Expression of lymphoid-associated antigens in mast cells: report of a case of systemic mast cell disease.

In this study the expression of 'classically' considered lymphoid-associated antigens (CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD19, CD20, and CD22) was explored both in peripheral blood (PB) and bone marrow (BM) mast cells (MC) in a case of systemic mast cell disease (SMCD) by means of using multiple stainings and a direct immunofluorescence technique. CD2 and CD22 were expressed in both PB and BM MC, all the remaining lymphoid-associated markers were negative. Our results suggest that the reactivity for both CD2 and CD22 in PB and BM MC would be aberrant.