Here’s how readers responded to a You Make the Call question about a patient with a morphologic presentation suggestive of acute promyelocytic leukemia (APL), but with a negative PML/RARA fusion transcript result.
Disclaimer: ASH does not recommend or endorse any specific tests, physicians, products, procedures, or opinions, and disclaims any representation, warranty, or guaranty as to the same. Reliance on any information provided in this article is solely at your own risk.
In the described case of probable PML, I would prefer adding an anthracycline (e.g., daunorubicin 60 mg/m for 3 consecutive days) to ATRA plus ATO. Low promyelocyte count in BM does not influence detection of PML/RARA transcript RNA. If no rearrangement of RARA is detected, I would add anthracycline as in regular acute myeloid leukemia.
Alexey Maschan, MD
Unlikely to be APL.
Evan D. Slater, MD
The possibility of PML is present so I would recommend flowcytometry and polymerase chain reaction (PCR) for PML/RARA detection, as there are sporadic cases with negative FISH results and positive PCR results. Some possible variants of PML include t(11,17) and t(5,17). If the diagnosis is confirmed, I would start ATO plus ATRA with hydroxyurea and adjust dose according to white blood cell count. Supportive therapy indicating low promyelocyte count does not influence detection of the PML/RARA gene.
Bassam Francis Matti, MD