PROLACTINOMA ASSOCIATED WITH TRANSIENT GROWTH-HORMONE DEFICIENCY BUT PERSISTENT GROWTH-RETARDATION

A 14.8 year old boy was evaluated for galactorrhea of two months durat ion and growth deceleration for greater than three years. He was 3.7 s tandard deviations (SD) below the mean for age in height and euthyroid with uncompromised vision, bilateral galactorrhea, and pubertal arres t. MRI demonstrated a 10 x 8 mm left pituitary mass. Bone age was 11.5 years. Serum prolactin (PRL) decreased by more than 85% after 5 weeks of treatment with bromocriptine (Br). After five months, the prolacti noma (PRLoma) measured 5 x 4 mm. Hypothalamic-pituitary function indic ated growth hormone (GH) deficiency and hypogonadotropic hypogonadism as assessed by ITT-TRH-GnRH-clonidine. After nine months of Br, despit e return of adequate gonadotropin and GH secretion as assessed by repe at ITT-TRH-GnRH-clonidine, pooled 12 hour nocturnal spontaneous GH sec retion, and clinical progression of puberty, there was no linear ''cat ch-up growth'' (growth rate = 4.4 cm/yr and height 4.2 SD below the me an for age). Growth rate increased following supplemental GH administr ation without untoward effect. We conclude that there may be discordan ce/lag between reduction in secretion and size of PRLomas and growth d espite resolution of other anterior pituitary dysfunction. Other possi bilities are discussed.