Cancer and Eosinophilia

The investigations by Slungaard and colleagues, described in this issue,¹ deal with the mechanism of a spectacular elevation of blood eosinophils in a patient with lung cancer and provide us with a satisfying, although not too surprising, explanation for this well-known phenomenon.² The manifestation always evokes puzzled discussion and usually prompts a search for some other cause of the eosinophilia, such as co-existing parasitic infestation or drug allergy. When these are not found, the question asked is whether the hematologic reaction indicates some peculiar immunologic response to the tumor or points to a special character of the neoplasm.Actually, a . . .