Download - DSS 2010-1
DSS 2010-1DSS 2010-1
Sarah E. Martin, M.D.Eyas M. Hattab, M.D.
Indiana University School of Medicine86th Annual Meeting of the AANP
June 10-13, 2010
Clinical HistoryClinical History
61 yo woman with a history of multiple fractures and hypophosphatemia for 6 yrs
Presented with bilateral weakness and shooting pains in her legs after a fall
MRI: multi-lobulated, vividly enhancing, heterogeneous T12 mass with extension into epidural space and paraspinal musculature
Diagnosis?Diagnosis?
Phosphaturic mesenchymal Phosphaturic mesenchymal tumor, mixed connective tissue tumor, mixed connective tissue
variant (PMTMCT)variant (PMTMCT)
PMTMCTPMTMCT
Definition– Largely benign, morphologically distinct
mesenchymal neoplasm almost invariably associated with oncogenic osteomalacia
Incidence– Extremely rare, ~ 150 cases described in the
literature
Historical perspective– 1987: Weidner and Santa Cruz coined term
– 2004: Folpe et al. fully characterized PMTMCT
PMTMCTPMTMCT Location
– Soft tissues and bones of the extremities
– Only rarely in axial skeleton (index case)
Etiology
– FGF-23 overexpression: inhibits trans-epithelial phosphate transport in renal tubules, resulting in renal phosphate wasting and subsequent osteomalacia
Clinical features:
– 25-77 years; female predominance
– Bone pain, multiple fractures
– Hypophosphatemia, hyperphosphaturia, and osteomalacia; fail vitamin D therapy
– Chronic, protracted history before tumor is discovered
PMTMCT: pathologyPMTMCT: pathology Gross:
– Superficial and deep soft tissues– Well-circumscribed
Microscopic – Low cellularity, bland spindled cells– Myxochondroid/osteoid-like matrix– Dystrophic calcification, incomplete rim of ossification – HPC-like vessels, microcysts, hemorrhage– Osteoclast-like giant cells
Immunohistochemistry – FGF-23
PMTMCT: pathologyPMTMCT: pathology Differential diagnosis:
– Hemangiopericytoma– Giant cell tumor– Osteoblastoma– Osteosarcoma– Mesenchymal chondrosarcoma– Hemangioma
Keys to diagnosis:– Awareness of entity– Clinical history of osteomalacia (not universal)– Morphologic heterogeneity
PMTMCT: managementPMTMCT: management Treatment
– Surgical resection is curative of both tumor and osteomalacia
Prognosis– Generally excellent after complete resection– Rare malignant forms have been reported
Increased mitoses, high nuclear grade and high cellularity
Local recurrence; lung and skeletal metastases reported
The end.The end.