Among the 9 cases that lacked TP53 mutations, ATRX mutations and oncogenic gene fusions, similar to our case, one high-grade unclassified prostatic sarcoma was described to harbor a pathogenic biallelic inactivation of ARID1A. This case was a 19-years-old male patient whose tumor showed a solid, short fascicles or patternless pattern with necrosis and increased mitosis [16]. The gene discussed is ARID1A; the disease is neoplasm.