Pseudocystic dermatofibrosarcoma protuberans: report of two cases and demonstration of COL1A1-PDGFB rearrangement.

We report two unique cases of dermatofibrosarcoma protuberans (DFSP) that included a pseudocystic component. Molecular analysis of one of the cases showed a characteristic COL1A1-PDGFB rearrangement in both the main tumor and also in the cells lining the pseudocystic portion of the tumor, confirming the diagnosis and indicating that the lining represented a component of the proliferation. It is important to raise awareness of this rare variant within the varied spectrum of DFSP. Shvartsbeyn M, Lazar AJF, Lopez-Terrada D, Meehan SA. Pseudocystic dermatofibrosarcoma protuberans: report of two cases and demonstration of COL1A1-PDGFB rearrangement.