Single-cell RNA profiling of the primary tumor and metastatic lymph node lesions in a patient with clear cell sarcoma of soft tissue: A case report

There was no report which evaluated the cellular constitution and cell–cell interactions in clear cell sarcoma of soft tissue. A 47-year-old woman underwent surgical excision of clear cell sarcoma in right knee and inguinal lymph node metastasis after neo-adjuvant chemotherapy. However, she died due to liver and para-aortic lymph node metastasis. Single-cell RNA sequencing of the primary tumor and metastatic lymph node samples revealed the accumulation of CTLA4+/CD4+ regulatory and LAG3+/CD8+ exhausted T cells particularly in the metastatic lymph node. NicheNet analysis indicated that these T cell states were induced by the interplay of T cells with tumor cells, macrophages, B cells, fibroblasts, and endothelial cell. The cellular constitution of immune and stromal cell types and their properties suggested the presence of T cell immunosuppression in the clear cell sarcoma microenvironment.