Laboratory Studies
A logical workup in infants with ambiguous genitalia includes the following:
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Chromosomal analysis
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Endocrine screening
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Serum chemistries/electrolyte tests
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Androgen-receptor levels
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5-Alpha-reductase type II levels
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Antimüllerian hormone (AMH)/müllerian-inhibiting substance (MIS) level
Imaging Studies
Renal/bladder ultrasonography (US) can be performed at the bedside in the neonatal intensive care unit (NICU). US usually allows visualization of a neonate's adrenal glands, which may be enlarged in congenital adrenal hyperplasia (CAH); however, normal adrenal glands on US do not exclude CAH. When adrenal glands are enlarged in patients with CAH, they have a cribriform appearance. US also helps identify müllerian structures. In a neonate, ambiguous genitalia, enlarged adrenal glands, and evidence of a uterus are virtually pathognomonic for CAH.
Genitography helps determine ductal anatomy. In a neonate with ambiguous genitalia, a catheter can be inserted into the distal urogenital sinus (urethra). Contrast is injected to outline the internal ductal anatomy. Findings may indicate normal urethral anatomy, an enlarged utricle, a müllerian remnant in a male, a common urogenital sinus, or an area of vaginal and urethral confluence in female neonates.
Computed tomography (CT) and magnetic resonance imaging (MRI) are usually not indicated but may help identify internal anatomy.
Other Tests
Cystourethroscopy before or during the definitive reconstructive surgery may help to better define the anatomy of the urogenital sinus and the exact location of the confluence (where the vagina meets the urethra), whether high, intermediate, or low.
Procedures
Open exploration, though rarely used nowadays, may help identify internal duct anatomy and allow gonadal tissue to be obtained for histologic characterization; however, many authors advocate laparoscopy for this purpose.
Laparoscopy under general anesthesia allows rapid identification and delineation of the internal duct anatomy without the morbidity associated with open exploration. Biopsy of gonads may be performed laparoscopically by placing additional trocars.
Histologic Findings
Histologic analysis of gonadal biopsy specimens may identify ovarian tissue, testicular tissue, ovotestes, or streak gonads.
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Patient with 46,XX disorder of sex development (DSD). Note masculinized appearance of genitalia, with enlarged phallus and scrotal appearance of labia.
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Patient with congenital adrenal hyperplasia (CAH; 46,XX DSD). Note phalluslike clitoris and empty scrotal appearance of labia majora.
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Same patient with congenital adrenal hyperplasia (CAH; 46,XX DSD), after feminizing genitoplasty surgery. Note achievement of three components of surgery: clitoroplasty, vaginoplasty. and labiaplasty. Upper catheter is in urethra and lower one in vagina.
Tables
Previous Term |
Revised Term |
Female pseudohermaphrodite |
46,XX DSD |
Male pseudohermaphrodite |
46,XY DSD |
True hermaphrodite |
Ovotesticular DSD |
XX male |
46,XX testicular DSD |
XY sex reversal |
46,XY complete gonadal dysgenesis |
