Romina Deldar, MD1, Chaitanya Vadlamudi, MD1, Gao L Chen, MD2. 1Georgetown University Hospital, 2Kaiser Permanente, Mid-Atlantic States
INTRODUCTION: Acute appendicitis can arise from many etiologies. We present a case of acute appendicitis that was radiographically suspicious for appendiceal mucocele. However, final pathology revealed luminal obstruction secondary to cecal endometriosis. Cecal endometriosis is exceedingly rare, and only a few case reports describe this as a cause of appendicitis.
METHODS AND PROCEDURE: A healthy 33-year-old woman with no prior gynecologic history presented on day five of her menstrual cycle with 48-hours of right lower quadrant abdominal pain, nausea, emesis, and leukocytosis of 13,900/mm3. Computed tomography (CT) of the abdomen revealed a 10-centimeter, distended and fluid-filled appendix, suspicious for mucocele (Figure 1). As clinical and radiographic evidence was consistent with acute appendicitis, the patient was taken for laparoscopic appendectomy. Intraoperatively, the appendix was noted to be massively dilated and associated with a firm cecal mass just beyond the appendiceal base. These findings raised suspicion for appendiceal mucinous neoplasm, therefore the operation was converted to open. A partial cecectomy was performed in addition to appendectomy. The appendix, cecal base, and mesoappendix were removed en bloc with no spillage. No mucinous deposits or other abnormalities were identified. The patient tolerated the procedure well and was discharged home on post-operative day one.
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Figure 1. CT axial view showing dilated fluid-filled appendix.
RESULTS: Three independent pathologists reviewed the specimens and found no evidence of an appendiceal mucinous neoplasm. Fluid within the appendiceal lumen did not stain positive for mucin. The specimen was consistent with acute appendicitis without evidence of malignancy. Interestingly, the cecum at the appendiceal base was noted to contain endometrial glands with surrounding stromal tissue in the muscularis propria, consistent with endometriosis (Figure 2). During menses, increased inflammation and tissue edema of the endometrial tissue positioned at the appendiceal base may have led to luminal obstruction and subsequent acute appendicitis. The patient had no other symptoms of endometriosis.
Figure 2. Focus of endometriosis in the muscularis propria (MP) of the cecum. Endometrial gland (E) and surrounding stromal tissue (S). Hematoxylin and eosin stain, 100x.
CONCLUSION: Cystic dilatation of the appendix can result from luminal obstruction secondary to a wide spectrum of benign or neoplastic causes. Clinically suspicious appendiceal mucocele should be resected intact to prevent mucinous deposits from seeding the abdomen and causing pseudomyxoma peritonei. Pathologic examination can reveal an unexpected diagnosis. This case simultaneously highlights an unusual presentation of endometriosis and an extraordinarily rare etiology of acute appendicitis.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 92294
Program Number: P019
Presentation Session: Poster Session (Non CME)
Presentation Type: Poster
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