[Significance of pseudocapsule in the excision of pituitary adenomas in transsphenoidal surgery].

Objective: To explore the significance of pseudocapsule in the excision of pituitary adenomas in transsphenoidal surgery.

Methods: For 22 patients with pituitary adenomas over a period of 2 years at Peking Union Medical College Hospital, resection of pseudocapsule was applied for complete tumor removal. Pituitary function test and radiological imaging were performed at pre-operation, 3 months post-operation and at subsequent 6-12 months intervals postoperatively.

Results: All pituitary adenomas were totally removed under microscope. The symptoms of headache, disorder of sight and visual field disappeared postoperatively in nonfunctional pituitary adenomas. The GH levels of 2/5 growth hormone secreting adenoma patients were 4.2 and 7.7 µg/L while it was under 1 µg/L for another 3. The postoperative level of prolactin was 4.3 µg/L in prolactin secreting adenoma. The level of adrenocorticotropic hormone decreased under 5 ng/L except one was 15.7 ng/L. Leakage of cerebrospinal fluid occurred intraoperatively in 3 patients and postoperatively in 1. No leakage was found after repair. Diabetes insipidus occurred in one patient and was controlled with Minirin. Pseudocapsule was confirmed by pathological examination. Special staining revealed reticulum fibers in pseudocapsule.

Conclusion: Resection of pseudocapsule may achieve a higher remission rate without deteriorating pituitary function.