Adnexal torsion involving hydatids of Morgagni: A rare cause of acute abdominal pain in adolescents

OBJECTIVE: Hydatids of Morgagni are common embryonal remnants of the müllerian duct and among the infrequent causes of adnexal torsion. The purpose of this study was to investigate the occurrence of adnexal torsion involving hydatids of Morgagni, as well as its possible mechanisms. METHODS: A database search was conducted for cases of adnexal torsion treated in our institution from January 2002 to July 2005. These cases were analyzed, focusing on a subgroup of adolescents with adnexal torsion involving the hydatids of Morgagni. RESULTS: There were 76 patients with adnexal torsion. The rate of hydatid of Morgagni torsion was 26% (4 of 15 cases, 95% confidence interval [CI] 0.15-0.51) in the adolescent subgroup (10-19 years old), compared with 0% (0 of 61 cases, 95% CI 0-0.048) in the adult subgroup. The difference between the hydatid torsion rates in the two subgroups was statistically significant (P = .01, 95% CI 0.001-0.532). The four patients with hydatid torsion (postmenarchal girls, aged 13-18 years) were managed with laparoscopic adnexal detorsion and cystectomy of the affected hydatid of Morgagni. At surgery, we noted three different mechanisms of hydatid torsion: torsion of the adnexa together with torsion of the hydatid of Morgagni, torsion of the hydatid of Morgagni with intact adnexa (n = 2), and entanglement of the hydatid's pedicle around the distal fallopian tube. The hydatids of Morgagni were observed on the preoperative transabdominal ultrasonogram in only one patient and appeared as a simple cyst. CONCLUSION: Adnexal torsion involving the hydatids of Morgagni appears to be more common in adolescents than previously thought.