A single-center prospective study evaluating the relationship of tumor consistency on remission in acromegaly patients.

The nature of somatotroph adenomas has not been clearly revealed in studies. We consider that there are macroscopic differences in intraoperative tumor consistency in acromegaly patients. We aimed to determine whether there is a relationship between intraoperative tumor consistency and histopathological subtypes by planning a prospective study to determine whether these differences are significant. Between August 1997 and December 2021, 1118 patients with GH-secreting tumors underwent endoscopic endonasal surgery at our Pituitary Research Center. Between January 2022 and May 2023, pure GH-secreting adenomas operated via the endoscopic endonasal approach were sequentially categorized into three types(Type-1:Soft, Type-2:Mucinous/Adhesive, Type-3:Mix/Intermediate) according to the intraoperative tumor consistency. The final patient cohort consisted 218 cases. The ratio of densely granulated adenomas(DG-A) to sparsely granulated adenomas(SG-A) was as follows: Type-1, 89/11; Type-2, 5/95; Type-3, 13/5. Logistic regression revealed that Type-1 tumors were associated with a high remission rate(p = 0.011), and Type-2 were associated with SG-A(p < 0.001). Furthermore, no or weak staining for E-cadherin was associated with Type-2 tumors(p < 0.001). Surgeon could predict the prognosis and histopathological subtype of the pure somatotroph adenoma by observing the intraoperative tumor consistency. This could facilitate better intraoperative planning of patient-specific surgical strategies to increase the remission rates.