Leiomyosarcoma of the small bowel presenting as an acute small bowel obstruction.

Leiomyosarcoma is a subtype of soft-tissue sarcoma, which is a rare soft-tissue malignancy comprising < 1% of adult cancers. There are a variety of etiologies of small bowel obstruction. Infrequently, small bowel malignancies can first present as small bowel obstruction. In exceedingly rare cases, leiomyosarcomas can be the offending malignancy. A 53-year-old male presented to the emergency department with several weeks of persistent right abdominal pain, nausea, and vomiting. Computed tomography scan revealed a central necrotic mass within the right lower quadrant originating from the small bowel. The patient underwent exploratory laparotomy to relieve the obstruction and a mass was identified originating from the terminal ileum that adhered to surrounding structures. Pathological analysis determined the mass to be small bowel leiomyosarcoma. Leiomyosarcoma is definitively diagnosed after primary resection with histopathology and immunohistochemistry. As opposed to other small bowel neoplasms, surgical resection with negative margins is the only potentially curative option.