Abdominal-wall myositis secondary to intra-arterial chemotherapy for femoral osteosarcoma

With the increasing application of intra-arterial chemotherapy (IAC), new s ide-effects are encountered. We describe two children with proximal femoral osteosarcoma who developed focal myositis of the abdominal wall musculatur e after IAC, In both cases, myositis presented as abdominal pain and mimick ed acute abdomen, US demonstrated asymmetrical thickening of abdominal-wall musculature in the right lower abdomen. This diagnosis should be considere d when evaluating the patient with unexplained abdominal pain and a history of IAC.