CYTOMORPHOLOGICAL DETECTION OF MALIGNANT EFFUSIONS IN NON-HODGKIN LYMPHOMA: AN INSTITUTIONAL EXPERIENCE IN A DEVELOPING COUNTRY

Objective: Lymphomatous effusions of the body cavity may be the presenting feature or develop later as a complication of systemic disease. The detection rate of lymphoma in cytologic specimen is low, especially in the absence of clinical details and ancillary studies. The present study was carried out to identify light microscopic features that are useful in identifying lymphomas on effusion cytology. Methods: A 5-year retrospective study of all patients with fluid cytology or tissue biopsy reported as suspicious or positive for non-Hodgkin lymphoma (NHL) in a tertiary care was done. The cytology, histopathology, and immunohistochemistry slides were reviewed. Results: A total of 27 cases were included in the study. Correlation with the histopathological sections of all the positive cases revealed that the cytomorphology of the abnormal lymphoid cells was monomorphous and similar to those seen in the tissue biopsy. Mercury drop karyorrhexis when present was characteristic of lymphomatous effusions. The detection rates of large cell lymphomas are higher than low-grade counterparts. Non-lymphomatous effusions showed heterogeneous lymphoid cell population and lacked karyorrhexis. Conclusion: Lymphomas can give rise to effusions. In the absence of resources in developing countries, it is important to distinguish lymphomatous effusion from a reactive process based on morphology. Monomorphous population of the lymphoid cells and presence of mercury drop karyorrhexis are useful morphological clues in identifying a lymphomatous effusion. Further, tuberculosis is a common non-neoplastic process that can be mistaken for a low-grade NHL