To elucidate the genetic mechanisms of recurrence and metastasis in
clear cell sarcoma of the kidney (CCSK), a dismal pediatric renal
cancer, we performed targeted-capture sequencing by pediatric solid
tumors panel (381 genes) for multi-sampled tumors including autopsy
samples of metastasis extracted from a single case that underwent four
relapses. Internal tandem duplication of BCOR (BCOR-ITD) was the only
truncal mutation, indicating a strong association with tumorigenesis.
Acquisition of additional mutations along tumor relapses and detection
of metastasis-specific mutations were reminiscent of the tumor
progression and therapeutic resistance of this case, leading to clonal
selection and a dismal fate.