Endocrine Abstracts

A 5.65-year-old boy was referred with a 2-month history of accelerated growth and pubic hair development. Weight and height were >98th C. Pubertal assessment was G3 PH2 AH1 TV 5 ml/4 ml. There was no family history of precocious puberty. No birthmarks, or abdominal masses were present. Blood pressure was normal. Investigations revealed elevated testosterone (7.1 nmol/l), suppressed gonadotropins (LH <0.2 IU/l), normal 17-OHP, androstenedione and DHEAS, prepubertal LHRH test and advanced bone age, consistent with a diagnosis of gonadotropin-independent precocious puberty (GIPP). Further investigations revealed elevated serum HCG (11.1 (0–5)), normal AFP, normal ultrasound testes and abdomen, chest X-ray, MRI pituitary, and normal sequencing of LH receptor gene. Bone scan did not identify any abnormal uptake suggestive of fibrous dysplasia.

Treatment with cyproterone acetate was complicated by adrenal insufficiency that required hydrocortisone replacement. At 6.5 years, there was evidence of gonadotropin-dependent precocious puberty and decapeptyl was added. At 7 years of age, treatment was changed to anastrazole (aromatase inhibitor) and bicalutamide (androgen receptor antagonist) due to no clinical or biochemical improvement.

Serum HCG remained elevated on serial monitoring. CSF HCG was measured, which was elevated and CSF/blood HCG ratio was suggestive of local production. Repeat MRI brain and MRI mediastinum was normal.

At age 8.9 years, the HCG and testosterone levels spontaneously returned to normal. The height velocity slowed down. There was no bone age advancement after the initiation of anastrazole. Adrenal function recovered gradually after the discontinuation of cyproterone.

At last clinic review (12.02 years), there was no bone age advancement, serum HCG remained normal and treatment was discontinued. Given the initial persistently elevated HCG, we speculate that GIPP was secondary to an HCG producing tumour that spontaneously resolved.