Introduction: Congenital leukemia is defined as leukemia that develops intra uterine. It is an extremely rare malignancy associated with poor prognosis and a poorly understood natural history. Incidence reported to be 1 per-5 million neonates. Acute myeloblastic leukemia is more common than acute lymphoblastic leukemia in neonate. Clinical signs of neonatal leukemia among various patients such as hepatosplenomegaly, enlarged lymph nodes, leukemia cutis, and hyperleukocytosis.

Case Report: We present a 6-days-old female neonate, referred to Sanglah Hospital with respiratory distress and lethargy. We found her with high breathing effort and fever. Physical examination found hepatomegaly. Laboratory examinations showed hyperleukocytosis (leucocyte count 140.000/mm3), anemia (hemoglobin 12.56 g/dL), normal thrombocytes count (245.400/mm3), and other laboratories within normal limits. Peripheral blood smear showed erythrocyte with normocytic normochromic, normoblastemia, leucocytes with elevated white blood cell count, immature white blood cells (blasts) as appeared in acute leukemia. Leukemia phenotyping showed myeloid lineage with aberrant expression CD 7 appropriate to acute myeloblastic leukemia. We diagnosed the patient with acute myeloblastic leukemia. Patient got hydration intravenously in order to prevent leukostasis syndrome. We planned a chemotherapy protocol.

Conclusion: Acute myeloblastic leukemia in neonate is a rare case. It was fetal form of malignant diseases with various clinical presentation such as high breathing effort and hyperleukocytosis. Its exact cause is still not fully understood. Congenital leukemia has a poor prognosis with an overall survival rate only 20% at 2 years of age.

Keywords: Acute myeloblastic leukemia, Hyperleukocytosis, Malignancy, Neonate