A rare confounder in a case of ovarian torsion

Abstract

We report a 26-year-old woman who presented to the Emergency Department in late 2011, with severe right iliac fossa pain, nausea and vomiting after two weeks of mild generalised abdominal pain. There was no history of fever, urinary symptoms, vaginal bleeding or discharge, or change in bowel habit. Apart from a previously diagnosed right ovarian cyst, her past medical and surgical histories were unremarkable. The cyst had been noted incidentally on a routine ultrasound in 2006 and measured 6.49 cm in diameter. It was simple in nature, unilocular and anechoic. The patient had been having annual follow-up with ultrasound surveillance. Due to the cyst’s lack of increase in size and its asymptomatic nature, the patient opted against surgical intervention. Her obstetric history consisted of two successful spontaneous vaginal deliveries in 2005 and 2006. She was not on any medications, had no known allergies and was a non-smoker. On physical examination, there was localised tenderness and involuntary guarding in the right iliac fossa. Vaginal examination revealed mild right adnexal tenderness and cervical excitation tenderness. No blood or purulent fluid was noted in the cervical os. Laboratory investigations revealed a leucocytosis (13.4 109/ L; normal range 4.0–11.0 109/L), predominately neutrophils (10.28 109/L; normal range 2.0–8.0 109/L). Biochemistry was normal. b-Human chorionic gonadotropin (bHCG) was negative and urinalysis normal. Transabdominal ultrasound revealed a thin-walled simple anechoic cyst involving the inferior pole of the right ovary, measuring 6 cm in diameter, with a trace of adjacent free fluid. Colour Doppler flow was seen within the right ovary. The uterus and left ovary were normal. The appendix was not visualised. Differential diagnoses included appendicitis, ruptured right ovarian cyst, ectopic pregnancy, right ovarian torsion and pelvic inflammatory disease. Diagnostic laparoscopy was performed. A right ovarian torsion was identified, with the ovary tangled around a fibrous intraperitoneal band connecting the terminal ileum to the anterior abdominal wall at the level of the umbilicus (Fig. 1). The right ovary did not appear necrotic in appearance. The fibrous intraperitoneal band was then excised. The right ovarian cyst was then punctured, drained and stripped from the ovary, preserving the ovary. Post-operative recovery was unremarkable and the patient was discharged the following day. Histopathological examination of the band was consistent with an obliterated vitello-intestinal duct, persisting as a fibrous intraperitoneal band. The cyst was consistent with an ovarian cystadenoma. The vitello-intestinal duct conveys nutrients from the yolk sac to the foetus during the first eight weeks of gestation, after which it normally disappears. Persistence of the vitellointestinal duct results in various types of anomaly [1]. Most commonly seen is a Meckel’s diverticulum, while others include a patent vitello-intestinal duct, fibrous intraperitoneal band, umbilical sinus or vitello-intestinal duct cyst [2]. The commonest complication of the fibrous intraperitoneal band is usually an intestinal obstruction [3]. Unilateral ovarian torsions occur most commonly in relation to previous pelvic surgery, ovarian cysts or neoplasms, or an elongated utero-ovarian ligament [4,5]. An extensive literature search of Ovid MEDLINE and PubMed did not reveal any prior publications of vitello-intestinal remnants causing ovarian torsion. In conclusion, a persistent vitello-intestinal duct anomaly causing right ovarian torsion is a rare occurrence. We believe this report constitutes the only such case in the English-language literature. The possibility of this rare diagnosis should be entertained when treating patients with ovarian torsion. It is also recommended that large ovarian cysts should be followed more carefully and if persistent, managed surgically in a controlled fashion to avoid such complications as haemorrhage or torsion.