Diagnosis of mantle cell lymphoma on tissue acquired by free needle aspiration in conjunction with immunocytochemistry and cytokinetic studies: Possibilities and limitations

OBJECTIVE: To investigate the cytokinetic features of mantle cell lymphoma (MCL) and determine if there are measurable differences between mantle zone (MCL-MZ) and diffuse (MCL-D) types of MCL. STUDY DESIGN: Forty-five fine needle aspirates (FNAs) from 36 patients with MCL were reviewed. Immunohistochemistry, using a panel of kappa, lambda, CD5 and CD3, was applied in all cases. Ki-67 positivity using digital image analysis was measured in 29 cases. Flow cytometric analysis was performed on 40 specimens with DNA and RNA indices, and S + G²M phase was assessed. RESULTS: The great majority of cases (42 cases, 94%) were positive for CD5. There was a predominance of lambda-positive cases (lambda:kappa 2:1). MCL-D had higher mean Ki-67 values as compared to MCL-MZ (14.4% vs. 6.5%), but the differences were not statistically significant (P=.07). The majority of cases were diploid (35, 87%). MCL-D had significantly higher mean values for RNA index (P = .005). There was no significant difference in percentage of S+G²M between MCL-MZ and MCL-D; however, the diffuse type had higher mean values as compared to the mantle zone type (5.4 vs. 3.7). CONCLUSION: Tissue obtained by FNA is adequate for a diagnosis of MCL. However, while certain proliferation and RNA markers did show a trend toward being lower in MCL-MZ, differentiation between MCL-MZ and MCL-D cannot be made based on these alone; histologic architecture is necessary.