Cyclin D1 expression by histiocytes may mimic cyclin D1-positive proliferation centres of chronic lymphocytic leukaemia/small lymphocytic lymphoma

The cyclin D1-positive CLL/SLL cells in this study were mostly histiocytes. The expression of cyclin D1 by histiocytes may mimic cyclin D1+ CLL/SLL; thus, the recognition of cyclin D1 expression by non-lymphoid cells in lymphoma is important.