Basophilia with Blasts – A Diagnostic Dilemma

Basophilia is commonly seen in inflammatory and autoimmune conditions. Primary malignancies of basophils are rare, however basophilia is seen in few haematological malignancies. It is most commonly seen in myeloproliferative neoplasms. Presence of basophilia helps to differentiate chronic myeloid leukemia (CML) from acute myeloid leukemia (AML). The association of basophilia with AML is rare. We present a case of 68 year old male with complaints of fever and worsening of itching, pain and swelling in right lower limb and left upper limb. On physical examination he had mild hepatosplenomegaly and no lymphadenopathy. Complete blood count showed leucocytosis. Increase in blasts and basophils was noted on peripheral smear and bone marrow examination. Flow cytometry on bone marrow aspirate showed blasts to be of myeloid origin. A distinct population of mature basophils was also noted. After exclusion of all morphological mimickers, a final diagnosis of AML with basophilia was made. The presence of basophilia in AML may warrant a search for an underlying chromosomal abnormality to assess the prognosis of the patient. Only few cases of AML with basophilia have been reported so far and it remains a diagnostic challenge.