A Rare Case of Xanthogranulomatous Osteomyelitis of Proximal Femur Managed with Two-stage Total Hip Arthroplasty

Xanthogranulomatous osteomyelitis (XO), first described by Cozzuto in 1984, is characterized histopathologically by prominent foamy macrophages. Xanthogranulomatous infection commonly affects the gall bladder and kidney, but involvement of bone is extremely rare. To date, only 15 cases of XO have been reported. We present the 16th case in a 24-year-old male who presented with a lytic lesion in the left hip. Radiological evaluation suggested an infective etiology, either pyogenic or tubercular, but histopathology confirmed xanthogranulomatous osteomyelitis of the left proximal femur. The patient was managed with a two-stage surgical approach: stage 1 involved excision arthroplasty with placement of an antibiotic-loaded cement spacer and stimulan beads, followed by stage 2 uncemented total hip arthroplasty. Histopathological examination revealed sheets of foamy histiocytes with scattered plasma cells and lymphocytes. This case is reported due to its rarity and to highlight the importance of considering XO in the differential diagnosis of lytic bone lesions.