Hematolymphoid Neoplasms in Serous Effusions: Morphological Spectrum, Distribution, and Role of Ancillary Techniques—A Retrospective Analysis of 75 cases

Introduction Involvement of body fluids can occur at the time of diagnosis or during the disease course of hematolymphoid neoplasms. Cytodiagnosis of malignant effusion is important in effective clinical management. Objectives (1) The aims of the study were to determine the frequency of distribution of various hematolymphoid neoplasms involving body fluids, (2) to study the morphology of hematolymphoid neoplasms in fluids, and (3) to assess the role of ancillary techniques in the diagnosis. Materials and Methods In this retrospective study, all cases of hematolymphoid neoplasms involving body fluids diagnosed from January 2016 to December 2018 were evaluated. Results During the 3-year period, there were 75 cases of hematological malignancies involving body fluids. These included 48 male patients and 27 female patients. Pleural fluid was involved in majority of cases (56 cases; 74.67%), followed by ascitic fluid (17 cases; 22.67%), and pericardial fluid (2 cases; 2.67%). High cellularity, monotonous population of cells, high nuclear-cytoplasmic (N/C) ratio, indentation/irregularity of nuclear membrane, immature chromatin/irregular clumping of chromatin, increased mitosis, and karyorrhexis were the key features which helped to differentiate between reactive and neoplastic processes. There were 35 cases of B-cell neoplasms, 33 cases of T-cell neoplasms, and seven cases of myeloid neoplasms involving body cavity fluids. T-lymphoblastic lymphoma was the most common subtype (29 cases; 38.7%), followed by diffuse large B-cell lymphoma (DLBCL) (12 cases; 16%). In 53 cases, effusion was present in the initial presentation itself. Initial diagnosis was made in effusion cytology in 25 cases (33.33% of the total), with the help of flow cytometry in 20 cases, and immunohistochemistry (IHC) in cell blocks in five cases. Conclusion Diagnosis of hematolymphoid neoplasms in body fluids based on correlation with clinical details, critical evaluation of cytology findings, and comparison with previous diagnosis along with the judicious use of ancillary techniques helps in deciding an early treatment plan.