Urogenital Imaging

Anorchia

congenital absence of the testis. It is one of the causes of nonpalpable testis. Unilateral anorchia (monorchism) is more common on the left side, and may be caused by intrauterine testicular torsion or other forms of compromised vascular supply to the testis during descent. The testis in patients with monorchism is not an increased risk of malignancy. Bilateral anorchia, complete bilateral absence of the male gonads, is relatively rare and results in primary testicular failure. These patients are genotypically and phenotypically male, and present clinically with a small, empty and unpigmented scrotum, a micropenis, and delayed onset of puberty. Hormonal studies confirm the diagnosis, documenting low serum testosterone level and elevated luteinizing hormone (LH) and follicular-stimulating hormone (FSH) levels. Patients with bilateral anorchia do not show a rise in serum testosterone in response to human chorionic gonadotrophin (HCG) administration. Determination of LH and FSH responses to exogenous gonadotropin releasing hormone may also be useful. While ultrasound, CT and MRI of the abdomen, pelvis and scrotum may document absence of testicular tissue, laparoscopy is the definitive diagnostic test. Replacement therapy with testosterone is recommended.

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