No abstract

Introduction: Endometriosis-associated intestinal tumours represent the malignant trasformation of gastrointestinal endometriosis. Clinical features are similar to a colon tumor with abdominal or pelvic pain, dyschezia or bloody stools. Intestinal occlusion or perforation have also been described as a first presentation. The diagnosis is often postoperative and it is based on specific immunohistochemical patterns (CK7+/CK20-). Case presentation: In this article we present a rare case of a woman with a malignant trasformation of an endometriotic lesion of the sigmoid colon, who underwent emergency surgery for intestinal occlusion. She underwent an exploratory laparotomy and Hartmann resection. The immunophenotypic analysis of the specimens revealed the following pattern: CK20-, CK7+, compatible with the diagnosis of endometrioid adenocarcinoma. Conclusions: Endometrioid carcinoma is a rare tumor, difficult to diagnose preoperatively because clinically it presents with symptoms similar to those of patients with sigmoid adenocarcinoma. A high index of suspicion in conjunction with careful histological and immunohistochemical examination (CK7, CK20, CDX2, CD10, ER, and PR) is important for establishing a correct diagnosis.