Growth hormone excess with onset in adolescence: clinical appearance and long-term treatment outcome

BACKGROUND: Limited data are available on clinical presentation and treatment strategy in patients with GH-secreting adenomas with onset in adolescence. OBJECTIVE: To report results of diagnosis and treatment in adolescents with GH and IGF-I excess. DESIGN: Analytical, observational, retrospective. SUBJECTS: Thirteen patients (five females and eight males, age 15-20 years) all with macroadenoma (two extrasellar, 11 invasive). MAIN OUTCOME MEASURES: Height, body mass index (BMI), GH and IGF-I levels, tumour volume at diagnosis and after treatment. INTERVENTIONS: Transsphenoidal surgery, octreotide subcutaneous (OCT, 0.3-0.8 mg/day), octreotide-LAR i.m. (LAR, 20-30 mg/q28 days), lanreotide i.m. (LAN, 60-90 mg/q28 days), bromocriptine (BRC, 5 mg/day), cabergoline (CAB, 1-2 mg/week). RESULTS: Concomitant hyperprolactinaemia was found in eight patients (61.5%). All girls presented with amenorrhoea, which was associated with galactorrhoea in two patients; all boys presented with symptoms of tumour mass compression such as visual disturbance or headache; two girls also had these symptoms. Height at diagnosis was above the 97th centile in four of five girls and in six of eight boys. None of the patients had altered lipid profile while homeostasis model assessment of insulin resistance (HOMA-IR; 2.8 +/- 0.9) and beta-cell function (HOMA-beta, 207.6 +/- 98.1%) were higher than predicted (1% and 100%, respectively). First-line treatment was surgery in two patients and somatostatin analogues associated with dopaminergic drugs in 11 patients. None of the patients operated on were cured while six of 11 patients receiving pharmacotherapy (6-24 months) were controlled. In these six, tumour volume was reduced by 51.0 +/- 25.2% (median 51.5%). As second-line treatment, all the 11 patients treated with somatostatin analogues underwent surgical removal of their tumours. Surgery was successful in four patients and second-line pharmacotherapy in six patients. One patient was lost at follow-up and two patients maintained active acromegaly despite different treatment schedules; both patients were then treated with radiotherapy. At the last follow-up, there was a significant decrease in insulin levels, HOMA-IR and HOMA-beta without any change in lipid profile. CONCLUSIONS: The clinical presentation of GH-secreting adenomas in adolescent girls is associated with menstrual disturbances and in boys with symptoms of mass effects; tall stature is characteristic in both. First-line treatment with depot somatostatin analogues followed by surgery and then by a second course of somatostatin analogues was successful and safe in 11 of 13 patients.