Acute leukemias are the most common pediatric malignancy.

Acute lymphoblastic leukemia (ALL) is the most common leukemia followed by acute myeloblastic leukemia (AML).

Annually, approximately 3,500 new cases of leukemia are diagnosed in the United States in children <20-years-old.

Peak incidence at 2–3-years-old for ALL and <2-years-old for followed by a decreasing incidence until 10-years-old when the incidence climbs with increasing age.

There is an increased incidence in children with congenital syndromes. The most common are: Downs syndrome, neurofibromatosis, Shwachman-Diamond syndrome, Bloom syndrome, ataxia telangiectasia.

Children present with constitutional symptoms of fevers weight loss, night sweats, chills and mix of signs and symptoms related the bone marrow failure and tumor burden. Thrombocytopenia presents with petechiae, mucosal bleeding, easy bruising, and less commonly as a life threatening bleed. Anemia can lead to pallor, hypersomnia, fatigue, irritability and poor feeding in infants, tachycardia with varying degrees of cardiovascular compromise. Life threatening infections related to the neutropenia.

The leukemia cell infiltration resulting in adenopathy, hepatosplenomegaly, and bone pain.

Urgent complications encountered at diagnosis related to the tumor burden need to be anticipated.