Infantile intestinal leiomyosarcoma is prognostically favorable despite histologic aggressiveness: case report and literature review.

Intestinal leiomyosarcomas in children are extremely rare. The authors present a case of infantile intestinal leiomyosarcoma of the colon that was resected and was classified histologically as grade 2 because of abundant mitoses. The tumor cells infiltrated the submucosa and the serosal surface. Immunohistochemically, these cells were positive for alpha-smooth muscle actin but not for CD34 or CD117, by which the tumor was differentiated from gastrointestinal stromal tumor (GIST). The patient underwent follow-up without adjuvant therapy and is now doing well with no evidence of the disease for 42 months. Based on the current case and a review of 18 reported cases, it is concluded that infantile intestinal leiomyosarcoma, which is differentiated from GIST, has a favorable prognosis even when the histologic appearance is suggestive of aggressive biological characteristics. Adjuvant therapy is unnecessary when tumors are completely resected.