Role of core needle biopsy in the diagnosis of lymphoma: looking through the keyhole

Objective The aim was to evaluate the diagnostic value of core needle biopsy (CNB) for lymphoma-suspected cases. Materials and methods A total of 186 cases of lymph nodes and extranodal CNB were received at the pathology lab of MUST University and from private practice of authors between January 2016 and December 2018 with clinical suspicion of lymphoma. CNB specimens were examined and reviewed by two pathologists using hematoxylin and eosin and immunohistochemical (IHC) staining. Clinical data and sites of CNB were recorded. Adequacy and good integrity of tissues, confident pathologic diagnosis, subtyping, staging, and therapy effects were assessed. Results Of the 186 cases examined, 85% of CNB were adequate, providing confident diagnosis utilizing hematoxylin and eosin and IHC techniques. Reactive/non-neoplastic hyperplasia was the highest diagnostic entity of 27%, followed by small B-cell lymphomas (22%), Hodgkin lymphoma 18%, large B-cell lymphoma 10%, follicular lymphoma 2%, lymphoblastic lymphoma 1.5%, T-cell lymphoma 1.5%, and other lymphomas 3%. The remaining 15% of CNB were inadequate and excisional biopsy was performed. Bone marrow and liver CNB were positive in stage IV small B-cell lymphoma. CNB for follow-up showed residual or necrotic lymphoma cells in 9.1% of cases. Conclusion CNB is a highly reliable procedure for the diagnosis, subtyping, staging, and therapy follow-up of lymphoma. Sufficient tissue cores, pathologist experience, and IHC are essential requirements for confident diagnosis.