Are there Fc receptors on non-lymphoreticular tumor cells?

The distribution of Fc receptors is not restricted to lymphoid cells - indeed, they were first discovered on macrophages and subsequently on a range of other leukocytes and granulocytes. It should not come as a surprise, therefore, to discover that solid, non-lymphoid tumors are generally filled to varying degrees with cells that have Fc receptor. After all, it has been known for over a century that such tumors can become infiltrated with all kinds of lymphoreticular host cells, an observation which has been claimed by some to be good morphologicalin-vivo evidence for the body's anti-cancer immune surveillance system. What did come as a surprise, then, was the claim that a considerable proportion - perhaps the vast majority - of such Fc-receptor-positive cells were tumorous, regardless of the nature or origin of the malignant tumor. R. S. Kerbel wrote in 1974 that the importance of lymphocyte-associated receptors could be 'eclipsed in terms of biological significance by the finding that an astonishing array of non-lymphoid and non-reticuliondothelial tumors appear to possess Fc types of receptors'. How does that statement hold up today? In this review, R. S. Kerbel and J. W. Dennis attempt to answer this question and summarize the current state of affairs.