[Acute rectal bleeding from malignant stromal tumor]

Stromal tumors of the rectum are rare. The most common symptoms are rectal bleeding, pain, constipation and obstruction. A case report of a 61 years old female admitted with acute bleeding due to malignant stromal tumor of the rectum is described. Upon admission the clinical and laboratory findings necessitance blood transfusion. Preoperative assessments revealed a large tumor located in the rectal wall with extension to the adjacent tissues. The histologic features of needle biopsy was compatible with gastrointestinal stromal tumor. Abdominoperineal excision of the rectum was performed. The definitive histological examination showed a gastrointestinal stromal tumor (GISTs), spindle cell type with mucosal invasion, vast necrosis and highly mitotic activity. The tumor cells coexpressed CD34 and smooth muscle actin and were negative for staining desmin and S-100 protein. Adjuvant chemotherapy was given. The patient died 7 months after the operation due to widespread metastases. We decided to describe a rare malignant stromal tumor of the rectum with uncommon clinical presentation.