Endometriosis of the duplex appendix: A case report and review of the literature

Abstract

Background: Duplication of the appendix is an infrequent congenital malformation with a complex classification. The horseshoe appendix is a subtype of the duplex appendix and is rarely reported in the literature. Endometriosis is a common gynecological disease that rarely occurs in the appendix. Moreover, horseshoe appendix combined with endometriosis has not been previously reported.

Case summary: Here, we describe a 44-year-old woman who was admitted with a 1-d history of migratory lower right quadrant pain. Physical examination was consistent with the signs of acute appendicitis. The patient underwent an emergency exploratory laparotomy. The distal tip of the appendix was in contact with the cecum by another base, or "horseshoe appendix". In addition, a small intestinal mass and an ovarian mass were identified. Subsequently, appendectomy, partial resection of the small intestine, and right oophorectomy were successively performed. The histopathology confirmed the diagnosis of acute inflammation of the duplex appendix with endometriosis, small intestine endometriosis, and ovarian endometriosis.

Conclusion: Surgeons need to be aware of the possibility of the duplex appendix when performing an appendectomy, and this study emphasizes the importance of exploring the entire abdomen.

Keywords: Appendectomy; Case report; Duplex appendix; Endometriosis; Horseshoe appendix.

Figure 1

Computed tomography scan of the patient’s abdomen. A and B: Transverse sections showing swelling of the appendix with surrounding exudation, and there is a fecalith at the root of the appendix, respectively; C: Coronal section showing swelling of the appendix with exudation and two separate fecaliths at its root; D: Transverse section showing a low density mass located in the right ovary.

Figure 2

Intraoperative photograph of the patient. The intraoperative photograph shows that there are two bases of the appendix at the end of the cecum, and both of these bases are in contact with the cecum (black arrow).

Figure 3

Histopathological appearances of the endometriosis in appendix, small intestine, and ovary. A: Hematoxylin and eosin (HE) staining shows that ectopic endometrial-type glands and stroma (thick arrows) were detected in the muscular layers (thin arrows) of the appendix (×40); B: Ectopic endometrial-type glands and stroma (thick arrows) were observed in the subserosa of the small intestine. The muscular layers are indicated by thin arrows (HE, ×40); C: Higher magnification of endometriosis (thick arrows) in the ovary (HE, ×100).