Pituitary Adenoma

Pituitary adenomas are tumors of the anterior pituitary, most of which are indolent and benign. They are classified based on size or cell of origin. Based on size, pituitary adenomas are categorized as microadenomas (<10 mm), macroadenomas (≥10 mm), and giant adenomas (>40 mm). Functionally, they may be divided into hormone-secreting (functional) adenomas, which produce excess amounts of one or more anterior pituitary hormones, and nonfunctional adenomas, which do not secrete biologically active hormones. Nonfunctioning tumors can cause symptoms through mass effect, including compression of normal pituitary tissue or surrounding structures, leading to hormone deficiencies or visual impairment. Evaluation and management of pituitary adenomas typically require an interdisciplinary team involving endocrinologists, neurosurgeons, ophthalmologists, and radiation specialists when indicated.