title: Clinical characteristics that distinguish eosinophilic organ infiltration from metastatic nodule development in cancer patients with eosinophilia.
abstract: BACKGROUND
  When new space-occupying lesions are observed together with peripheral blood eosinophilia in patients diagnosed with cancer, the possibility of eosinophilic organ involvement should be differentiated from metastasis of primary cancer, since a misdiagnosis could lead to unnecessary chemotherapy. The aim of this study is to identify the clinical characteristics of eosinophilic organ involvement that distinguish it from distant metastasis in patients with primary cancer.
  
  
  METHODS
  The medical records of 43 cancer patients who developed hepatic or pulmonary nodules with peripheral blood eosinophilia between January 2005 and February 2010 in the Asan Medical Center (Seoul) were reviewed. Eosinophilic infiltration and distant metastasis were identified on the basis of pathological findings and radiological features. Fisher's exact test, χ² test or Mann-Whitney test were used for statistical analysis.
  
  
  RESULTS
  In total, 33 patients (76%) were diagnosed with eosinophilic infiltration, 5 (12%) with cancer metastasis and 5 (12%) had undetermined diagnoses. Compared to the patients with metastases, the patients with eosinophilic infiltration were significantly more likely to have serology indicating a parasitic infection, a history of eating raw food, high serum levels of total IgE, normal liver function, normal C-reactive protein levels, a normal erythrocyte sedimentation rate, and fewer and smaller nodules. The most common underlying malignancy in the eosinophilic organ infiltration group was stomach cancer. Physicians tended to neglect the eosinophilia in patients with a history of cancer.
  
  
  CONCLUSIONS
  Several clinical characteristics of eosinophilic organ infiltration distinguish it from cancer metastasis. Physicians should make greater efforts to determine the causes of organ involvement with peripheral blood eosinophilia, especially in cancer patients.
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2dong Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Taehoon
authors.initials: T
authors.lastname: Lee
authors.forename: Yoon Su
authors.initials: YS
authors.lastname: Lee
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Yoon
authors.forename: Su-Jeong
authors.initials: SJ
authors.lastname: Kim
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Bae
authors.forename: Hyouk-Soo
authors.initials: HS
authors.lastname: Kwon
authors.forename: You Sook
authors.initials: YS
authors.lastname: Cho
authors.forename: Hee-Bom
authors.initials: HB
authors.lastname: Moon
authors.forename: Tae-Bum
authors.initials: TB
authors.lastname: Kim
mesh_terms: D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D004802:Eosinophilia / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary*; D008175:Lung Neoplasms / Q000378:metabolism / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis
chemical_list: D002097:C-Reactive Protein