Prolactinomen

Prolactinomen is a term occasionally used to refer to a prolactin-secreting pituitary neoplasm. The more widely accepted term is prolactinoma, and it is typically a lactotroph adenoma. Prolactinomas can be microadenomas (less than 10 mm) or macroadenomas (10 mm or larger) and are the most common type of pituitary adenoma.

Pathophysiology and clinical features: Prolactinomas produce excess prolactin, which suppresses the hypothalamic-pituitary-gonadal axis by reducing GnRH secretion. In women, this often causes menstrual disturbance, infertility, and galactorrhea; in men, symptoms may include reduced libido, erectile dysfunction, and sometimes galactorrhea. Large tumors can cause headaches and, if they compress the optic chiasm, visual field defects. The presentation may differ by age and sex, with women more likely to present earlier.

Diagnosis: Evaluation typically includes measuring fasting serum prolactin levels, with confirmation by repeat testing if needed. Pregnancy should be excluded. If hyperprolactinemia is confirmed, MRI of the pituitary is performed to identify a lactotroph adenoma. Additional tests may assess thyroid function, kidney and liver function, and visual fields to evaluate tumor impact.

Treatment and prognosis: First-line therapy is a dopamine agonist, usually cabergoline, or bromocriptine if needed. These drugs lower prolactin levels, shrink the tumor, restore normal menstrual function, and improve fertility in many patients. Radiation therapy or surgical removal via transsphenoidal surgery are considered for resistant cases, intolerance to medications, or significant mass effect. With appropriate treatment, prognosis is generally favorable, though long-term follow-up is required to monitor prolactin levels and tumor size.