RESUMO
The neonatal leukemoid reaction is an acute response of the body to stress. Any inflammatory processes in the newborn period may lead to an increase in the white blood cell (WBC) count. Hyperleukocytosis refers to an extremely elevated leukocyte count beyond 100,000/cubic millimeter (cumm). Here, we report a case of a leukemoid reaction in a newborn who presented with fever, swelling over the neck, and failure to thrive. Peripheral smear showed the presence of all precursors of white blood cells, but no blast cells were seen. Fine needle aspiration cytology (FNAC) did not show any abnormal cells or any evidence of leukemia. Hence, the diagnosis of a leukemoid reaction was made. Hyperleukocytosis presenting as palpable lymphadenopathy in a neonate is a rare finding that was seen in this case secondary to septicemia.