Teaching Case

This is an interesting case both clinically and radiographically of a 37-year-old female presenting with right iliac fossa pain. It represents a common diagnostic pathway with an unusual outcome!

This 37-year-old lady presented to the general surgical take with a 1 day history of right iliac fossa pain, which was sharp and colicky in nature. She felt generally unwell, but with no other specific symptoms except that she reported a prolonged menstrual bleed, lasting 2 weeks. She had previously been in good health with no other past medical history. Examination of the abdomen revealed tenderness in the right iliac fossa and suprapubic areas. Urinalysis undertaken was positive to blood with Beta HCG pregnancy test negative. Abdominal radiograph (Figure 1) was obtained and this demonstrates an intrauterine device and an unusual calcification projecting over the sacrum. With an unclear diagnosis, computed tomography was undertaken (Figures 2 & 3) demonstrating a right ovarian cyst, confluent with an 8cm mass in the midline. This has a central, densely calcified component, and is typical of an ovarian dermoid. Laparotomy was undertaken and a torted ovary containing this cystic mass was resected. Histological analysis confirmed that this was a mature cystic teratoma (dermoid cyst) with no evidence of malignancy.

This is an interesting cause of right iliac fossa pain with a subtle finding on plain radiography, which should raise the suspicion of an otherwise covert pathology. The CT images show the uterus with the IUD in situ in the centre of the pelvis. Anterior to it is a complex mass, which in the right iliac fossa takes the form of a large cyst and more centrally there is a highly complex 8cm component. This contains multiple tissue densities representing fat, soft tissue, fluid and the densely calcified central component. This is a typical appearance of a mature cystic teratoma or otherwise known as a dermoid cyst.