CD61 is a marker of megakaryocytes/platelets.  The antigen is glycoprotein IIIa, and any cellular proliferation with megakaryocytic differentiation may express CD61.  This marker has been found useful in bone marrow biopsies looking for identifying highlighting abnormal and micromegakaryocytes, which is found in some cases of myelodysplasia (MDS) and myeloproliferative neoplasms (MPN).  

 

Some data suggests that at least 25% of the staining megakaryocytes should be micromegakaryocytes to have specificity for MDS (normal bone marrow <10% micromegakaryocytes).  The opinion of some expert hematopathologists is that a significant proportion for MDS is >50% micromegakaryocytes.

Quitmann H, Wagner S, Fischer R. Dysmegakaryopoiesis in myelodysplastic syndromes (MDS): an immunomorphometric study of bone marrow trephine biopsy specimens. Journal of Clinical Pathology. 1991.

 

Chuang SS, Li CY. Useful Panel of Antibodies for the Classification of Acute Leukemia by lmmunohistochemical Methods in Bone Marrow Trephine Biopsy Specimens. Am J Clin Pathol. 1997.

 

Jawad MD, Go RS, Reichard KK, Shi M. Increased Multinucleated Megakaryocytes as an Isolated Finding in Bone Marrow:  A Rare Finding and Its Clinical Significance. Am J Clin Pathol. 2016;146: 561–566. doi:10.1093/ajcp/aqw144

 

FOX, S.B., LORENZEN, J., HERYET, A., JONES, M., GATTER, K.C. and MASON, D.Y. (1990), Megakaryocytes in myelodysplasia: an immunohistochemical study on bone marrow trephines. Histopathology, 17: 69–74. doi:10.1111/j.1365-2559.1990.tb00665.x

 

Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 109-113.