Acute Lymphoblastic Leukemia (ALL) accounts for 15 to 20% cases of all leukemia in adults and less than 10% of this patients will have Central Nervous System (CNS) infiltration at diagnosis. CNS leukemia is defined as morphologic evidence of leukemic blasts in cerebrospinal fluid and, or cranial nerves palsies with or without significant neurologic dysfunction. The majority of studies show that the patient already has leukemic blasts at peripheral blood and bone marrow when recognized the CNS infiltration, or it appears few months after acute leukemia diagnosis. The rarity of this report is that bilateral facial nerve palsy occurs in less than 2% of all the facial palsy cases and is a very uncommon form of ALL presentation. Between those few patients, all had blasts at peripheral blood, bone marrow or mediastinal mass at the same time of the diagnosis. This clinical case describes a unique situation that the patient had been diagnosed with acute T-cell leukemia because of bilateral facial nerve palsy and without any other evidence of the disease. During a follow up of five years, the patient did not develop bone medullar leukemic infiltration.
