CRTC1-TRIM11 Fusion in a Case of Metastatic Clear Cell Sarcoma: Are CRTC1-TRIM11 Fusion-bearing Tumors Melanocytomas or Clear Cell Sarcomas?

Are CRTC1-TRIM11 Fusion-bearing Tumors Melanocytomas or Clear Cell Sarcomas? To the Editor: We read with interest the article by Cellier and colleagues in the 2018 March issue of the American Journal of Surgical Pathology on the proposal of a new tumor entity named cutaneous melanocytoma with CRTC1-TRIM11 fusion, which seems to have a favorable prognosis.1 The authors reported 5 cases of unpigmented nodular dermal tumors, which harbored a previously undescribed invariable CRTC1-TRIM11 fusion highlighted with RNA sequencing (t(19;1)(p13;q42)). These tumors displayed a unique nodular pattern with dense fascicles and nests of unpigmented cells with medium to large atypical epithelioid and spindle cells, with constant expression of melanocytic markers (SOX10, MelanA, S100 protein, and HMB45), resembling dermal clear cell sarcoma (CCS). In some cases, necrosis and a high mitotic activity were observed. However, none of the 5 cases recurred during a median follow-up of 14 months (3 to 72 mo). On the basis