The four main myeloproliferative disorders share several similarities such as a hypercellular marrow, a high white count with a left shift, and splenomegaly. But there are distinct morphologic and clinical differences too; that’s why they have been separated into four distinct entities.
Take chronic myelofibrosis for example. In this disorder, the myeloid cells proliferate like crazy early on. If you looked the blood and bone marrow at this early stage, you’d see a high white count with a left shift, and a hypercellular marrow, features common to all myeloproliferative disorders. But as the disease progresses, the marrow becomes replaced by fibrous tissue. The hematopoietic precursors have nowhere to grow, so they start setting up shop outside the marrow, in places like the liver and spleen. The spleen, in particular, becomes massive – even bigger than it does in the other chronic myeloproliferative disorders.
You can see evidence of the marrow fibrosis and splenomegaly in the blood if you look closely at the red cells. In squeezing through the tight fibrosis in the marrow, and in navigating through a markedly enlarged and cellular spleen, the red cells take on an unusual, “teardrop” shape. You can almost see how they dragged themselves through tight spaces, stretching their poor little bodies into elongated, pinched shapes. Another word for these teardrop cells is dacryocytes. While not specific for chronic myelofibrosis (they can occur in any case of marked splenomegaly or marrow replacement), if they are present in large numbers and the clinical setting is right, teardrop-shaped red cells are strongly suggestive of chronic myelofibrosis. You’d need to do a bone marrow biopsy to be sure, of course.
Tagsacute leukemia acute lymphoblastic leukemia acute myeloid leukemia acute promyelocytic leukemia Add new tag anemia b cells blood smear bone marrow brain tumors carcinoma cases chronic myelofibrosis chronic myeloid leukemia chronic myeloproliferative disorders coagulation cortisol cytochemistry cytogenetics essential thrombocythemia heart hemophilia immunology infection inflammation kaplan kidney laboratory tests lymphocyte lymphocytes lymphoma macrophages neoplasia neutrophil normal photoblog polycythemia vera red blood cells red cells sickle cell anemia skin squamous cell carcinoma stains student questions t cells
- Anton said Big thanks!
- Sannie said really enlightening..I actually picked A
- Kristine said Thanks, Joyce – yes – you are absolutely correct: the PTT tests the intrinsic pathway an...
- Simon Downes said Thank you! This was driving me crazy! Now I will never forget it!! I will share it with my buddies!
- Ana Maramadaumasu said This answers my question and i can understand better than what i learn in school,,,thank you very mu...
- Sri said Thank you for the detailed explanation.. It is so clear and creates an enthusiasm to read all the to...
- Joyce said Kristine, this is regarding your comment to Janarthan on 8/3/15 @1:10PM. You seem to have the intrin...
- madelyn said thank you!!!!! You made this seem so simple! =)
- Nisha said Perfectttttttt explanation!!!
- chis said very simple and power-packed explanation! i really appreciate that.
- Trude said Wow, thanks! I believe this also rules for other mutations in tumor suppressos genes. I have been se...
- joly said hi….tanx for coment