Foci of eosinophil-related necrosis in the liver: imaging findings and correlation with eosinophilia

Abstract

Objective: The purpose of our study was to describe CT and sonographic findings of foci of eosinophil-related hepatic necrosis and to correlate those findings with eosinophil counts in the peripheral blood.

Materials and methods: We retrospectively reviewed 17 helical CT and 16 sonographic examinations (including follow-up examinations) in 10 patients with pathologically proven foci of eosinophil-related necrosis. Underlying causes were anisakiasis (n = 2), malignant neoplasms (n = 3), hypereosinophilic syndrome (n = 3), and idiopathic (n = 2). CT and sonographic images were reviewed by consensus by three radiologists, with an emphasis on the morphology and distribution of foci. Imaging findings were correlated with eosinophil counts in the peripheral blood.

Results: All foci of eosinophil-related necrosis were observed as focal hypoattenuating lesions on all phases of helical CT and as focal hypoechoic lesions on sonography. Foci varied in size and were round or oval. The number of these foci seemed to be in proportion to the percentage of eosinophils in the peripheral blood. Most foci showed interval regression on follow-up CT or sonography as peripheral blood eosinophil counts decreased.

Conclusion: Foci of eosinophil-related necrosis cause focal hepatic lesions of varying size, shape, and number on helical CT and sonography. The number and extent of these foci were closely correlated to eosinophil counts in the peripheral blood.