Endocrine Abstracts

JOINT2244

Hypothalamic hamartoma (HH) is a rare, congenital, and benign lesion often arising from the floor of the hypothalamus involving either tuber cinereum or mammillary bodies and its prevalence varies between 1/50,000 and 1/200,000 persons. The classical signs are: central precocious puberty (CPP), gelastic seizure, and developmental delay. It is usually diagnosed by brain magnetic resonance imaging (MRI) scans and is seen as non-enhancing, isointense, or hyperintense lesions on T2-weighted images. HH is one of the most common organic causes of CPP that tends to occur significantly earlier than idiopathic CPP but it is well managed by gonadotropin releasing hormone (GnRH) agonist. We present the case of a female child who was referred to our Unit of Pediatric Endocrinology for premature thelarche. She was 3 years-old, and on physical examination showed: height 106.7 cm (+ 3.0 SDS), mid-parental height 163.0 cm (0.1 SDS), weight 24.5 kg (+ 3.7 SDS), Tanner stage B2-3, P1, no dysmorphic features. Diagnostic work-up showed: bone age 7.9 yrs (Greulich-Pyle), basal FSH 14.2 mIU/ml, basal LH 8.2 mIU/ml, estradiol 29.7 pg/ml, LH peak of GnRH-stimulation test 29.1 mIU/ml, IGF-1 262 ng/ml, beta-HCG and alfa-fetoprotein negative, pelvic ultrasound (peripubertal uterus with longitudinal diameter 36.9 mm and large ovaries > 3 cc with follicles). Brain MRI scans evidenced a neoformation of oval morphology and dimensions of approximately 9 × 12 × 10 mm, inseparable from the middle third of the hypothalamic infundibulum, with a median location, and projecting into the context of the suprasellar cisterns; the finding was compatible with hamartoma of the tuber cinereum. The adenohypophysis had maximum dimensions of approximately 15x4x4 mm. There were no appreciable signal alterations of the gland in both conditions baseline and after gadolinium administration. Pituitary peduncle was aligned. Since the child had never presented seizures and no indication were for surgical intervention we prescribed medical treatment with Leuprorelin (3.75 mg every 28 days intramuscularly). Six months after starting therapy the child had never experienced any side effects and thelarche had regressed. Our case confirms that children with very early presenting CPP deserve a brain MRI because the risk of an organic lesion is very high. We believe that tall stature should be considered a clue element to differentiate isolated premature thelarche and precocious puberty and when bone age is significantly accelerated, it is mandatory to carry out all the appropriate investigations for the correct diagnosis.