Endocrine Abstracts

Macroprolactinemia is reportedly 10–25% in patients with hyperprolactinemia (1). Prolactin plays a major role in breast development (2). Macromastia, gigantomastia, breast hypertrophy are used interchangeably (3). Most authors conclude that gigantomastia cannot be treated medically and only resolves with surgical manoeuvres (4). We report a case with gigantomastia diagnosed with macroprolactinemia and treated with cabergolin.

Case: A 44-year-old woman admitted to our clinic with 6 months history of breast enlargement, nipple discharge, mastalgia, and back pain. She requested surgical reduction. Her menstrual cycles were regular. There was no history of chronic disease or drug use. The breasts are firm to palpation and diffusely tender. The superficial veins are prominent and dilated. She had no fever, erythema, ulceration of the breast skin. Breast circumference was 116 cm. Galactorrhea was present. Hormonal assay revealed hyperprolactinemia (prl:87 ng/ml) and macroprolactinemia. Other anterior pituitary hormons were normal. Hook effect was not detected. MRI showed 6 mm pituitary adenoma. Breast ultrasound and mammography were normal. Cabergoline 0.5 mg/week was started. Macroprolactinemia and hyperprolactinemia were normalized within 1 month. 1 and 2 months later, breast circumferences were 110 and 108 cm respectively, although galactorrhea continued. Patient was satisfied with postmedical recovery and gave up operation demand.

Conclusion: Smaller proportion of patients with macroprolactinemia has signs and symptoms of hyperprolactinemia; galactorrhea is present in 20%, oligo/amenorrhea in 45%, and pituitary adenomas in 20% (5). Two explanations are possible in our case: coexistence of pituitary adenoma and macroprolactinemia or macroprolactin production by pituitary tumor itself. Literature data have provided evidence in favor of both possibilities (6). Cabergolin treatment seems to be safe and effective in controlling gigantomastia and macroprolactinemia without surgical intervention. Although macroprolactinemia is considered to be a benign condition, pituitary imaging, dopamine agonist treatment, and prolonged follow-up should be recommended in some cases (6).