title: Phosphaturic mesenchymal tumor-induced rickets.
abstract: We describe two prepubertal girls with oncogenic rickets. The first patient, 9 years of age, presented with recent-onset lower-extremity pain. The second girl, presented at 4 years of age following a 9-month period of muscle weakness, bone pain, and poor linear growth. Laboratory analyses in both patients revealed hypophosphatemia and hyperphosphaturia; elevated circulating alkaline phosphatase activity was present in one of them. Radiographic evidence of a generalized rachitic process was evident in both cases. Computerized tomography of the paranasal sinuses and facial bones in patient 1 revealed a small lesion eroding through the inner table of the left mandibular ramus. Microscopic examination of this mass revealed a spindle cell neoplasm with chondroid material, dystrophic calcification, and both osteoclast-like and fibroblast-like cells. Prominent vascularity and marked atypia were present. These features are consistent with a phosphaturic mesenchymal tumor of the mixed connective tissue variant. In the second patient, computerized tomography revealed a lytic lesion located in the right proximal tibia, with histologic features consistent with a phosphaturic mesenchymal tumor of the nonossifying fibroma-like variant. Resection of each tumor resulted in rapid correction of the phosphaturia and healing of the rachitic abnormalities. A careful search for small or occult tumors should be carried out in cases of acquired phosphaturic rickets.
authors.affiliation: Department of Pathology, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06520, USA.
authors.forename: M
authors.initials: M
authors.lastname: Reyes-Múgica
authors.forename: S L
authors.initials: SL
authors.lastname: Arnsmeier
authors.forename: P F
authors.initials: PF
authors.lastname: Backeljauw
authors.forename: J
authors.initials: J
authors.lastname: Persing
authors.forename: B
authors.initials: B
authors.lastname: Ellis
authors.forename: T O
authors.initials: TO
authors.lastname: Carpenter
mesh_terms: D001859:Bone Neoplasms / Q000150:complications / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000209:etiology*; D008339:Mandibular Neoplasms / Q000150:complications / Q000652:urine; D008637:Mesenchymoma / Q000150:complications* / Q000652:urine*; D010755:Organophosphates / Q000652:urine*; D010018:Osteomalacia / Q000209:etiology*
chemical_list: D010755:Organophosphates