A CASE OF PLEOMORPHIC CARCINOMA OF THE PANCREAS SHOWING SEQUENTIAL HISTOLOGICAL CHANGE BY IMMUNOHISTOCHEMICAL STUDY

Pleomorphic carcinoma of the pancreas is a rare, histologically charac terized pancreatic tumor with a rapid and fatal course. We report a ca se of a resected pleomorphic carcinoma located in the body of the panc reas in a 61-yr-old male. Histological analysis of the resected specim en revealed the coexistence of pleomorphic carcinoma with adenocarcino ma, but the recurrent tumors at autopsy 20 mo later were only of the a denocarcinomatous type. Cells in the adenocarcinomatous component show ed a diffuse reactivity for CA19-9, CEA, and cytokeratin, and a focal reactivity for vimentin. In contrast, vimentin was diffusely expressed in pleomorphic lesion. Adenocarcinoma at autopsy expressed CA19-9, CE A, and cytokeratin, but not vimentin. These findings suggest that the recurrent adenocarcinoma may have developed as a consequence of sequen tial change in the nature of the tumor.