Eosinophilia as the presenting sign in pancreatic cancer: an extremely rare occurrence

A case of pancreatic adenocarcinoma diagnosed following work up for eosinophilia is reported. A 68-year-old female was referred to our Hematology clinic for an absolute eosinophil count of 1869 per microliter. No allergic signs or symptoms were reported. Laboratory studies for parasitic infestations autoimmune disease and collagen vascular disease were negative. Computed tomography of the abdomen revealed a mass in the neck of the pancreas with fine needle aspiration biopsy consistent with adenocarcinoma. The patient received one cycle of modified FOLFIRINOX with complete resolution of the eosinophilia. There are rare case reports of tumor-associated blood eosinophilia in solid malignancies. The finding may be indicative of rapid disease progression and poor prognosis. Our case is the third in published English literature with eosinophilia being the initial finding in pancreatic cancer.