Endometriosis-associated Tumor of the Sigmoid Colon—A Case Report—

Key Points

• This report aims to describe a rare case of endometriosis-associated tumor located in the sigmoid colon.
• Case report of a 75-year-old female with a history of endometriosis.
• Lower gastrointestinal endoscopy identified a type 3 lesion in the sigmoid colon.
• Preoperative imaging and biopsy confirmed adenocarcinoma diagnosis.
• Laparoscopic sigmoid colectomy was performed, followed by pathological analysis.
• Pathological findings indicated the tumor originated in the muscularis layer of the sigmoid colon.
• Immunohistochemistry revealed the tumor was estrogen receptor positive.
• Lesions consistent with endometrial glands and stroma were identified near the tumor, supporting a diagnosis of endometriosis-associated intestinal tumor (EAIT).
• No distant metastasis was noted, with a preoperative diagnosis of cT3N1bM0, cStage IIIb.