| Abstract: | Intracytoplasmic lumina, each with a peripheral halo and spikes, a hitherto undescribed histological structure, were found in several human carcinomas. Similar structures found at the free surfaces of carcinoma cells, or those composed of several individual carcinoma cells, were designated extracytoplasmic lumina with a peripheral halo and spikes. Haloes were seen along the cytoplasm around the lumina, and the spikes penetrated into the cytoplasmic haloes. Transmission electron microscopy revealed that these spicular bodies were lumina equipped with microvilli containing an actin core. Spicular bodies were found in the following neoplasms; 22% of hepatocellular carcinomas (11/50), 35% of colonic adenocarcinomas (7/20), 31% of gastric adenocarcinomas (16/51). In contrast, no or only very occasional spicular bodies were found in thyroid (0/20) and mammary (1/22) adenocarcinomas. Although the diagnostic value of this structure is unknown at the present time, its identification in a carcinoma may be a histologic indicator of its endodermal nature. Acta Pathol Jpn 40: 815-819, 1990. |
