Update on Cutaneous Soft Tissue Tumors.

This article focuses on various recently described or emerging cutaneous soft tissue neoplasms. These entities encompass a wide range of clinical and histologic characteristics. Emphasis is placed on their distinguishing morphologic and immunophenotypic features compared with entities that enter into their differential diagnosis, as well as novel immunophenotypic and molecular tests that are often necessary for accurate diagnosis of these entities. Entities discussed include EWSR1-SMAD3-rearranged fibroblastic tumor, superficial CD34-positive fibroblastic tumor, epithelioid fibrous histiocytoma, CIC-rearranged sarcomas, and NTRK-rearranged spindle cell tumors.