Dermatofibrosarcoma protuberans with atrophic appearance at early stage of the tumor.

We report a case of dermatofibrosarcoma protuberans (DFSP) which had looked like an atrophic plaque on the face for 20 years and been diagnosed as morphea. At the late stage after subsequent development of a nodule, histopathological examinations including immunohistochemical stainings revealed the final diagnosis of DFSP. While DFSP is given typical "protuberant" morphology, our case indicates that DFSP sometimes appears as a non-protuberant lesion. Some reported variants of non-protuberant DFSP are suspected to be preceding features at the early stage of DFSP before the protuberant feature occurs. We should take this preprotuberant stage of DFSP into consideration of different diagnoses with non-protuberant lesions. Histopathological examination and immunohistochemical stainings are necessary for an accurate and early diagnosis of DFSP.