Soft tissue
Uncertain differentiation
Phosphaturic mesenchymal tumor
Authors: Vijay Shankar, M.D., Nat Pernick, M.D.
Last author update: 1 November 2012
Last staff update: 11 January 2023
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Phosphaturic mesenchymal tumor
Table of Contents
Definition / general | Epidemiology | Laboratory | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosisCite this page: Shankar V. Phosphaturic mesenchymal tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuephosphaturic.html. Accessed April 19th, 2024.
Definition / general
- Benign tumor of bone or soft tissue associated with rickets and osteomalacia (Am J Surg Pathol 1989;13:588)
- Most cases of tumor associated oncogenic osteomalacia are due to phosphaturic mesenchymal tumor, which produces fibroblast growth factor-23, a protein that inhibits renal tubular phosphate reabsorption or dentin matrix protein 1, causing low serum phosphate and resulting oncogenic osteomalacia; also low serum 1,25 dihydroxyvitamin D (Am J Surg Pathol 2004;28:1, Mod Pathol 2004;17:573, Pediatr Dev Pathol 2000;3:61)
Epidemiology
- Extremely rare, median age 53 years, range 9 - 80 years, slight female predominance
Laboratory
- Low serum phosphate, renal phosphate wasting, low 1,25-dihydroxy Vitamin D3
Case reports
- 22 year old man with tumor of craniofacial sinuses (Clin Cases Miner Bone Metab 2011;8:45)
- 36 year old woman with muscle pain and weakness (Arch Pathol Lab Med 2002;126:1245)
- 42 year old woman with tumor of ethmoid sinus (Indian J Pathol Microbiol 2010;53:384)
- 42 year old woman with mandible tumor (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:925)
- 45 year old man with mixed connective tissue varian (Intern Med 2006;45:1157)
- 53 year old man with a pretribial mass (Case of the Week #63)
Treatment
- Complete excision causes dramatic reversal of signs and symptoms (Am J Surg Pathol 1989;13:588)
Clinical images
Images hosted on other servers:
Tumor of ethmoid sinus
Gross description
- 2 - 14 cm, arises in soft tissue and bone
Microscopic (histologic) description
- Hypocellular tumor of bland spindle cells with small nuclei, indistinct nucleoli
- Has hemangiopericytoma-like vasculature, osteoclast-like giant cells, distinctive grungy calcified matrix, fat, microcysts, hemorrhage, incomplete rim of membranous ossification, metaplastic bone
- Infiltrative
- No / rare mitotic activity, no atypia
- Malignant cases: rare cases with nuclear atypia, 5+ mitotic figures / 10 HPF, high cellularity, resembles MFH
Microscopic (histologic) images
Contributed by Sharon Bihlmeyer, M.D. (Case #63) and AFIP
Various images
Giant cells
Images hosted on other servers:
Tumor of craniofacial sinuses
Tumor of ethmoid sinus
Mandible tumor
Positive stains
- Fibroblast growth factor-23 (Am J Surg Pathol 2004;28:1)
- Dentin matrix protein 1 (Mod Pathol 2004;17:573)
Differential diagnosis
