Using liver allografts with warm or cold ischemia, we evaluated functional and morphological alterations in hepatocytes, sinusoidal endothelial cells and Kupffer cells in a rat transplantation model. All recipients of allografts with either 4 hr of cold or 30 min of warm ischemia lived more than 22 days and were judged viable. On the other hand, all recipients of grafts with 6 hr of cold or 60 min of warm ischemia died within 2 days and were therefore judged to be nonviable. With these viable and nonviable allograft models, hepatocyte function was evaluated by the bile output and serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase and serum lactate dehydrogenase levels; endothelial cell function was judged by the serum hyaluronic acid level, and Kupffer cell function was measured by an intravenous colloidal carbon clearance test. Hepatocyte injury was the prominent feature in warm ischemic grafts, especially in the nonviable ones. On the other hand, serum hyaluronic acid values were significantly higher in the nonviable cold ischemic group, compared with the viable counterpart, suggesting that the functional depression of endothelial cells was predominant in cold, nonviable livers. Histological examinations coincided with the above findings. The phagocytic activity of Kupffer cells was depressed by warm or cold ischemia, whereas the number of Kupffer cells was reduced in the warm ischemia group. We conclude that in liver allografts the main site of injury in warm ischemia is the hepatocytes and suggest that cold ischemia is associated with endothelial cell damage.

Among 579 autopsy cases of hepatocellular carcinoma (HCC), 55 cases (9.4%) exhibited a sarcomatous appearance. The incidence of HCC with a sarcomatous appearance has been increasing over the past 17 years. A sarcomatous appearance was found in 20 out of 335 autopsy cases of HCC (5.9%) during the 12 years from 1969 to 1980, and in 35 out of 244 autopsy cases of HCC (14.3%) during the last 6 years, when effective anticancer therapies, such as the one-shot injection of anticancer agents into the hepatic artery (one-shot therapy) and transcatheter arterial embolization (TAE), have become popular. A sarcomatous appearance was found in 20.9% of the cases undergoing anticancer therapy and in 4.2% of the cases not undergoing anticancer therapy. Among the various anticancer therapies, the sarcomatous appearance was most frequent (27.6%) in cases with repeated TAE. Thus, a close relationship between the sarcomatous appearance in HCC and anticancer therapies was suggested. Regarding the development of the sarcomatous appearance, we presume that it may be caused by the phenotypic change of HCC cells caused by anticancer therapy, or that a number of factors, including anticancer therapy, may accelerate the proliferation of the sarcomatous cells existing in the original tumor as one of the histological components. In order to clarify the true nature of sarcomatous lesions in HCC, further histological and biological studies are required.

Light microscopic, immunohistochemical and ultrastructural analysis of protocol before transplantation and after reperfusion biopsy specimens from 87 randomly selected patients was performed to assess the contribution of preservation and immunological injury to early graft failure. Most biopsy specimens were essentially normal by light microscopy before transplantation, and no particular feature could be relied on to predict function after transplantation. Ultrastructural examination of biopsy specimens before transplantation demonstrated preferential degeneration of sinusoidal lining cells, but no strict correlation was seen between ultrastructural sinusoidal integrity before transplantation and function after transplantation. The presence of zonal or severe focal necrosis and a severe neutrophilic exudate in biopsy specimens after reperfusion presaged a poor early postoperative course in most, but not all, patients. The presence of preformed lymphocytotoxic antibodies had no effect on the early clinical course, but was associated with Kupffer cell hypertrophy in needle biopsy specimens taken after transplantation. No definite evidence was seen of hyperacute rejection as a result of preformed lymphocytotoxic antibodies as detected in conventional assays. These findings suggest that preservation injury accounts for only a subset of grafts that fail to function after transplantation. Other perioperative or "recipient" factors may be of equal or greater importance in early graft dysfunction or failure.

Among 355 autopsy cases of hepatocellular carcinoma (HCC), 14 cases exhibited sarcomatous appearance (incidence, 3.9%). A clinicopathologic study was performed in these 14 cases, and the immunohistochemical localization of keratin (KRT), vimentin (VMT), albumin (ALB), fibrinogen (FBG) and alpha-fetoprotein (AFP) was also examined using the avidin-biotin complex method. Clinically, the HCCs with sarcomatous appearance were characterized by negative or low serum AFP levels and high incidence of extrahepatic metastasis. Grossly they were of infiltrative, mixed expansive and infiltrative, and pedunculated types. Histologically, the tumor consisted mainly of spindle-shaped cells and partly of multinucleated cells, and showed a sinusoidal growth pattern at the tumor-nontumor boundary. Immunohistochemically, tumor cells in the regions showing sarcomatous appearance were frequently found to be positive to KRT and VMT, whereas the percentage of positivity to ALB, FBG, and AFP were not significantly different from those in ordinary HCC. These results strongly suggest that the lesion showing sarcomatous appearance represents the sarcomatous change of HCC rather than being regarded as the complication of HCC and sarcoma.