Primary leiomyosarcoma in the colon: A case report.

RATIONALE

Leiomyosarcoma (LMS) is a common type of soft tissue sarcoma. Primary colonic LMS in general is a very rare entity, accounting for 1% to 2% of gastrointestinal malignancies.

PATIENT CONCERNS

We report a case of 55-year-old female who presented with a sudden onset of sharp right lower quadrant abdominal pain. Electronic colonoscopy showed a normal lumen. However, an abdominal computed tomography scan revealed a mass of soft tissue attenuation inseparable from the ascending colon which appeared as a gastrointestinal stromal tumor (GIST).

DIAGNOSES

It is important to diagnose LMS definitively by immunohistochemical profiling of smooth muscle actin, desmin, and CD34.

INTERVENTIONS

She underwent laparotomy and right hemicolectomy, and histology confirmed a colonic LMS. The patient received no oncological treatment after surgery.

OUTCOMES

No recurrence or metastasis was observed at 5 months postoperatively. It is crucial to identify colonic LMS precisely based on immunohistochemistry, and thereby distinguish it from GIST.

LESSONS

Further investigation on LMS cases so far is required to establish standard treatment strategies.