ESPE Abstracts

Background: Hydrometrocolpos is a condition resulting in distension of the vagina and uterus due to accumulation of secretions (other than blood), caused by increased oestrogenic stimulation and vaginal outflow obstruction. The incidence in term neonates is 0.00014-0.001%. The condition presents at extremes of childhood, at birth when maternal circulating hormones are raised and at menarche when oestrogen production commences. Pseudohypoaldosteronism (PHA) due to obstructive uropathy, urinary tract infections and congenital urogenital malformations have been reported in the literature, however, there are no reports of PHA associated with hydrometrocolpos due to a common urogenital tract.

Case Report: A female baby, preterm at 35weeks gestation, birthweight of 2100g was noted to have an abdominal mass soon after birth. Ultrasound scan showed a round, central abdomino-pelvic cystic mass with bilateral renal major pelvic-calyceal dilatation and hydronephrosis. An MRI demonstrated huge distension of the vagina and uterus with compression of adjoining structures consistent with hydrometrocolpos. Cysto-vaginoscopy revealed a common urogenital tract. The hydrometrocolpos was drained and child later discharged home.

She subsequently re-presented at 6 weeks of age, unwell, vomiting, pale, tachycardic with poor weight gain. Her results showed a metabolic acidosis, anaemia (haemoglobin 69g/dL), hyponatraemia (sodium 117mmol/L), hyperkalaemia (potassium 7.1mmol/L) and abnormal renal function. Urine examination showed microscopic haematuria but no suggestion of infection. She was initially treated for salt losing adrenal crisis so received a 10ml/kg bolus of 0.9% sodium chloride, hydrocortisone and fludrocortisone. She also received bicarbonate, with intravenous calcium gluconate and salbutamol for treatment of hyperkalaemia, and a blood transfusion as imaging showed a re-accumulation of the mass with internal haemorrhage. After stabilisation she had cystovaginostomy and only milky fluid was drained from the mass. Further investigations demonstrated raised aldosterone and renin and cortisol, 17-hydroxyprogesterone and urinary electrolytes within the normal ranges. These results and resolution of signs following surgery demonstrate a pseudohypoaldosteronism.

Conclusion: Whilst cases of PHA due to obstructive uropathy has been described previously, our case is unique as to our knowledge, there are no reports of obstruction uropathy secondary to hydrometrocolpos secondary to a common urogenital tract. The mechanism by which PHA occurs in obstruction involves renal tubular dysfunction due to pressure from hydronephrosis and the release of intrarenal cytokines. In addition, there is an immature or resistant renal tubular responsiveness to aldosterone during infancy. This leads to a picture with high circulating aldosterone levels but hyponatraemia and hyperkalaemia. Clinicians should be aware of this uncommon presentation.