Dermatofibrosarcoma protuberans (DFSP) is a hypercellular, storiform, CD34+ low-grade sarcoma with honeycomb entrapment of fat, which typically involves the trunk and extremities.

Differential diagnosis:

 dermatofibroma (fibrous histiocytoma)(CD34, Factor XIIIa, CD44, hyaluronate) (#12641778#)

Variants

 occurence in a smallpox vaccination scar (#12734474#)
 congenital dermatofibrosarcoma protuberans (#12588227#)
 pigmented dermatofibrosarcoma protuberans (Bednar tumor)
 superficial adult fibrosarcoma with COL1A1/PDGFB fusion transcript expression

Cytogenetics

 translocation t(17;22)(q22;q13) creating COL1A1/PDGFB fusion gene
 translocation t(9;22)(q32;q12.2)
 translocation t(2;17)

Molecular biology

 COL1A1/PDGFB fusion protein by t(17;22)(q22;q13) (COL1A1 at 17q22 and PDGFB at 22q13

 genic amplification

• 17q (#11435686#)
• 22q (#11435686#)

Localization

 cutaneous DFSP
 oral DFSP (#10534672#)
 labial DFSP (#9236907#)
 jejeunal DFSP (#11206873#)

Spradic ssociations

 nuchal-type fibroma (#14675287#)

References

 Takahira T, Oda Y, Tamiya S, Yamamoto H, Kawaguchi K, Kobayashi C, Oda S, Iwamoto Y, Tsuneyoshi M. Microsatellite instability and p53 mutation associated with tumor progression in dermatofibrosarcoma protuberans. Hum Pathol. 2004 Feb;35(2):240-5. PMID: #14991543#

 Kahn HJ, Fekete E, From L. Tenascin differentiates dermatofibroma from dermatofibrosarcoma protuberans: comparison with CD34 and factor XIIIa. Hum Pathol. 2001 Jan;32(1):50-6. PMID: #11172295#