A rare synovial sarcoma of the kidney exhibiting translocation (X;18) and SYT-SSX2 fusion gene.

Malignant spindle cell neoplasms are often a diagnostic challenge in histopathology, especially those arising from unusual locations. The authors report a primary synovial sarcoma of the kidney in a 19-year-old female. Initially, the tumor was considered adult Wilms' tumor exhibiting predominantly blastemal component. It was then revised to monophasic synovial sarcoma due to discovery of the characteristic chromosomal translocation (X;18)(p11.2;q11.2). This is the tenth reported case of renal synovial sarcoma with genetic confirmation. In addition to emphasizing the usefulness of genetic study in diagnostic pathology, the clinical implication of SYT/SSX subtypes and other additional chromosomal changes were also discussed by reviewing literature.