Fig. 3.

Schema for two possible mechanisms of ASM development in the study patient. a The first CN-LOH of 17p occurred as an incidental event in the PGCs. Subsequently, a cell which acquired the KIT mutation and lost one copy of chromosome 4 without that mutation was selected and gave rise to a dysgerminoma. After treatment for that lesion, a residual tumor cell differentiated into a mast cell and acquired the TP53 mutation in one allele. Finally, a second CN-LOH event involving 17p led to the inactivation of the TP53 gene in both alleles and caused the ASM. b A cancer stem cell carrying the KIT mutation arose from the PGCs. One of these cancer stem cells was fated to become the lineage for the dysgerminoma, which underwent a 17p LOH. Another cancer stem cell which acquired the TP53 mutation was fated to cause the ASM. A cell of this tumor lineage underwent a 17p CN-LOH which inactivated both TP53 alleles