EWSR1-SMAD3-rearranged Fibroblastic Tumor: An Emerging Entity in an Increasingly More Complex Group of Fibroblastic/Myofibroblastic Neoplasms.

摘要: Three cases of superficial acral fibroblastic spindle cell neoplasms with EWSR1-SMAD3 fusion have been recently reported. Their differential diagnosis is broad, primarily comprising rare tumors from the fibroblastic/myofibroblastic category. The aim this report to present 4 new entity and discuss appropriate diagnosis. Also, as ERG antibody seems be a characteristic marker for these tumors, we analyzed immunostaining characteristics in potential mimics entity. All our cohort occurred women aged 5 68 years (mean, 36.5 y). Two were located on hand, 1 foot, last case arose calf. tumor size ranged 1.5 cm greatest dimension, mean 1.2 cm. Except one recent case, follow-up was available, ranging 7 18 11.7 y), recurrence noted after 10 years. subcutaneous showed 2 main components. One consisted bland, spindled cells elongated nuclei which round when observed cross-section. These mostly grew relatively hypercellular, well-organized, intersecting fascicles. second component prominently hyalinized paucicellular, but lacked calcifications. Both components either distinct zonation pattern, or they randomly intermingled each other. In all 3 analyzable next-generation sequencing gene case. By fluorescence situ hybridization, tested also revealed unbalanced rearrangement EWSR1 gene. strong, diffuse nuclear expression ERG, whereas none stained except weak moderate staining calcifying aponeurotic fibromas (9/10 cases). focal SAT-B2. herein presented further broaden clinicopathologic spectrum fusion. They confirm that represent novel propose name EWSR1-SMAD3-rearranged Tumor. Our study proves context immunohistochemistry specific neoplasms.