[Eosinophilia: from neoplastic disease to anguillulosis]

Hypereosinophilia (HE), defined as eosinophil count above 0.5 G/l in the peripheral blood. Most cases are secondary to other diseases. Etiological diagnosis remains complex especially as causes of HE vary across the population. Allergic diseases and parasitic infections are the predominant causes. However up to 10% of HE are secondary to tumors. Here, we describe a case of HE initially attributed to a breast cancer that turn out to be due to an angillulosis acquired just before the diagnosis of the tumor.