Rectal Leiomyosarcoma: An Unusual Rectal Malignancy Mimicking Fecal Impaction in a 19-Year-Old Man

A 19-year-old man with a 2-month history of lower abdominal pain and a 10-kg weight loss during the past year presented with difficulty in passing stool and blood in his stool for 2 days. Digital rectal examination revealed a large solid mass in the rectum. Except for iron deficiency anemia (hemoglobin, 9.3 g/dL; normal, 13–17 g/dL), laboratory test results were unremarkable.