Torsion of a rudimentary uterine horn at 22 weeks of gestation.

Rudimentary uterine horn is an uncommon abnormality of the female reproductive tract. Torsion of rudimentary uterine horn in pregnancy is even rarer. A case of successful excision of distorted rudimentary uterine horn in the second trimester, which caused severe abdominal pain, is described. A congenital absence of the right kidney was discovered simultaneously. The pregnancy continued uneventfully until term delivery.