Chronic basophilic leukemia; A rare myeloproliferative disorder and the role of flow cytometry for its diagnosis

Chronic basophilic leukemia (CBL) is a rare disorder and according to the published data, few cases have been reported as primary CBL. Morphologic findings in CBL mostly mimic chronic eosinophilic leukemia and basophils have unusual and dysplastic morphology. A 47-year-old patient was referred to the hospital with gastrointestinal symptoms and bloating. Complete blood count (CBC) showed leukocytosis and marked eosinophilia. After evaluating the peripheral blood smear (PBS), abnormal leukocytes with hypersegmented nuclei along with an increase in eosinophils were observed. For further investigation, the patient was referred to the hematology clinic and underwent bone marrow aspiration and biopsy. After the morphological examination, flow cytometry was performed on the aspiration sample to accurately diagnose the disease. Flow cytometric findings were in favor of CBL. Since morphological findings are unreliable for basophil detection and definite diagnosis, flow cytometry is a reliable method for the precise detection of basophils, especially in CBL.