The pseudocapsule surrounding a pituitary adenoma and its clinical significance.

The transsphenoidal approach is currently considered the preferred first-line treatment for pituitary adenoma. With the discovery and application of the pseudocapsule surrounding a pituitary adenoma, transsphenoidal surgery of pituitary adenoma further falls into two categories: "extracapsular" and traditional "intracapsular" resection methods, on the basis of where dissection is performed with respect to the pseudocapsule. Thus, the pseudocapsule can be used as a plane to guide the operation, helps in total resection of pituitary adenoma, and can guide subsequent treatment after surgery.