Secondary Lymphoid Tissues ›› Lymph Node ›› Neoplastic: Non-Hodgkin Lymphoma Small Lymphocytic Lymphoma* Click Here for Full Size Additional Image 1 › Microscopic Features: Increased number of small to intermediate-sized lymphocytes diffusely involving the lymph node Scattered background pseudofollicles is also sometimes noted › Normal % blood-PB, marrow-BM, lymphoid tissue-LN: PB: N/A BM: N/A LN: N/A › May Resemble: Non-neoplastic reactive Lymph node Mantle Cell Lymphoma Follicular Lymphoma › Differential Diagnoses: Non-neoplastic reactive Lymph node {83} Follicular Lymphoma Mantle cell lymphoma Burkitt Lymphoma Diffuse Large B-cell Lymphoma › Classic Immunophenotype: CD19+ CD20dim+ CD5+ CD23+ BCL1- Monotypic kappa or lambda dim-surface light chain expression › Misc: In blood it is called Chronic Lymphocytic Leukemia (CLL) Note: As opposed to CLL which is CD5+/CD23+, Mantle cell lymphoma is typically CD5+/CD23- Also, Mantle cell is BCL1+ (CyclinD1+) while CLL/SLL are BCL1- (CyclinD1-). Hence, the t(11;14) CyclinD1-IgH translocation is absent in CLL/SLL