Pathology: calcified chondroid mesenchymal neoplasm

Lobulated; spindle-epithelioid cells with patternless distribution

Pale amphophilic cytoplasm

Round-ovoid nuclei with vesicular chromatin, mild atypia, occasional binucleation; inconspicuous mitotic activity

Chondromyxoid stroma with 'grungy' calcification and foreign-body giant cells; trabeculae of woven bone with osteoblastic rimming

RNA-seq: FN1::FGFR2 gene fusion

Lobulated; hypocellular; spindle-epithelioid cells with patternless distribution

Pale amphophilic cytoplasm

Round-ovoid nuclei with vesicular chromatin, mild atypia, occasional binucleation

Chondromyxoid stroma with 'grungy' calcification and foreign-body giant cells

RNA-seq: FN1::FGFR2 gene fusion

Lobulated; hypocellular

Spindle-epithelioid cells with pale amphophilic cytoplasm 

Round-ovoid nuclei with vesicular chromatin, mild atypia, occasional binucleation

Chondromyxoid stroma with 'grungy' calcification and foreign-body giant cells

IHC: D2-40, ERG, S100

RNA-seq: FN1::FGFR2 gene fusion

PMID:  33727696

Lobulated; hypocellular; spindle-epithelioid cells with patternless distribution

Pale amphophilic cytoplasm with indistinct cell borders

Monomorphic ovoid nuclei; inconspicuous mitotic activity

Cartilaginous matrix with so-called "grungy" calcification; interspersed osteoclast-type giant cells

IHC: ERG, D2-40

RNA-seq: FN1::FGFR2 gene fusion

PMID: 33727696 

Lobulated; hypocellular; spindle-epithelioid cells with patternless distribution

Pale amphophilic cytoplasm with indistinct cell borders

Monomorphic ovoid nuclei; inconspicuous mitotic activity

Cartilaginous matrix with so-called "grungy" calcification; interspersed osteoclast-type giant cells

RNA-seq: FN1::FGFR1 gene fusion

PMID: 33727696 

Lobulated; hypocellular; spindle-epithelioid cells with patternless distribution

Pale amphophilic cytoplasm with indistinct cell borders

Monomorphic ovoid nuclei with occasional binucleation; inconspicuous mitotic activity

Cartilaginous matrix with so-called "grungy" calcification; interspersed osteoclast-type giant cells

IHC: D2-40