The Virilized Infant Who Wasn’t, a Case Series of Apparent Clitoromegaly in Congenital Hypothyroidism
Year: 2026
Type: conference-abstract
Abstract: Introduction: Congenital hypothyroidism (CH) is among the commonest preventable causes of intellectual disability and is typically identified through newborn screening. Clitoromegaly as a presenting feature of CH is exceedingly rare and often mistaken for a virilizing disorder warranting extensive endocrine workup. We describe two infants with CH presenting with apparent clitoromegaly that resolved completely with levothyroxine replacement. Case Report: The first infant was born at 39 weeks gestation with a birth weight of 2.8 kg, third in birth order of a non-consanguineous marriage, and presented at 2 months 20 days of age with failure to thrive and lethargy. The child also had hypoglycemia, which on workup was not suggestive of hyperinsulinemia or ketotic causes, and was therefore suspected to be due to hypothyroidism. Examination revealed isolated clitoromegaly (clitoral length 1 cm), Prader stage 1, without labioscrotal fusion or palpable gonads. Biochemistry confirmed severe primary hypothyroidism, with TSH 101 mIU/L and free T4 0.39 ng/dL. Karyotype was 46XX, and a stimulated steroid panel was normal, excluding congenital adrenal hyperplasia; thyroid scintigraphy confirmed dyshormonogenesis. The second infant was detected incidentally during neonatal evaluation, with an enlarged clitoral index (10 x 5 mm, 50 mm2), Prader stage 1, without goitre or macroglossia. Cord blood TSH exceeded 100 mIU/L with free T4 0.37 ng/dL, and thyroid scintigraphy confirmed an ectopic, hypoplastic lingual thyroid. Both infants were started on levothyroxine, with complete resolution of clitoromegaly (clitoral index 0.27 in the first infant) and normal TSH and free T4 by 10 months of follow up. Conclusion: Clitoromegaly in CH may reflect prolonged TSH elevation acting on gonadal or genital tissue through gonadotropin receptor cross-reactivity, or an associated transient gonadotropin surge. Recognizing this reversible association can prevent unnecessary virilization workup and surgical referral, and underscores the value of universal newborn thyroid screening.
Source: Thyroid Research and Practice
Institution: St.John's Medical College Hospital
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7220865960