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