[A tumour mistaken for a scar]

Dermatofibrosarcoma protuberans (DFSP) is a rare type of cutaneous soft tissue sarcoma. The tumour metastasises rarely, but the percentage of recurrences is high and the tumour can be locally very aggressive.

A 50-year-old man was referred to our clinic for a long existing scar on his back, which had become painful in the last few weeks. In the hospital we decided to take a biopsy. Based on the histopathological investigation, the diagnosis DFSP was made. The patient was referred to a tertiary centre specialising in rare skin malignancies.

DFSP is clinically heterogeneous with the consequence that several differential diagnoses can be made. Histopathological examination is the gold standard diagnostic approach when there is a possible suspicion of DFSP. Because of the aggressiveness and the high recurrence rate it is very important to make a timely diagnosis, to allow appropriate treatment - preferably radical excision - to take place.