Mayer-Rokitansky-Küster-Hauser Syndrome - Remembering a Common Cause of Primary Amenorrhea

Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome refers to congenital absence of the vagina with variable uterine development. It constitutes the second most common cause of primary amenorrhea.

Case report: A 16yo female patient is referred to Pediatric Endocrinology consultation for primary amenorrhea. She noticed thelarche and pubarche at the age of 12-13yo. Systemic illness and chronic medication use was denied. There was no family history of amenorrhea or genetic diseases. Mother and sister attained menarche at 14-15yo. On physical examination: weight of 53.4 kg; height of 157.8 cm, SDS -0.71 (midparental-height 160.5 cm, SDS -0.33). No dysmorphic characteristics, normal appearing female external genitalia and breasts, with normal axillary and pubic hair development (Tanner stage B4P4). Performed at the outpatient clinic, she had a normal biochemical investigation (follicle stimulating hormone 5.9 UI/L; luteinizing hormone 10.3 UI/L; Estradiol 157.4 pg/mL; prolactin 25.0 ng/mL; thyroid stimulating hormone 1.698 uUI/mL) and a pelvic ultrasound (images not available) describing a uterus of prepubertal dimensions; both ovaries with normal configuration and some infra-centimetric follicles. Therapeutic trial with oral contraceptive was prescribed, with no withdrawal bleeding. Gynecological evaluation revealed an imperforate hymen, without hematocolpos or hematic drainage with hymenotomy, and raised the suspicion of malformation (rectoabdominal examination without palpable cervix and uterus). Abdominal and pelvic MRI confirmed the complete absence of uterus, cervix and vagina, with normal ovaries, diagnosing MRKH syndrome. No renal anomalies were observed; an L5-S1 discal hernia was described.

Conclusion: This clinical case emphasizes the importance of considering MRKH syndrome in the differential diagnosis of primary amenorrhea, especially if normal secondary sexual characters and hormonal evaluation. The pelvic ultrasound describing a small uterus should have been an alert to this diagnosis. This condition is associated with renal defects and skeletal deformities in one-fourth of the patients. The approach needs to be multidisciplinary, without neglecting psychological support.