The outside marrow biopsy contains
many promyelocytes on the aspirate smear, which account for
approximately 25% of marrow cells. The trephine biopsy also shows
clusters of precursor myeloid cells. The myeloblasts are slightly
increased (4.5%). The promyelocytes reveal no atypical features
and no dysplasia is present on other lineages.
The case was diagnosed
as acute myeloid leukemia by an outside institution, and the patient
was sent to COH for treatment. Upon review of the outside sides,
we consider this as a left-shifted marrow and no evidence of AML.
The patient was closely
observed for several weeks, and another marrow biopsy at COH
demonstrates normal marrow (see below).
investigation of clinical history, the patient received G(M)-CSF
at the outside institution several days before the marrow biopsy.
marrow due to treatment or infection may closely mimic AML;
clinical history and careful examination of the aspirate smear are
crucial to reach an accurate diagnosis. Flow cytometry for
aberrant markers (if any) and cytogenetic/molecular studies for
chromosomal abnormalities (if any) are also very helpful.