A 35-year-old woman complains of nipple discharge and irregular menses of 5 months duration. Physical examination reveals a milky discharge from both nipples. MRI shows an enlargement of the anterior pituitary. Which of the following is the most likely histologic diagnosis of this patient's pituitary tumor?: (A) Adenoma, (B) Choriostoma, (C) Hamaoma, (D) Papilloma
Answer is A. Benign tumors arising from a glandular epithelium are termed adenomas. Patients with a prolactin-secreting pituitary adenoma present with amenorrhea and galactorrhea Ectopic islands of normal tissue are called choristomas (choice B) Localized, disordered differentiation during development results in a hamaoma (choice C). Papillomas do not occur in the pituitary (choice D).