Hyperthermic effects on the human metastatic liver: a TEM study.

Using ultrastructural analysis, we studied the effects of hyperthermic treatment of one case of human liver metastasis from colon carcinoma. The results indicate that the main hyperthermic response involves the neoplastic and the histiocytic cell population. The drastic decrease in metastatic cells was accompanied by the appearance of cell fragments and apoptotic bodies. Consequently, the histiocytic component (Kupffer cells) showed increased frequency, indicating an activated state. The data are consistent with a direct action of the heat on tumor cells with subsequent activation of Kupffer cells.