Prolactin-secreting macroadenomas in adolescents. Response to bromocriptine therapy

To report five cases of prolactin (PRL)-secreting macroadenomas in adolescents, including their presentations and responses to bromocriptine mesylate treatment.

Five adolescents (three females and two males) aged between 12.5 and 17 years were diagnosed as having PRL-secreting macroadenomas at the pediatric endocrine service at New York University Medical Center between 1987 and 1989. Presenting complaints included visual field deficits, gynecomastia, and amenorrhea, both primary and secondary. All patients demonstrated some feature of hypogonadism or pubertal arrest. Diagnostic criteria included an elevated serum PRL level (mean, 1670 micrograms/L; range, 610 to 3700 micrograms/L) and visualization of a pituitary tumor that measured greater than 1 cm by either a computed tomographic scan or magnetic resonance imaging (mean size, 2.7 cm; range, 1.4 to 4 cm).

Each patient was treated with bromocriptine mesylate at an oral dose of 7.5 mg/d. The patients continued with that treatment for the duration of the study period.

Anterior pituitary function was evaluated in four of five patients before treatment. All four were growth hormone deficient. Three patients were also gonadotropin deficient. Thyrotropin (thyroid-stimulating hormone) and corticotropin (adrenocorticotropic hormone) deficiencies were demonstrated in three patients who had multiple pituitary deficits. Follow-up testing included serial PRL measurements and radiographic imaging of tumor size. All patients demonstrated a marked decrease in PRL levels, as well as in tumor size (mean shrinkage, 70%). The three patients who initially had visual field deficits showed significant improvement of vision with bromocriptine therapy. Follow-up study of anterior pituitary function showed significant improvement with bromocriptine treatment in three patients.

Bromocriptine was quite effective in the shrinkage of PRL-secreting macroadenomas in all our patients. It is a noninvasive treatment that can preserve and restore vision, as well as pituitary function, which is integral to continued growth and sexual maturation of the adolescent. Bromocriptine is preferable to surgery or radiation in the treatment of PRL-secreting macroadenomas in the adolescent.