Appendiceal endometriosis invading the sigmoid colon: a rare entity.

Purpose: We report an unusual case of endometriosis of the appendix with simultaneous invasion of the sigmoid colon.
Methods: Clinical, radiological, surgical, and histological data of the patient were reviewed, as well as the current literature on gastrointestinal endometriosis.
Results: A 41-year-old woman presented to the emergency department of our hospital with acute right lower quadrant pain, pronounced tenderness elevated white blood cell count, and increased C-reactive protein. Abdominal CT scan suggested a mucocele of the appendix. The patient was first treated with antibiotics, followed by en bloc resection of the appendix and of the sigmoid colon 2 months later. Histological examination revealed an endometriotic nodule of the appendix filling the appendiceal lumen and resulting in a mucocele which invaded the sigmoid colon wall.
Conclusions: The diagnosis of gastrointestinal endometriosis can be challenging due to the variety of symptoms it can produce. Although extremely rare, a concomitant double gastrointestinal location of endometriosis may be possible and should be considered in women of reproductive age.