Xanthogranulomatous osteomyelitis | |
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Other names | XO |
Specialty | Infectious disease, orthopedic |
Xanthogranulomatous osteomyelitis is a peculiar aspect of osteomyelitis characterized by prevalent histiocytic infiltrate and foamy macrophage clustering.[1]
See also: Xanthogranulomatous inflammation |
The granulomatous tissue largely comprises foam cells of monocyte/macrophage origin positive for KP1, HAM56, CD11b and CD68. Neutrophils, hemorrhagic foci and numerous plasma cells are additional findings.[2][3][4][5] Staphylococcus aureus was isolated in the case reported by Kamat et al.[5] A delayed type hypersensitivity reaction in cell-mediated immunity has been suggested in this type of infiltrate that is composed of macrophages and T cells.[3] T cells are represented by a mixture of CD4+ and CD8+ lymphocytes. Macrophages and lymphocytes show marked expression of HLA-DR antigen.[6] Arguably XO is the bone localization of the xanthogranulomatous process occurring in several other locations.[2]
As of 2011 five cases had been reported, involving rib, tibial epiphysis, ulna, distal tibia and femur. Young individuals are prevalently affected but one case involved a 50-year-old woman. Pain, swelling of possibly long duration, fever and increased ESR are some of the main clinical findings. X-ray examination shows lytic foci with sclerotic margins.[2][3][4][5]
Antibiotics have been used with success for cases with positive cultures, Curettage, bone grafting, and resection has been described in few studies.[7][8]