Peritoneal lesions caused by Enterobius vermicularis suspected to be metastases of ovarian malignancy

Enterobius vermicularis, also known as pinworm, is a helminth that commonly causes intestinal parasitic infestation. E. vermicularis can also cause extraintestinal infestations. We report a case of lower abdominal pain and intermittent vaginal bleeding in a 45-year-old woman who was referred to our gynaecology department. On investigation, a transvaginal ultrasound showed a multilocular cyst in the left ovary, along with elevated levels of cancer antigen 125. Consequently, a laparoscopic salpingo-oophorectomy was performed. A biopsy of atypical peritoneal lesions revealed remains of E. vermicularis. Peritoneal lesions are a rare complication of enterobiasis, and the diagnosis of this complication is usually delayed by limitations in diagnostic options. Although extraintestinal enterobiasis does not require treatment because it is the last stage of the parasitic cycle, primary intestinal infestation requires treatment with mebendazole.