ABSTRACT
Objective:To investigate the values of immunophenotype and the Collagen type1 alpha1/Proto-oncogene Proteins c-sis (COL1A1/PDGFB) fusion gene in the diagnosis of dermatofibrosarcoma protuberans (DFSP). Methods:IHC markers and the COL1A1/PDGFB fusion gene were detected by IHC staining and interphase fluorescence in situ hybridization (FISH) in 73 cases previously diagnosed as DFSP. A total of 85 and 10 non-DFSP cases were also included as controls for IHC staining and FISH, respectively. Results:In the 73 DFSP cases, the positive detection rates for immunohistochemical marker vimentin, CD34, CD99, S100, desmin and SMA were 100%, 91.78%, 61.64%, 0, 0, and 6.85%, correspondingly. Protein expression levels in these cases varied from the control group, and CD34 ex-pression was significantly different among the differential diagnoses. The positive detection rate for the COL1A1/PDGFB fusion gene was 86.96%(60/69), whereas the gene expression in the control group was negative. Conclusion:The COL1A1/PDGFB fusion gene is a highly specific and sensitive marker in the diagnosis of DFSP. CD34 is a suitable marker for DFSP.