Leiomyosarcoma of the rectosigmoid junction, a case report.

Leiomyosarcomas are a rare type of neoplasm of the digestive tract with an estimated presentation of 0.1% predominantly between the fifth and sixth decade of life [1]. We report the case of a 61 years old male patient without previous medical conditions, with melena and constitutional symptoms and an extensive rectal mass with a final diagnosis of diagnosis leiomyosarcoma of the large intestine, grade II (FNCLCC). Given the rarity of this pathology and the fact that it does not present specific clinical, endoscopic, and imaging features made it difficult to differentiate from other entities of greater frequency such as rectal adenocarcinoma and GIST, representing a real diagnostic challenge.