Van WykeGrumbach Syndrome and Pituitary Hyperplasia in a Six-Year-Old Girl

Abstract

Hypothyroidism is usually associated with delayed puberty and occasionally may present with isosexual precocious puberty. In girls, this may present with breast development, multicystic ovaries and vaginal bleeding. This entity characterized by ovarian hyper stimulation leading to early puberty secondary to hypothyroidism is known as Van WykeGrumbach syndrome. In contrast to the early puberty caused by other causes, precocious puberty of hypothyroidism is characterized by short stature and delayed bone age. Awareness about this condition and the treatment of this condition with levothyroxine will lead to avoidance of surgery and unnecessary intervention. We present the case of a six-year-old girl who presented with precocious puberty and pituitary hyperplasia. This case highlights the need for the professionals to familiarize themselves about uncommon complications of untreated hypothyroidism.

Van Wyk-Grumbach syndrome: The importance of thyroid function tests in a child presenting with multicystic ovaries

“…It results from the loss of thyroxine inhibitory feedback and subsequent overproduction of thyrotropin-releasing hormone (TRH). Pituitary hyperplasia has been reported in patients with long-term undiagnosed and untreated primary hypothyroidism, and it is known to regress with treatment [ 6 ].…”

“…Several mechanisms have been proposed for ovarian cyst formation in this condition. Although it was previously hypothesized that thyrotropin-releasing hormone (TRH) induces the overproduction of gonadotropins and prolactin [ 5 , 6 ], the focus has shifted to the structural similarities between FSH and other hormones like TSH, and HCG, and their receptor interactions. Therefore, it is highly probable that the extremely elevated levels of TSH, typically associated with long-standing hypothyroidism, might activate wild-type FSH receptors non-selectively, resulting in ovarian hyperstimulation [ 5 , 7 , 8 ].…”

Thyroxine replacement promptly corrects vaginal bleeding in precocious menarche due to Van Wyk Grumbach syndrome

“…9 Pituitary adenoma may develop in some cases due to long standing thyrotroph hyperplasia in response to the decreased thyroid hormone. 10,11 Hyperprolactinemia develops either due to thyrotrophic hyperplasia in the pituitary compressing the pituitary stalk, thereby disrupting hypothalamic inhibition of prolactin or due to direct stimulation of prolactin release by TRH. Patients may be asymptomatic or can present with headache, visual disturbances and galactorrhoea.…”