Adolescent Superficial CD34-Positive Fibroblastic Tumor With Unique IHC Profile

Superficial CD34-positive fibroblastic tumor (SCD34FT) is a relatively uncommon soft tissue neoplasm, first identified in 2014 and included in the latest, fifth edition of the World Health Organization Soft Tissue and Bone Tumors Classification. A subset of SCD34FTs that exhibit PRDM10 rearrangement may overlap with other PRDM10-rearranged soft tissue tumors, suggesting a shared pathogenic pathway. We report a case of a 16-year-old patient, one of the youngest diagnosed, with an SCD34FT on the forearm, featuring both PRDM10 rearrangement and a unique, diffuse expression of cytokeratin (CK AE1/AE3). This case contributes to the expanding literature on SCD34FT, highlighting its clinical and pathological diversity.