 2022 Feb;97(2):333-346. doi: 10.1016/j.mayocp.2021.11.007. PMID: 35120696.