45 Copyright © 2019 by the Academy of Sciences and Arts of Bosnia and Herzegovina. Laboratory Work-Up of Chronic B-Cell Lymphoid Malignancies – A Value-Based Approach Min Shi, Linda Dao, Dragan Jevremovic Narrative Review Acta Medica Academica 2019;48(1):45-56 DOI: 10.5644/ama2006-124.241 Introduction Malignant lymphomas are neoplasms of ma- ture lymphocytes, involving lymph nodes as well other hematopoietic (bone marrow, spleen) and non-hematopoietic tissues (gas- trointestinal tract, skin, etc.). In the United States, lymphomas account for approxi- mately 4-5% of all new cases of malignant diseases. About 90% of all lymphomas are of B-cell lineage. Te new WHO classifcation of lymphoid malignancies continued in the steps of pre- vious versions by keeping the multifactorial approach in disease defnition (1). Clinical features are represented by aggressiveness in presentation and localization. Morphologic fndings include cell size and shape, pres- ence and distribution of nucleoli, quality and quantity of cytoplasm, and the pattern of growth. Immunophenotype of the cells is critical in assigning lineage and diferentia- tion pattern, linking the malignant cells to their normal counterparts. Cytogenetic fnd- ings are sometimes used as disease-defning events, in cases of the recurrent transloca- tions (involving MYC, CYCLIN D1, or BCL2 loci, for example), in the right clinical and morphologic context. Finally, detection of molecular abnormalities includes clonality assays for immunoglobulin or T-cell recep- tor gene rearrangements, and a plethora of novel point mutations. Te newly described mutations are most commonly discussed as prognostic variables, with very few of them approaching the level of disease-defning events (MYD88 L265P for lymphoplasma- Department of Laboratory Medicine and Pathology, Mayo Clinic Rochester MN Correspondence: jevremovic.dragan@mayo.edu Tel.: + 1 507 293 0295 Fax.: + 1 507 284 5115 Received: 26 September 2018 Accepted: 3 January 2019 Key Words: Lymphoma  Pathology  Prognosis. Te aim of study was to summarize recent developments in laboratory work-up of lymphomas and discuss their clinical relevance. Diagnosis of lymphoma requires tissue biopsy with adequate work-up by pathol- ogists. Recent developments in laboratory testing have raised the bar for establishing the diagnosis: more and more testing seems to be re- quired, while the lines between research and clinical practice are being blurred. Academic medical practice is designed to push boundaries and test new hypotheses, which eventually result in improved patient care. Ability to (relatively) cheaply screen for multiple genomic abnor- malities using new technologies is luring. Ofen, however, no change in patient management is pursued based on these results. It is there- fore useful to review which testing is truly necessary from the patient’s point of view. Conclusions. Te laboratory work-up of lymphomas in a regular clinical practice requires relatively few tests. Many new tests have prognostic value, but do not necessarily contribute to the patient management. Clinical Science