Pale bodies in hepatocellular carcinoma

Histochemical, immunohistochemical and ultrastructural studies were perform ed on cases of hepatocellular carcinoma (HCC) with pale bodies (PB), HCC co ntaining PBs was observed in 3 (5.5%) of 55 consecutively resected HCC case s. Histologically, a large number of hepatocytes displayed pale or eosinoph ilic staining of the cytoplasm, resulting in ground-glass appearance. They were aggregated in nodular pattern, or diffusely intermixed with other mali gnant hepatocytes. PBs were negative for periodic-acid Schiff and Masson's trichrome staining. The inclusions showed a strong positive reaction for fi brinogen and some of them were weakly positive for albumin but negative for hepatitis B surface antigen, hepatitis B core antigen, alpha-fetoprotein a nd alpha-1-antitrypsin. Ultrastructurally, PBs were membrane-bound and cont ained granular materials of moderate electron density, and were closely rel ated to dilated rough endoplasmic reticulum. These findings support that PB s are secretory fibrinogen accumulated in cystic ER and that such intracell ular accumulation possibly reflects a defective transport of fibrinogen.