Beyond COL1A1::PDGFB: Rare fusions and their clinical implications in dermatofibrosarcoma protuberans

Table 1 Clinicopathological and therapeutic correlation of gene fusions reported in dermatofibrosarcoma protuberans

Fusion	Key clinicopathological profile	Sensitivity to targeted therapy
COL1A1::PDGFB	Classic DFSP morphology (m/c location extremities), fibrosarcomatous DFSP	Excellent sensitivity to imatinib
COL1A2::PDGFB	Classic DFSP morphology (m/c location extremities), fibrosarcomatous DFSP	Excellent sensitivity to imatinib
COL6A3::PDGFD	Classic DFSP in female (m/c location breast), less aggressive course and better survival	Strong sensitivity to imatinib
EMILIN2::PDGFD and EMILIN1::PDGFD	Seen in superficial skin of extremities (EMILIN2 fusion), EMILIN1 fusion very recently described	Presumed to be similar to other PDGFD fusion
TNC::PDGFD	Fibrosarcomatous DFSP	Therapeutic sensitivity is under investigation, likely imatinib sensitive via PDGFB pathway
FBN1::CSAD	Fibrosarcomatous DFSP, clinicopathological features are unexplored and require more research	Involvement of alternate molecular pathogenesis, imtaninib sensitivity yet to be explored
MAP3K7CL::ERG	Fibrosarcomatous DFSP, clinicopathological features are unexplored and require more research	Involvement of alternate molecular pathogenesis, imtaninib sensitivity yet to be explored
SLC2A5::BTBD7	Recently described fusion, clinicopathological features are unexplored and require more research	Involvement of alternate molecular pathogenesis, imtaninib sensitivity yet to be explored
LARGE1::PRKCA	Recently described fusion, clinicopathological data yet to be explored	Very recently described fusion, therapeutic sensitivity yet to be explored

DFSP: Dermatofibrosarcoma protuberans; m/c: Most common; EMILIN1: Elastin microfibrillar interface protein 1; EMILIN2: Elastin microfibrillar interface protein 2; PDGFD: Platelet-derived growth factor-D; PDGFB: Platelet-derived growth factor-B.