VIMENTIN-POSITIVE GASTRIC CARCINOMAS WITH RHABDOID FEATURES - A CLINICOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY

We studied 71 patients with solid-type gastric adenocarcinoma selected from 5,437 surgically resected specimens during the period from 1975 to 1988; six had vimentin-positive adenocarcinomas, and five of these were advanced. One was at an early stage. All six tumors showed the same histologic features and had either a diffuse or alveolar arrangement, with tumor cells having either poor or no cohesiveness. Many tumor cells were round to polygonal, with eosinophilic or clear cytoplasm and large, eccentric vesicular nuclei, as seen in malignant rhabdoid tumors of the kidney. In all cases, the cytoplasm showed coexpression of vimentin and cytokeratin as revealed by double immunostaining. Four of the five cases with advanced carcinoma died of the disease 1 to 6 months after surgery. The cases with vimentin-positive tumors had significantly poorer prognoses than those with vimentin-negative tumors. We also studied adenocarcinomas of various histologic types randomly selected from our file (160 intestinal type and 69 diffuse type of Lauren) but failed to detect any vimentin positive ones. These results indicate that vimentin is expressed in some of the solid-type adenocarcinomas, which have a poor prognosis, and indicating that rhabdoid-like cells may be found in a variety of adenocarcinomas of the stomach.