Endoscopic endonasal resection of nonfunctioning pituitary adenoma with radiological calcification

Objective: Radiological calcification in nonfunctioning pituitary adenoma is scarcely rare, which appears in various formations and raises special diagnostic and therapeutic challenges. Here we present our experience about the clinical aspects and treatment of calcified nonfunctioning pituitary adenoma.

Methods: A total of 145 patients who underwent surgical resection of nonfunctioning pituitary adenomas via endoscopic endonasal approach from February 2008 to December 2018 were reviewed. Among these patients, cases with radiological calcifications on preoperative imaging were included in this study. We analyzed these patients' records, radiological neuroimaging, endocrine evaluation, operative notes as well as intraoperative videos.

Results: Calcification on preoperative neuroimaging was observed in only 7 patients with nonfunctioning pituitary adenomas. The study population consisted of these seven patients with intra-tumor calcification (n = 2), thin and egg shelf-like capsular calcification (n = 3), hard and armor-like capsular calcification (n = 2). In 85.7% of cases (n = 6), nonfunctioning pituitary adenomas with calcification were characterized by soft tumor texture. Evidences demonstrated apoplexy occurred in 71.4% of cases with calcified pituitary adenomas (n = 5). Patients with intra-tumor calcification as well as with thin and egg shelf-like capsular calcification underwent resection of both tumor and calcification through extra-pseduocapusual dissection via endoscopic endonasal approach. Besides, in the remaining 2 cases (28.6%), hard and armor-like capsular calcification was found surrounding a soft tumor component; however, it did not interfere with adequate removal of the soft part via endoscopic endonasal approach with the hard calcification untouched. Postoperative course of all patients was uneventful. Long term follow-up (median interval of 49 months, range 8-70 months) showed that no recurrence occurred.

Conclusions: Although relatively rare, calcified nonfunctioning pituitary adenoma should be kept in mind to avoid making a wrong preoperative diagnosis. Given various calcification types, multiple surgical tactics is required accordingly. Extra-pseudocapusual resection via endoscopic endonasal approach is helpful for the resection of both adenoma and calcification.