An 18-year-old with anterior pituitary adenoma would most likely present with which sign?

• A. Cessation of menses
• B. Milk production
• C. Excessive urine output
• D. Weight gain

Answer: (A)

An elevated prolactin level from a prolactin-secreting pituitary adenoma suppresses the hypothalamic release of GnRH. With less GnRH, the pituitary reduces LH and FSH, so ovarian stimulation and ovulation fall, leading to amenorrhea. In an 18-year-old female, stopping menses is a classic presenting sign of hyperprolactinemia from an anterior pituitary tumor. Milk production can occur with high prolactin, but amenorrhea is the most common and emphasized clinical feature in this scenario. Excessive urine output would suggest diabetes insipidus (posterior pituitary issue), not typical of an anterior pituitary adenoma, and weight gain is not a characteristic hallmark of a prolactin-secreting tumor.