Soft Tissue Tumours Flashcards
(20 cards)
What clinical scenario can result from phosphaturic mesenchymal tumour?
Tumour induced osteomalacia
What tumour can cause tumour induced osteomalacia?
Phosphaturic mesenchymal tumour
What is the mechanism of tumour induced osteomalacia in phosphaturic mesenchymal tumour?
Production of FGF23 which is a phosphaturic hormone that inhibits renal proximal tubule phosphate reuptake, leading to severe hypophosphatemia
What enzyme is produced in phosphaturic mesenchymal tumour?
FGF23
What is the cell of origin/differentiation of phosphaturic mesenchymal tumour?
Uncertain differentiation
What is the molecular basis of phosphaturic mesenchymal tumour?
Fusion of FN1-FGFR1 or FN1-FGF1 (rarely), leading to production of FGF23
What does FGF23 stand for?
Fibroblast growth factor 23
What processes is fibroblast growth factor 23 involved in?
Phosphate and vitamin D metabolism and regulation
Where does phosphaturic mesenchymal tumour occur?
Soft tissue and bone
Where does phosphaturic mesenchymal tumour usually not occur?
Retroperitoneum/viscera/mediastinum
Who does phosphaturic mesenchymal tumour usually occur in?
Middle aged adults
What proportion of phosphaturic mesenchymal tumours bear a characteristic gene fusion?
Almost 50%
What marker is expressed in most phosphaturic mesenchymal tumours regardless of fusion status?
FGFR1
FGFR1 is expressed rarely in phosphaturic mesenchymal tumour, true or false?
False (common, regardless of fusion status)
What are the possible macro appearances of phosphaturic mesenchymal tumour?
Non-specific, with calcs, with fat
What tumour features: - bland spindled fibrohistiocytic cells - smudgy hyaline matrix - capillary network with possible stag horn vessels with pericytoma features - grungy/flocculent calcs, maybe slate grey flower like crystals - primitive cartilage or osteoid - osteoclasts - fat - microcystic change - peripheral shell of woven bone - no mitosis or necrosis usually
Phosphaturic mesenchymal tumour
What are the histologic features of phosphaturic mesenchymal tumour?
- bland spindled fibrohistiocytic cells - smudgy hyaline matrix - capillary network with possible stag horn vessels with pericytoma features - grungy/flocculent calcs, maybe slate grey flower like crystals - primitive cartilage or osteoid - osteoclasts - fat - microcystic change - peripheral shell of woven bone - no mitosis or necrosis usually
Are phosphaturic mesenchymal tumours benign or malignant?
Benign (but can have malignant ones)
What are the features of malignant phosphaturic mesenchymal tumour?
High grade nuclear features, invasion, recurrence (look like undiff pleomorphic sarcoma or fibrosarcoma)
What does this image show? Which tumour is it characteristic of?
Grungy calcifications in phosphaturic mesenchymal tumour
