Pelvic abscess masquerading as urachal malignancy—a rare presentation of retained appendicolith

Dropped or retained appendicoliths are uncommon complication of laparoscopic appendicectomies, and rarely they have been reported to cause complications such as pelvic abscesses or enterocutaneous fistulas. We reported on a rare presentation of a pelvic abscess masquerading as urachal malignancy in a 41-year-old male, 2 years after his laparoscopic appendicectomy. As urachal malignancy could not be unequivocally excluded on imaging findings alone, en bloc resection of this mass and partial cystectomy were performed. Histopathology study revealed pelvic abscess with no evidence of malignancy and a central calcification which corresponded to a faecolith identified on pre-appendicectomy imaging. We contributed this rare presentation to the limited existing literature about complications of retained appendicoliths. As laparoscopic appendicectomies are performed commonly as the standard of care of appendicitis, care should be taken to extract appendicoliths completely to prevent complications.