A Study of Focal Lymphoid Aggregates and their Further Differentiation in Bone Marrow Biopsies: An Experience at Tertiary Care Hospital

Abstract

Background: Presence of lymphoid aggregates is a significant finding and have certain impacts while diagnosis and evaluations of bone marrow trephine biopsies. These aggregates are found in various malignant as well as benign disorders such as lymphomas, infections, autoimmune disorders etc. Differentiation between the type of these lymphoid follicles remains an important mainstay during diagnosis of various disorders. Aim: To evaluate the frequency of benign disorders associated with reactive lymphoid aggregates since a large number of patients undergo these biopsies prior to formation of primary diagnosis. Methods: This study was conducted in Department of Pathology, King Edward Medical University from May to June 2013. It was a cross sectional study and enrolled 152 patients. Patients with known cases of Lymphomas were excluded from the study. Results: It was found that lymphoid aggregates were found in 11% of the patients with a M:F ratio of 1.6:1. Out of these, clonal lymphoid aggregates were found in 101 (66.4%) patients while the remaining 51(33.6%) patients had reactive lymphoid nodules. Topographic distribution showed reactive aggregates were present in intertrabecular areas whereas clonal aggregates were largely found in combined paratrabecular and intertrabecular areas. The disorders associated with reactive aggregates included Myelodysplastic syndrome, aplastic anemia, viral infections, systemic autoimmune disorders and solid organ malignancies. Conclusion: Finding a lymphoid aggregate in trephine biopsies requires rigorous assessment despite of topographic distribution. Immunohistochemistry plays an important role in establishing the clonality of aggregates specially in under-resourced countries.