Abstract and Introduction
Abstract
Gonadotropin-releasing hormone analogues (GnRHas) are an effective treatment to address the compromise in height potential seen in patients with central precocious puberty. There is no evidence in the literature of a single GnRHa used for longer than 2 years before being removed or replaced. We describe a patient who was on continuous gonadotropin suppression for 7 years and despite this, achieved a height potential within 1 SD of mid-parental height. A boy aged 10 years 3 months presented to the endocrine clinic with signs of precocious puberty and advanced bone age. Initial laboratory values were a random luteinizing hormone (LH) level of 9.4 mIU/mL, follicle-stimulating hormone (FSH) 16.3 mIU/mL, dehydroepiandrosterone sulfate 127 mcg/dL, and testosterone 628 ng/dL. The patient was initially started on Lupron injections before transitioning to a histrelin implant. Follow-up laboratory results 5 months post-suppression showed pre-pubertal random LH 0.2 mIU/mL, FSH 0.1 mIU/mL, and testosterone 5 ng/dL. The patient was lost to follow-up and returned 5 years later presenting with gynecomastia and delayed bone age. He had continuous gonadotropin suppression with random LH 0.10 mIU/mL, FSH 0.16 mIU/mL, and testosterone 8 ng/dL. The histrelin implant was removed, and 4 months later, his random pubertal hormone levels were LH 5.6 mIU/mL, FSH 4.3 mIU/mL, and testosterone 506 ng/dL. The patient's mid-parental height was 175.3 cm and his near final height was 170.6 cm, which is within 1 SD of his genetic potential. Further studies are needed to explore continuous gonadotropin hormone suppression with a single histrelin implant beyond 2 years.
Introduction
Central precocious puberty (CPP) is defined as thelarche prior to the age of 8 years in females and testicular enlargement prior to age of 9 years in males.[1] A hallmark characteristic of CPP is bone age acceleration leading to early epiphyseal fusion of the growth plates.[2] Gonadotropin-releasing hormone analogues (GnRHas) are the mainstay of therapy to prevent compromise in growth potential by slowing down bone age maturation. Histrelin implant is a nonbiodegradable device inserted within the subcutaneous tissue that provides systemic distribution of the analogue.[3] The histrelin implant suppresses clinical and laboratory parameters of puberty over 1 year, providing an alternative to monthly GnRHa injections.[4] Six months after removal of the implant there is a return to pubertal levels of FSH and LH after discontinuation of long-term gonadotropin suppression.[2] A single histrelin implant has been reported to be effective for up to 24 months.[5] There is no evidence in the literature of a single histrelin implant being effective beyond 2 years. We describe a novel case of a histrelin implant for treatment of CPP showing continuous hormonal suppression 7 years after implantation.
J Endo Soc. 2022;6(2) © 2022 Endocrine Society
