This neoplasm is not reportable.


Transient abnormal myelopoiesis

ICD-O-3 Morphology

9898/1: Transient abnormal myelopiesis
Effective 2001 and later

Not Reportable

This neoplasm is not reportable

Primary Site(s)


Alternate Names

Transient myeloproliferative disorder


Transient abnormal myelopoiesis (TAM) is a unique disorder of Down syndrome newborns that presents with clinical and morphologic findings indistinguishable from AML. The blasts have morphologic and immunologic features of megakaryocytic lineage. This is part of the myeloid proliferations with Down syndrome WHO group, which also includes myeloid leukemia associated with Down syndrome (see 9898/3).

Definitive Diagnostic Methods

This data item does not apply

Genetics Data

This data item does not apply


This data item does not apply


No treatments found

Corresponding ICD-9 Codes

238.79 Other lymphatic and hematopoietic tissues

Corresponding ICD-10 Codes

D46.7 Other myelodysplastic syndromes

Corresponding ICD-10-CM Codes (U.S. only)

D46.Z Other myelodysplastic syndrome (effective October 01, 2015)