The bone marrow in myeloproliferative and dysmyelopoietic syndromes.

The myeloproliferative and dysmyelopoietic syndromes are complex disorders that are interrelated and not always easily diagnosed on morphologic grounds alone. In particular, in the case of the myeloproliferative diseases, the diagnostic pathologist should avoid the pitfall of attempting to make a definite diagnosis in the absence of appropriate laboratory and clinical data. The morphologic features in given myeloproliferative diseases are not always specific; and, as the disorders evolve, they may closely mimic one another. With respect to the dysmyelopoietic syndromes, care must be taken not to confuse them with megaloblastic anemias or other conditions that do not have the same ominous prognosis. Distinction between the varying syndromes may frequently also be difficult, and on occasion one may have difficulty placing them within the appropriate context. Only careful correlation with clinical laboratory findings and history will result in accurate diagnoses.