title: Occurrence of new bone-like tissue formation in uremic tumoral calcinosis.
abstract: A 55-year-old woman who had been on hemodialysis for 5years was admitted for evaluation of a hard mass in the right hip region. Her serum calcium (Ca)-phosphate (P) product was elevated. Radiographs showed periarticular calcified masses in the soft tissues around both hips and shoulders, which were characteristic of uremic tumoral calcinosis (UTC). Biopsy specimens were obtained from both right hip mass and the right iliac crest. Histological examination of hip mass revealed bone-like tissue with marrow, as well as calcified material. The bone-like tissue was categorized as heterotopic ossification (HO), because it had been formed inside soft tissue where bone-like tissue does not normally exist. Histological analysis of HO showed the formation of cancellous bone-like tissue. Woven mineralized bone-like tissue was predominant over lamellar bone-like tissue. High bone turnover combined with osteitis fibrosa-like lesion was diagnosed because of an increase of the fibrous volume, as well as clear double tetracycline labeling. Near a site of HO, numerous ALP- and Runx2-positive cuboidal osteoblast-like cells and TRAP- and cathepsin K-positive multinucleated osteoclast-like cells were noted. Histomorphometric analysis of the right iliac crest revealed osteitis fibrosa. This is the first report of HO in a patient with UTC. After parathyroidectomy, the patient's Ca-P imbalance was corrected and UTC subsided. Although the mechanism by which new bone-like tissue formation arises in the soft tissues has not yet been determined, secondary hyperparathyroidism may have contributed to the progression of UTC in this patient.
authors.affiliation: Nephrology Center, Toranomon Hospital, Tokyo, Japan.
authors.forename: Rikako
authors.initials: R
authors.lastname: Hiramatsu
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Ubara
authors.forename: Noriko
authors.initials: N
authors.lastname: Hayami
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamanouchi
authors.forename: Eiko
authors.initials: E
authors.lastname: Hasegawa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Sumida
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Suwabe
authors.forename: Junichi
authors.initials: J
authors.lastname: Hoshino
authors.forename: Naoki
authors.initials: N
authors.lastname: Sawa
authors.forename: Norio
authors.initials: N
authors.lastname: Amizuka
authors.forename: Kenmei
authors.initials: K
authors.lastname: Takaichi
mesh_terms: D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D009999:Ossification, Heterotopic / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D010012:Osteogenesis; D010388:Pelvis / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D014511:Uremia / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*