[A Case of Osteomyelitis with a Granulomatous Lesion Caused by Salmonella Infantis].

We report herein on a case of osteomyelitis with a granulomatous lesion caused by Salmonella enterica subsp. enterica serovar Infantis (Salmonella Infantis). A 30-year-old Japanese man presenting with a 3-week history of left ankle pain was suspected to have either a tumor or osteomyelitis, on the basis of imaging study findings. He underwent a surgical resection of the lesion. Histopathological examination revealed a granuloma. However, S. Infantis was cultured from the biopsy sample. Cefazolin was initially administered as empirical therapy. We switched the antibiotic to ampicillin on the basis of the anitibiotic-susceptibility test results. Six weeks after intravenous ampicillin therapy, we switched to oral ciprofloxacin. He has had no recurrence in the 3 years after treatment completion. Salmonella osteomyelitis is rare and this pathogen seldom causes a granulomatous lesion. According to the findings in our case, Salmonella spp. should be considered as one of the differential diagnoses for granulomatous lesions in the bone.