Immunohistochemical Expressions of D2-40, CD34, and Factor XIIIa between Dermatofibroma and Dermatofibrosarcoma Protuberance

Choi, Jin Hwa; Kim, Byeong Su; Kim, Yeon Woong; Kim, Joon Goon; Shin, Dong Hoon; Choi, Jong Soo; Bae, Young Kyung

Abstract

BACKGROUND
Dermatofibrosarcoma protuberance (DFSP) must be differentiated from dermatofibroma (DF). However, especially in cases of superficial biopsy and cellular dermatofibroma, this is difficult by using histopathology alone since both are composed of neoplastic spindle cells. Although a panel of immunostains is useful, the expressions of conventional markers often overlap. A previous study showed that novel D2-40 immunostain may be useful for differentiating between DF and DFSP.
OBJECTIVE
To evaluate the usefulness of D2-40 immunohistochemical staining for differentiating DFSP from DF and compare the results with other commonly used immunostains (CD34 and factor XIIIa).
METHODS
Twenty-eight cases of DF and 15 cases of DFSP were selected from clinicopathologically proven cases reviewed by the Department of Dermatology at our medical center and Daegu Catholic University Medical Center. D2-40, CD34, and factor XIIIa immunohistochemical staining was performed. The immunopositivity was measured throughout the entire lesion.
RESULTS
Seventeen cases (60.7%) of DF and no cases of DFSP showed immunoreactivity to D2-40 in the spindle cells. Three (10.7%) cases of DF and 13 (86.7%) cases of DFSP showed immunoreactivity to CD34 in the spindle cells. Twenty-five (89.3%) cases of DF and four (26.7%) cases of DFSP showed immunoreactivity to factor XIIIa in the spindle cells. A total of 60.7% of cases of DF were positive on D2-40 staining, 89.3% were negative on CD34 staining, and 89.3% were positive on factor XIIIa staining. All cases (100%) of DFSP were negative by D2-40 staining, 86.7% were positive by CD34 staining, and 73.3% were negative by factor XIIIa staining.
CONCLUSION
D2-40 immunostaining may be useful for distinguishing between DF and DFSP since the immunoreactivity of DF was significantly higher than that of DFSP (p=0.001). However, the results of our study were not as useful as those of a previous study. Therefore, further studies are needed to address this issue.