Timely integrated molecular profiling identified maRPF secondary to metastatic pancreatic adenocarcinoma, revealing rare genomic alterations, including a truncating <i>ARID1A</i> mutation NM_006015:c.4336C>T (p. R1446*) and <i>CCND1/FGF3/FGF4/FGF19</i> (11q13) co-amplification, which resolved diagnostic ambiguity and delineated disease biology. This evidence concerns the gene ARID1A and pancreatic adenocarcinoma.