SUBCLINICAL ACROMEGALY DUE TO A PITUITARY CYSTIC SOMATOTROPH ADENOMA

Incidentally detected acromegaly: single-center study of surgically treated patients over 22 years

Acromegaly is a rare disease associated with comorbidities that are common in the general population. Most patients undergo screening for classic phenotypical (CP) or mass effect manifestations. By retrospective review of pituitary tumor surgeries performed between 1994 and 2016 (1836), we identified patients with acromegaly (112). Main presentations were: CP (43%), mass effect (26%), incidentally detected (ID) tumors (17%), and other (14%). We compared the ID and CP groups regarding prevalence, clinical, biochemical, radiological and histopathological characteristics, and postoperative outcomes. The prevalence of ID among all surgeries increased after 2011 from 0.6% to 1.9% (p=0.01), while prevalence of CP remained stable (2.8% and 2.33%, p=0.65). Almost half of ID (47.4%) presented with otolaryngological manifestations. The ID and CP groups were similar regarding age, gender, comorbidities (hypertension, diabetes, hypopituitarism), tumor diameter and cavernous sinus invasion. Median insulin-like growth factor (IGF-1) and growth hormone (GH) levels were lower in the ID than CP (p<0.05 and p=0.07). Patients younger than 40 had smaller tumors in the ID than CP, while the opposite was true for older patients. The 3-month biochemical remission rates were similar (68% ID and 58% CP). A similar number of patients had normal IGF-1 at last follow-up (89.5% ID and 81.25% CP) after surgery alone and multimodality treatment. In conclusion, an increased number of patients with GH-secreting adenomas were ID in recent years. Education of physicians other than endocrinologists regarding presentation and comorbidity clustering may lead to an earlier diagnosis of acromegaly and improved outcomes.