We report a 5.5-year-old boy who underwent autologous peripheral blood stem
cell transplantation for high-risk acute lymphoblastic leukemia and who ha
d two abdominal masses develop 6 months later. Macroscopically complete res
ection of the abdominal tumors was performed and revealed a well-differenti
ated leiomyosarcoma. Smooth muscle tumors, benign or malignant, are increas
ingly recognized in children with various immunodeficiencies: the associati
on with acute lymphoblastic leukemia is rarely described.