Inverted Appendix in a Patient With Weakness and Occult Bleeding

Abstract

Background: Appendiceal mucinous neoplasms (AMNs) are rare adenomatous primary tumors of the appendix. Although of low malignant potential, these neoplasms can cause serious potentially fatal complications such as bowel obstruction and pseudomyxoma peritonei, making prompt identification and removal of utmost importance. AMNs often present with nonspecific gastrointestinal symptoms or are asymptomatic and found incidentally.

Case presentation: A patient aged 72 years presented with generalized weakness and appeared on imaging to have acute appendicitis complicated by rupture. On colonoscopy, the patient was found to have an inverted appendix that after appendectomy was revealed to harbor a perforated low-grade AMN.

Conclusions: Although AMNs are rare, physicians should still consider it when imaging suggests appendicitis. Having AMNs as part of the differential diagnosis is especially necessary in cases, such as this one, in which the patient has appendiceal inversion, is aged > 50 years, and has concurrent colorectal neoplasms.

FIGURE 1

Colonoscopy Findings A and B, Inverted appendix can be seen; C, A sessile polyp (white arrow) and large angiodysplastic lesion (blue arrow) were found in the ascending colon.

FIGURE 2

Appendix Intraoperative View Appendiceal mucinous neoplasm is shown.

FIGURE 3

Histologic Samples of the Appendix A, Hematoxylin and Eosin stain of the serosal surface of the patient’s appendix; B, Positive pancytokeratin stain confirming the presence of atypical mucinous epithelial tumor cells on the serosal surface of the appendix; C, Hematoxylin and Eosin stain of the main tumor; nuclear atypia, significant amounts of mucin, and attenuation of the normal appendiceal epithelium by mucin can be seen.