Acute myelomonocytic leukemia (AMML) is a subtype of acute myeloid leukemia (AML) marked by differentiation toward both granulocytic and monocytic cell lines. AML is more common than acute lymphocytic leukemia (ALL) in neonates and infants, and AMML is the second most common subtype of AML seen in this population, accounting for approximately 17% of reported cases. Most cases of congenital and infant leukemia are thought to be secondary to chromosomal aberrations acquired in utero.
The presenting sign is of leukemia cutis in about half of patients, with leukemia cutis preceding other signs of leukemia by as long as 4 months. Patients with AML also show a high leukocyte count, hepatosplenomegaly, and a high likelihood for central nervous system (CNS) involvement. With leukemias that present later in infancy, signs and symptoms are often less specific and can include low-grade fever, pallor, lethargy, hepatosplenomegaly, bleeding diathesis, diarrhea, and failure to thrive. CNS involvement and male sex are independent adverse prognostic factors. The prognosis of neonatal / infant AML is generally bleak with or without chemotherapy; the overall survival is only 25% at 3 years.
Acute myelomonocytic leukemia in Child
Alerts and Notices
Synopsis
Codes
ICD10CM:
C92.50 – Acute myelomonocytic leukemia, not having achieved remission
SNOMEDCT:
110005000 – AMML - Acute myelomonocytic leukemia
C92.50 – Acute myelomonocytic leukemia, not having achieved remission
SNOMEDCT:
110005000 – AMML - Acute myelomonocytic leukemia
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
Neonatal leukemia of all types must be differentiated from other conditions causing leukemoid reactions, including certain infections, hypoxia, and hemolytic disease of the newborn.
- Congenital infections due to toxoplasmosis, rubella, cytomegalovirus infection, herpes simplex virus infection, or syphilis. These infections may show dermal erythropoiesis, leukocytosis, and circulating immature leukocytes but are differentiated from leukemia on the basis of normal bone marrow examination and immunohistochemical findings, positive serologies for specific infectious agents, as well as clinical findings such as intrauterine growth retardation, microcephaly, and hepatitis.
- Hemolytic disease of the newborn (Rh and ABO incompatibility). When severe, affected neonates show hepatosplenomegaly, dermal erythropoiesis, numerous erythroblasts on peripheral smear, and even thrombocytopenia. Demonstration of Rh or ABO incompatibility with a direct antibody test or indirect Coombs test is necessary.
- Transient myeloproliferative disorder (TMD; synonyms: transient leukemia, transient abnormal myelopoiesis, transient congenital leukemia). This condition is universally associated with Down syndrome. It is clinically and morphologically indistinguishable from leukemia, except that the disorder spontaneously remits within the first months of life. TMD is associated with significant morbidity, and as many as 30% of affected individuals will develop a subsequent leukemia, most commonly acute megakaryoblastic leukemia (AMKL).
- Neuroblastoma, stage 4-A. This condition may show hepatosplenomegaly and cutaneous nodules, but peripheral counts are typically normal, and bone marrow aspiration shows characteristic neuroblastoma cells.
- Congenital HIV
- Congenital Langerhans cell histiocytosis
- Juvenile xanthogranuloma
- Hemangiomatosis
Best Tests
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
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References
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Last Updated:01/11/2022
Acute myelomonocytic leukemia in Child