medwireNews: A multicentre study of patients with gonadotropin-independent precocious puberty (GIPP) shows that, after excluding patients with congenital adrenal hyperplasia (CAH), the condition predominantly affects girls.

The female predominance was because the two most common aetiologies were functional ovarian cyst and McCune-Albright syndrome (MAS), although the researchers note that these two aetiologies “can exhibit overlapping features”.

The 27 boys in the study had various tumours as the main cause, while two had hypothyroidism and five testotoxicosis.

The 129 patients, 102 of whom were female, excluded those with CAH and were identified from paediatric centres across Turkey. Overall, 37% cases were caused by functional ovarian cyst and 26% by MAS.

All the girls with functional ovarian cyst had single unilateral cysts, but Abdullah Bereket (Marmara University Pendik Research Hospital, Istanbul) and co-researchers say: “It is important to note that solitary ovarian cysts could be a component of MAS”.

This was the case in 12 of their patients, they say. “[T]herefore, evaluation of skin for café-au-lait spots, bone X-rays/scintigraphy, and hormonal profiles for endocrine hyperfunction are necessary before diagnosing functional ovarian cysts.”

The “classic triad” of café-au-lait spots, fibrous dysplasia and GIPP was present in 52.9% of the MAS patients, with 32.3% lacking fibrous dysplasia and 11.7% lacking café-au-lait spots, the team reports in The Journal of Clinical Endocrinology & Metabolism.

Tumours were the next most common cause of GIPP, with adrenocortical tumours accounting for 9% of cases, human chorionic gonadotropin (hCG)-secreting tumours for 5.5%, Leydig cell tumours and ovarian tumours for 4% each, and Sertoli cell tumours for 2%.

Children with adrenocortical tumours tended to present early, at an average age of just 3.4 years for both girls and boys. The research team notes that although high dehydroepiandrosterone levels are a strong indicator of adrenocortical tumours, normal levels “do not completely eliminate the diagnosis”. Indeed, one patient had a level of just 30 µg/dL.

They also highlight that hCG-secreting tumours “produce an anthropometric and hormonal picture similar to that of testotoxicosis.” Patients with these aetiologies had similar testicular volumes and very high testosterone levels, with hCG levels being the differentiating factor between the two groups.

hCG-secreting tumours were most commonly germ-line tumours of the sellar-suprasellar region, but also included one mediastinal tumour, and two hepatic tumours – one choriocarcinoma and also one hepatoblastoma, which “deserves a specific mention”, the researchers say, “as an extragonadal and extra-adrenal malignancy”.

By Eleanor McDermid, Senior medwireNews Reporter

J Clin Endocrinol Metab 2016; Advance online publication

medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016

Free abstract