Bone histomorphometric and immunohistological analysis for hyperostosis in a patient with SAPHO syndrome: A case report
Shun Watanabe,
Naoki Sawa,
Hiroki Mizuno,
Rikako Hiramatsu,
Noriko Hayami,
Masayuki Yamanouchi,
Tatsuya Suwabe,
Junichi Hoshino,
Takeshi Fujii,
Toshihide Hirai,
Tomoka Hasegawa,
Norio Amizuka,
Yoshifumi Ubara
Affiliations
Shun Watanabe
Nephrology Center, Toranomon Hospital, Kanagawa, Japan; Corresponding authors at: Nephrology Center, Toranomon Hospital, Kajigaya, 1-3-1, Takatsu, Kawasaki, Kanagawa 213-0015, Japan.
Naoki Sawa
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Hiroki Mizuno
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Rikako Hiramatsu
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Noriko Hayami
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Masayuki Yamanouchi
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Tatsuya Suwabe
Nephrology Center, Toranomon Hospital, Kanagawa, Japan
Junichi Hoshino
Nephrology Center, Toranomon Hospital, Kanagawa, Japan; Okinaka Memorial Institute for Medical Research, Toranomon Hospital, Tokyo, Japan
Takeshi Fujii
Department of Pathology, Toranomon Hospital, Tokyo, Japan
Toshihide Hirai
Department of Orthopaedic Surgery and Spinal Surgery, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
Tomoka Hasegawa
Hard Tissue Developmental Biology Department Graduate School of Dental Medicine and Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan
Norio Amizuka
Hard Tissue Developmental Biology Department Graduate School of Dental Medicine and Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan
Yoshifumi Ubara
Nephrology Center, Toranomon Hospital, Kanagawa, Japan; Okinaka Memorial Institute for Medical Research, Toranomon Hospital, Tokyo, Japan; Corresponding authors at: Nephrology Center, Toranomon Hospital, Kajigaya, 1-3-1, Takatsu, Kawasaki, Kanagawa 213-0015, Japan.
A 56-year-old Japanese woman with a history of palmoplantar pustulosis was admitted for examination due to left femur pain. Radiography and computed tomography showed thickening of the bone on the outer portion of the left femur. Bone scintigraphy of the left femur showed intense radioactive uptake. Consequently, the patient was diagnosed with SAPHO syndrome. Bone histomorphometric analysis of the left femur showed cancellous bone with thickened cortical bone. Whilst normal bone shows cancellous bone with double labeling (normal turn over), and cortical bone with no labeling (low turn over, adynamic state), this case presented with both cancellous and cortical bone with marked double labeling (indicating high turn over), abundant osteoid and woven bone. Immunohistological analysis showed that cells lining the bone surface consisted of osteoblasts and were positive for alkaline phosphatase (ALP). Few to little of these cells were positive for tartrate-resistant acid phosphatase (TRAP)-5B, cathepsin K and matrix metallopeptidase 9 (MMP-9). These results indicate that, in this case study, excessive production of osteoblasts contributed to hyperostosis of the left femur, with abundant osteoid and woven bone. This type of bone formation in SAPHO syndrome is not lamellar bone seen in normal bone, but rather fragile and mechanically weak bone, resulting in bone pain. Doxycycline may be a therapeutic option for bone pain in this patient.