Tumor-associated hypereosinophilia: report of four cases.

: Hypereosinophilia is a rare manifestation of cancer. We reported four cases of tumor-associated hypereosinophilia. These cases presented with peripheral hypereosinophilia and disseminated metastatic malignancies. All cases were male, including two cases with cancer of unknown primary site, one with hepatocellular carcinoma, and one with a liver tumor. The age ranged from 27 to 55 years. They all had liver involvement. Two cases had bone marrow metastases. The leukocyte counts ranged from 78,600/microliters to 190,000/microliters. The percentage of eosinophils ranged from 20% to 77%. The eosinophil counts ranged from 15,720 to 126,350/microliters with a mean of 74,700/microliters. The first three cases died within 8 days after the malignancies were pathologically confirmed. We suggest that peripheral hypereosinophilia is a poor prognostic sign which is frequently associated with disseminated cancer.