Mucocele of the appendix due to endometriosis: A rare case report

Figure 1 Preoperative image of the mucocele. A: Computed tomography (CT) (axial image); a tumor was detected (arrows); B: CT (coronal image); a tumor was detected (arrows); C: Colonoscopy; submucosal tumor-like elevations of the appendiceal orifice; D: Magnetic resonance imaging (MRI) (T1-WI, axial image); E: MRI (T2-WI, coronal image).

Figure 2 Macroscopic appearance of the resected specimen. A: Resected specimen contained thin-walled cystic masses; B: Cystic masses contained yellow mucin. Endometriosis was observed around the cyst (circle).

Figure 3 Pathological findings and immunohistochemical staining. A: Appendiceal mucosa was observed on the cyst wall; B: Estrogen receptor; C, D: Obstructive lesion of the appendiceal lumen. Endometriosis and smooth muscle hypertrophy were observed in the muscle layer (hematoxylin/eosin staining, C: × 20; D: × 100).