title: Unusual presentation of an infected primary hydatid cyst of biceps femoris muscle.
abstract: Hydatid cysts of the musculoskeletal system are rare. Unusual magnetic resonance imaging (MRI) findings of an infected primary hydatid cyst of the biceps femoris muscle are presented in a 40-year-old man on hemodialysis for chronic renal failure. No daughter cysts were present within the mother cyst cavity, but there was a fatty nodule which has not previously been described in a muscular hydatid cyst. Although the cyst was infected secondarily, no surrounding soft tissue inflammatory reaction was noted. Hydatid cysts should be included in the differential diagnosis of unusual soft-tissue masses in regions where the disease is endemic.
mesh_terms: D000328:Adult; D004443:Echinococcosis / Q000150:complications*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal; D009135:Muscular Diseases / Q000209:etiology*; D006435:Renal Dialysis; D018461:Soft Tissue Infections / Q000209:etiology*