Pyomyositis in the course of acute lymphoblastic leukemia

Pyomyositis is a term used to asses pyogenic infection of the skeletal muscle and develops as the result of bacteriemia and occurs most commonly in patients with various immunosuppressive diseases. Pyomyositis should be considered in the differential diagnosis in patients complaining of intensive muscle pain and fever. The usual causative organism is Staphylococcus aureus. We present a 3-year-old boy with acute lymphoblastic leukemia (ALL) and pyomyositis caused by Pseudomonas aeruginosa diagnosed in the course of induction therapy. The diagnosis of pyomyositis in the crural muscles of both legs was given based on imaging examinations: ultrasonography and magnetic resonance.