CD5 and plasma cell myeloma: These areas had the following phenotypes: cluster designation marker 20 (CD20) positive, B-cell lymphoma (Bcl)-2-positive, Bcl-6-, CD5-, CD3-, CD21+ (in alveolar patterns), prostate-specific antigen-negative, human melanoma black marker 45-negative, melanoma marker-negative, cytokeratin-7-negative and multiple myeloma marker 1-positive in about 30% of cells, and exhibited a high proliferation index marker (Ki-67, 80%).