A case of Salmonella osteomyelitis mimicking a malignant tumor of the humerus in an immunocompetent adult patient identified using broad-range polymerase chain reaction with sequencing of a biopsied specimen.

Abstract Background Salmonella infections are associated with gastroenteritis, enteric fever, bacteremia, focal infection, and chronic carrier state. Cases of Salmonella osteomyelitis are uncommon and mainly occur in individuals with immunosuppressive conditions. Herein, we report a case of Salmonella osteomyelitis that required differentiation from malignancy in an immunocompetent adult patient. Case presentation A 31-year-old previously healthy male truck driver presented with a 2-week history of pain in his left upper arm. He had fallen off the back of a truck 2 months previously and injured the left side of his body. He also had bloody diarrhea and fever. Computed tomography and magnetic resonance imaging revealed a lesion that appeared to be a bone tumor in the left humerus, and the patient was referred to our cancer center from another clinic. Culture of a biopsy specimen of the left humerus was negative; however, the consensus sequence in broad-range polymerase chain reaction (PCR) showed the highest similarity to the 16S rRNA gene of Salmonella enterica subspecies enterica. Curettage of the left humerus was performed, and the patient was administered levofloxacin for 6 weeks. He recovered left arm function and had no recurrence during 2 months of follow-up. Conclusions When the culture of blood or biopsy specimens is negative in situations wherein a specific infection is suspected, broad-range PCR with sequencing should be considered to determine the causative organism.