Background: Suprasellar pituitary adenomas (SPAs) are a special type of pituitary adenoma. Although dozens of SPA cases have been reported, the exact definition and the characteristics of SPA have not been exhaustively discussed before.
Methods: In a retrospective electronic medical records review, 13 patients with SPA were identified in our hospital between January 2010 and December 2019. A literature review was performed by searching the online database PubMed, and 39 cases conformed to the criteria based on the previous literature. Data regarding clinical symptoms, imaging manifestations, surgical information and follow-ups were analyzed.
Results: The mean age at diagnosis of 52 patients with SPA was 36.73 years, and most of the patients were female (61.5%). The most common hormone-secreting subtypes of SPA were nonfunctioning (36.5%) and ACTH-secreting (34.6%) SPA. Macroadenomas (68.9%) were more common than microadenomas (31.1%). The origins of the SPAs included the intrasellar pituitary gland (type I), the subdiaphragmatic (type IIa) and supradiaphragmatic (type IIb) part of the pituitary stalk, and the suprasellar peri-infundibular region (type III). The most common anatomic subtype of SPA was type III, and type IIb was also common. The most common presentations of SPA were visual symptoms, especially for type III SPA. In addition, 64.7% and 73.1% of type IIb and III SPAs, respectively, were suspected to be of suprasellar origin based on presurgical imaging examination. Patients with tumors of suspected suprasellar origin were more likely to receive transcranial surgery (TCS) initially than those with tumors of suspected intrasellar origin (70.6% vs. 22.2%, p = 0.0013). The intact rate for the pituitary stalk after surgery for type II SPA was lower than that for type I and III SPA (52.6% vs. 92.6%, p = 0.0036). More patients with type II SPA experienced postoperative central diabetes insipidus (CDI) than those with type I and III SPA (57.9% vs. 11.1%, p = 0.0011). There was no significant difference in the incidence of postoperative CDI between transsphenoidal surgery (TSS) and TCS (p = 0.1304). Nine patients in our hospital received extended endoscopic TSS; only one experienced tumor recurrence, and no severe complications occurred after surgery.
Conclusions: SPAs could be defined as pituitary adenomas completely or partially located in the suprasellar region. There were both similarities and differences among the different anatomic subtypes of SPA. For patients who were suspected of having SPAs, visual field tests, pituitary hormone evaluation and MRI were necessary. Because imaging examination is not a reliable method, surgery is the only way to confirm the tumor origin. Extended endoscopic TSS might be a safe and efficient approach to remove these tumors, but more studies are needed to verify this conclusion. For type II SPA, the pituitary stalk should be carefully protected during surgery, and postoperative CDI should be monitored.
Keywords: Anatomic origin; Ectopic; Suprasellar; Suprasellar pituitary adenoma.