Dermatofibrosarcoma protuberans (DFSPs) are uncommon skin tumors that have a high incidence of local recurrence even with wide surgical margin, but DFSPs rarely metastasize. Previous reports have suggested that DFSPs may enlarge more rapidly during pregnancy. We report 3 additional cases of DFSPs that showed accelerated growth during pregnancy. Immunohistochemical stains for CD34, S-100 protein, factor XIIIa, and estrogen and progesterone receptors were performed on biopsy specimens. The tumors in all 3 patients, and 4 additional DFSPs from 2 male and 2 female subjects, showed expression of progesterone receptor. As with many other stromal neoplasms, DFSPs appear to express low levels of hormone receptors, which may be one factor that accounts for their accelerated growth during pregnancy.