[Primary leiomyosarcoma of the small intestine in a child].

Background: Leiomyosarcomas of the digestive tract are very rare in children. They must be differentiated from benign tumors (leiomyoma, schwannoma...) and from other malignant tumors, sometimes with the aid of immuno-histochemical study.

Case Report: A five-year old girl suffered from an abdominal mass associated with fever and alteration of the general condition. An ileal tumor, 8 cm in diameter, was resected. Histological and immunohistochemical studies (anti-vimentin antibodies, anti-actin antibodies and PS100) confirmed the diagnosis of leiomyosarcoma. Uncomplete adjuvant chemotherapy failed to prevent relapse of the tumor.

Conclusion: This case confirms the bad prognosis of such a tumor.