{"paper_id":"15ce1664-7d32-455f-a18e-9846a2fba1f4","body_text":"Appendicular endometriosis mimicking \nappendicitis \nF . Claus 1, D. Vanbeckevoort 1, G. De Hertogh 2, V. Vandecaveye 1,\nPh. Koninckx 3\nA 31-year-old woman presented to the emergency department \nwith right lower quadrant pain. The pain had started three days \nearlier  with increasing intensity postprandially, when walking and \nin right decubitus position. Completion of her last menstruation \nwas one week before admission. Clinical examination confirmed \nthe right fossa pain with a negative psoas sign. Laboratory findings \nrevealed normal white blood cell count (6.4 x 109/L) and a mild \nelevation  of the CRP (12.6 mg/L). Abdominal ultrasound and CT \nshowed a pathological wall thickening of the appendix extending \nto the caecum and with infiltration of the peri-appendicular fat and \na thickening of the adjacent peritoneal membrane (Fig. A, B). There \nwas no free fluid. Based on the clinical and imaging findings, the \ntentative diagnosis of appendicitis was made, and a laparascopic \nappendectomy and a partial caecal resection was performed. \nMicroscopic examination of the appendix showed only minor signs \nof inflammation, but the presence of fibrous tissue intermixed with \nendometrial glandular tissue. The latter was confirmed by CK-7 and \nCD-10 positive staining. Delayed second-look laparascopy showed \nadhesion of both ovaries towards the uterus and endometriosis \nsites in the rectovesical excavation and the recto-uterine pouch. \nRetrospective analysis of the CT -images depicts the close proximi -\nty of both ovaries to the uterine body (Fig. C). \nComment \nEndometriosis is a condition in which endometrial tissue is \nfound outside the uterine cavity. It is typically seen during the \nreproductive years and the estimated prevalence ranges between \n5-10%. Endometriosis is a common finding in women with infer -\ntility and the main symptom is (pelvic) pain. Common sites of \nendometriosis are the ovaries, the recto-uterine pouch, the recto -\nvesical excavation, the posterior broad and uterosacral ligaments, \nthe fallopian tubes and the sigmoid. Appendicular endometriosis is \nrare with an estimated prevalence 0.05% in the general population \nand up to 5% in series with female patients presenting with chron -\nic pelvic pain. In the absence of clinical suspicion, the pre-operative \ndiagnosis of appendicular endometriosis is very difficult. Both \nsymptoms and imaging findings are very similar to appendicitis, as \nillustrated in the case above. Therefore, in reproductive-age women \npresenting with right lower quadrant pain, no (or only minor) \n elevated inflammatory blood parameters and pathologic imaging \nfindings of the appendix, endometriosis should be considered in \nthe differential diagnosis. CT has a rather low accuracy in detecting \nendometriosis, but careful inspection of the pelvis for other \nimplants (e.g. adnexal endometrioma) or adhesions can favour the \ndiagnosis, which can then be confirmed by transvaginal ultra -\nsound, MR imaging or laparascopy. \nJBR–BTR, 2010, 93: 105. \nIMAGES IN CLINICAL RADIOLOGY \n1. Department of 1. Radiology, 2. Pathology and 3. Gynecology and \nObstetrics, University Hospitals Leuven, Leuven, Belgium. \nA\nB\nC","source_license":"CC0","license_restricted":false}