Details

Autor(en) / Beteiligte

• Cohen, Jarish N.
• Sabnis, Amit J.
• Krings, Gregor
• Cho, Soo-Jin
• Horvai, Andrew E.
• Davis, Jessica L.

Titel

EWSR1-NFATC2 gene fusion in a soft tissue tumor with epithelioid round cell morphology and abundant stroma: a case report and review of the literature

Ist Teil von

• Human pathology, 2018-11, Vol.81, p.281-290

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2018

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Mesenchymal round cell tumors are a diverse group of neoplasms defined by primitive, often high-grade cytomorphology. The most common molecular alterations detected in these tumors are gene rearrangements involving EWSR1 to one of many fusion partners. Rare EWSR1-NFATC2 gene rearrangements, corresponding to a t(20;22) gene translocation, have been described in mesenchymal tumors with clear round cell morphology and a predilection for the skeleton. We present a case of a tumor harboring the EWSR1-NFATC2 gene fusion arising in the subcutaneous tissue of a young woman. The tumor exhibited corded and trabecular architecture of epithelioid cells within abundant myxoid and fibrous stroma. The cells showed strong immunoreactivity for NKX2.2, variable CD99, keratin, and epithelial membrane antigen, but were negative for S100 and myoepithelial markers. Importantly, similar to previously reported cases, the clinical course was more indolent than that of Ewing sarcoma. This case highlights the distinctive clinicopathological characteristics of EWSR1-NFATC2 gene fusion–associated neoplasms that distinguish them from Ewing sarcoma. •The EWSR1-NFATC2 fusion tumor we describe is the first to be reported in a woman and only the second reported to arise in soft tissue.•The EWSR1-NFATC2 fusion tumor we describe had epithelioid clear and round cell morphology and was arranged in cords and thin trabeculae within abundant fibrous and myxoid stroma.•As a group, EWSR1-NFATC2 fusion tumors have variable positive staining for CD99, keratin, and EMA, and do not express myoepithelial markers.•As a group, EWSR1-NFATC2 fusion tumors behave in a more clinically indolent manner than typical Ewing sarcoma.•EWSR1-NFATC2 fusion tumors may represent a group of mesenchymal tumors distinct from Ewing sarcoma.