Basaloid carcinoma of the pancreas—clinicopathological presentation and oncogenetic snapshot of a rare entity

Abstract

We report a case of basaloid pancreatic carcinoma with clinical, pathological, and genomic data. The 73-year-old male patient had jaundice, acholic stool, diarrhea, weight loss, and a large, painless gall bladder. His GGT was highly elevated. The pancreatic head contained a tumor, which was resected by partial pancreatoduodenectomy with pancreato-gastric anastomosis, cholecystectomy, and lymphadenectomy. On gross examination, a 3.8-cm white firm nodule was found, which microscopically was composed of basaloid cell nests with a less than usual desmoplastic stromal background and focally PANIN. Immunohistochemical profile displayed strong CK5/6, CK19, p63, EGFR, vimentin, and evident CK14 expression and absence of expression of CK7, chromogranin, synaptophysin, and BRCA1. A high Ki-67 index and p53 expression were noted. Sequencing of the most frequent 46 oncogenes with ionTorrent (AmpliSeq PCR) method identified PIK3CA, KRAS, and TP53 genes as drivers and variants of the FGFR3, PDGFRA, KIT, KDR, EGFR, RET, and ATM genes. The tumor we report displays histopathological appearances similar to the previously described case and a genomic landscape fitting to the general population of pancreatic carcinomas. We hypothesize that this tumor may belong to the group of DNA damage repair-deficient pancreatic carcinoma subgroup.