Video
Myeloproliferative Neoplasms: Myelofibrosis
Author(s):
Dr Jamile Shammo explains the process of diagnosing myelofibrosis and highlights the importance of bone marrow biopsies.
Rami Komrokji, MD: Let’s talk about myelofibrosis [MF]. Of those diseases, this is probably the most symptomatic disease, with a high burden on patients and worse outcome in general. Jamile, can you walk us through myelofibrosis? How do we diagnose, differentiate, and approach it? How do you risk stratify those patients?
Jamile Shammo, MD, FACP, FASCP: Myelofibrosis is the MPN [myeloproliferative neoplasm] associated with the worst outcome. It’s so critical to identify it right away. The most challenging piece about myelofibrosis is getting the doctors to do a bone marrow biopsy, because the only way to make a diagnosis of myelofibrosis is by demonstrating that you have 2- or 3-plus reticulin fibrosis. That becomes more critical in patients who have prior PV [polycythemia vera] or ET [essential thrombocythemia].
Because the progression can be insidious unless you’re totally on top of it, it’s important to look at the whole leukoerythroblastic picture if you’re familiar with the diagnosis of post-ET or post-PV MF, the development of anemia, leukoerythroblastosis, new splenomegaly, etc. You look at the constitutional symptoms and whether your patient with PV isn’t requiring phlebotomy and developing anemia when they shouldn’t, then perhaps you do a bone marrow biopsy. In someone who may have thrombocytosis without an explanation, you’d need to do bone marrow biopsy to make that diagnosis.
Essentially, that’s what should be done to make this diagnosis. Then it’s important to obtain all additional genetic testing that’s included in the cytogenetics when the diagnosis is made. But there’s a problem with that, because sometimes those patients can be a dry tap and you might not be able to obtain genetic tests or genetics. I typically get them from the peripheral blood, but I’m curious to see what you do. Next-generation sequencing has become so important for risk stratification and to determine what to do in terms of stem cell transplant, which continues to be the only curative treatment for this subset of patients. Granted, assessment of symptoms is so important in this patient population. It should be done at baseline and as we move forward with various treatments we employ.
Rami Komrokji, MD: I agree. We now know more about the phenotypes of myelofibrosis: cytopenic vs proliferative. The patient presentation with myelofibrosis is either those who have cytopenia predominantly up front or proliferative with splenomegaly constitutional symptoms. I always like to point out that not every fibrosis you see in the bone marrow is myelofibrosis. That can be seen with diseases that mimic myelofibrosis, like myelodysplastic syndrome. I’ve had several cases where it was marginal zone lymphoma or hairy cell leukemia. Not every fibrosis in the bone marrow is myelofibrosis.
On the other hand, you don’t always need to see fibrosis to establish the diagnosis of myelofibrosis, because now we talk about this prefibrotic myelofibrosis entity, where the classical megakaryocytic clustering that we see in MPN is enough to make the diagnosis. They don’t have to have the +2, +3, but it’s key. A lot of those patients will have evidence of a clonal marker. Almost 90% will have either JAK2, MPL, or calreticulin. I always go extensively more than if they were triple negative to make sure we’re labeling this the right way. To your point, we do most of the next-generation sequencing on peripheral blood in those patients. The concordance is pretty good and high. As you mentioned, many times with the bone marrow, it’s a dry tap.
Transcript edited for clarity.
