SMARCA4 and rhabdoid tumor of the kidney: Originally recognized as a distinct entity following cytogenetic identification of monosomy 22 in renal Rhabdoid Tumors, AT/RT now encompasses CNS tumors characterized by SMARCB1 (INI-1) or SMARCA4 (BRG-1) alterations within the SWI/SNF chromatin-remodeling complex.