Acinar Cell CA : Molecular Genetics

Comments:
Molecular Genetics of Acinar Cell CA of Pancreas: Acinar cell carcinomas show a mutation signature associated with tobacco use and defective DNA repair. There is chromosomal instability with high degree of allelic losses and gains. A subset of ACC and large percentage of mixed acinar-neuroendocrine carcinomas show alterations in MYC (gene amplification, chromosome 8 polysomy). 18q del with loss of protein DCC is considered to be an early event.

KRAS, SMAD4, and TP53 mutations are rare (unlike pancreatic ductal adenocarcinomas). CDKN2A or CDKN2B mutations have been found in a small percentage of cases. Alterations in the APC/β-catenin pathway, including mutations of APC and CTNNB1 are seen in about 10% of cases. TP53 mutations occur 12-24% of cases. Rearrangements involving BRAF and RAF1 are seen in 23% of cases. MSI is seen in 8-14% of acinar cell carcinomas in the context of Lynch syndrome.

About this image: Acinar cell carcinoma with solid sheet-like areas. Not the large vesicular nuclei and prominent nucleoli.