Abstract
Lung cancer is one of the most common malignancies in both male and female patients. It is classified into small cell lung cancers and non-small cell lung cancers. Lung adenocarcinoma is a subtype of non-small cell lung cancer and accounts for the highest prevalence of lung cancer. Eosinophils are white blood cells (WBCs) that originate from the granulocytic lineage. Hypereosinophilia is a rare condition characterized by an absolute eosinophil count (AEC) of more than 1500 cells/µL. This is different from eosinophilia, which is defined as an absolute eosinophil count of more than 500 cells/µL. Hypereosinophilia is associated with several conditions, including allergic disorders, helminth infections, rheumatologic disorders, and hematologic malignancies. Paraneoplastic eosinophilia is a rare finding in solid malignancies. Herein, we report the case of a 55-year-old male who presented with shortness of breath and chest pain and whose workup showed metastatic lung adenocarcinoma associated with hypereosinophilia in the absence of a primary bone marrow disorder.