Findings: Ultrasound demonstrated marked enlargement and wavy morphology of the adrenal glands. The uterus was normal in appearance, but the vagina was fluid-filled.

Diagnosis: Congenital adrenal hyperplasia.

Discussion: Congenital adrenal hyperplasia is a defect in steroid synthesis which is transmitted through an autosomal recessive trait. The deficiency involves the 21-hydroxylase enzyme in 90% of cases. There are two forms of the disease: a severe salt-wasting form and a virilizing form. The diagnosis is based on physical exam and hormonal analysis.

Ultrasound is also useful in the diagnosis to evaluate the size and morphology of the adrenals as well as to evaluate the internal sexual organs. Sivit et al found that mean adrenal length greater than 20 mm and mean width greater than 4 mm suggest the diagnosis, however, the adrenals in CAH may be normal in size. Avni, in his case series of three patients, suggested that a wavy for cerebriform appearance to the glands was specific for the diagnosis. Congenital adrenal hyperplasia in males manifests itself with an enlarged penis at birth and isosexual precocious puberty. CAH in females presents with enlargement of the clitoris at birth, partial or complete fusion of the labia, and occasionally a urogenital sinus. Most likely labial fusion in this infant was the cause of her hydrocolpos. Females with CAH have a normal uterus, ovaries, and upper vagina. Rarely there is late onset of symptoms.

References:
Avni EF, Rypens F, Smet MH, et al. Sonographic demonstration of
congenital adrenal hyperplasia in the neonate: the cerebriform pattern.
Pediatric Radiology. 1993; 23:88-90.

Sivit CJ, Wellington H, Taylor GA, et al. Sonography in Neonatal Adrenal
Hyperplasia. AJR. 1991;156:141-143.

Gooding GA. Adrenal, Pancreatic, and Scrotal Ultrasound in Endocrine
Disease. Radiologic Clinics of North America. 1993;31(5):1069-1083.

Isselbacher et al. Harrison’s Principles of Internal Medicine 13th ed. 1994:1968-1970.

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