Immunocytochemical detection of megakaryocytes by endothelial markers: a comparative study.

By endothelial markers such as FVIII, UEA-I, CD31 and QBEND/10, the Authors have investigated the immunohistochemical pattern of bone marrow megakaryocytes in myelodysplastic (8 cases) and myeloproliferative (35 cases) disorders as well as in control biopsies (8 cases). An evident cytoplasmic positivity with FVIII and UEA-I was encountered in all normal and pathological specimens, whereas the immunolocalization of CD31 was limited to megakaryocytes present in normal bone marrow biopsies or in cases of myelofibrosis. No immunostaining with QBEND/10 was observed in any case, although the most selective staining of endothelial cells of bone marrow vessels was noted with this antibody. The usefulness to utilize endothelial markers in order to identify atypical and immature forms of megakaryocytes as well as micromegakaryocytes, especially in myelofibrosis by the aid of CD31, was also discussed.