Endocrine Abstracts

Introduction: The use of GH treatment in patients with macroadenomas and GH deficiency is of concern to the clinician due to the theoretical stimulation of tumor regrowth by GH substitution. We report the case of an 18-year-old adolescent with a macroprolactinoma causing delayed stature and puberty.

Observation : We report the case of an 18-year-oldadolescent who consulted for gynecomastia with delayed stature and puberty. Physical examination displayed a statural delay of -3 standard derivation with a statural age of15 years. He had also pubertal delay and gynecomastia with Tanner stage of G2P2A1 The bone age was 13 years and six months according to the Greulich and Pyle method. The hormonal investigation showed markedly elevated plasma prolactine level of 4279mui/l. The evaluation of the other pituitary axes showed a normal thyroid function test. Therefore, it revealed a gonadotropic insufficiency (testosterone=3.2mmol/l FSH=3.28mui/ml LH=1.23mui/ml) and a complete GH deficiency confirmed by 2 stimulation tests (insulin hypoglycemia test and clonidine test). The diagnosis of a macroprolactinoma was retained based on tumoral level of prolactinemia and pituitary magnetic resonance imaging revealing a pituitary macroadenoma of 10 mm long axis. The patient was put on a dopaminergic agonist: cabergoline 1.5 mg per week with good clinical and hormonal evolution. However, the difficulty was to substitute GH deficiency for fear of progression of the tumorous mass. It is the common opinion that GH substitution should not be consistently started in patients with macroprolactinoma for the reason that spontaneous recovery of hypothalamic pituitary function which has been inhibited by high PRL levels. But given the bone age limit and the non-promiscuity of the tumor and the optic chiasma, the decision was to initiate a recombinant GH treatment. The evolution was characterized by a good clinical response (gain of 11 cm in 9 months), without showing signs of tumor progression.

Discussion: In the literature, rare cases of combined treatment (dopaminergic agonist and somatotropin) have been reported but the treatment appeared to be effective in restoring growth velocity, also it seems to be safe as it did not show any progress on tumor growth. However, limited experience with the use of such combined therapy in children and adolescents warrants careful monitoring and on-going evaluation.