The reliability of lymphoma diagnosis in small tissue samples is heavily influenced by lymphoma subtype.
A specific pathologic diagnosis is important in malignant lymphoma because the diverse disease subtypes require tailored approaches to clinical management. Reliance on small samples obtained with cutting needles has been advocated as a less invasive alternative to using larger, excised samples. Although published studies have demonstrated the safety and apparent sufficiency of this approach in informing clinical care, none have systematically determined the accuracy of pathologic lymphoma subtyping based on very small samples. We used a tissue microarray representing 67 cases of malignant lymphoma and 17 samples of nonneoplastic lymphoid tissue to model lymphoma diagnosis in small samples. Overall, 73.8% of the cases were diagnosed with a level of confidence deemed sufficient for directing clinical management; 85.9% of these diagnoses were accurate. Small cell lymphomas with highly distinctive immunophenotypes, including small lymphocytic, mantle cell, and T-lymphoblastic lymphoma, were recognized most consistently and accurately in the small samples. In contrast, follicular lymphoma and marginal zone lymphoma were especially difficult. Our results indicate that the reliability of lymphoma diagnoses based on small samples is heavily influenced by lymphoma subtype.
Farmer
Patricia L
PL
The Department of Pathology and Molecular Medicine, Queen's Cancer Research Institute, Queen's University, Kingston, Canada.
Bailey
Denis J
DJ
Burns
Bruce F
BF
Day
Andrew
A
LeBrun
David P
DP
D006801:Humans; D016130:Immunophenotyping; D008223:Lymphoma / Q000175:diagnosis* / Q000473:pathology; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D046888:Tissue Array Analysis / Q000379:methods*