Incidental malignant lymphoma and lymphoproliferative disorders in lymph node dissection specimens during tumor removal in various organs

Abstract

© 2019 Faculty of Medicine Siriraj Hospital, Mahidol University. Objective: To find incidental malignant lymphoma and lymphoproliferative disorders (LPD) in lymph node dissection specimens during tumor removal in various organs. Methods: A review was performed separately by two pathologists in two rounds of all H&E-stained slides of lymph nodes found during the removal of solid tumors at Siriraj Hospital: the first round concentrating on the detection of any metastatic tumor cells in lymph node sinuses and the second round concentrating on any incidental lymphoma or LPD. Then, the results were compared to reach consensus. Immunohistochemical studies were performed to help confirm the diagnosis of lymphoma or LPD. Results: In total, 309 cases were reviewed. Lymph nodes were taken out during surgical tumor removal of the breast (110 cases), colon and rectum (57 cases), female genital organs (41 cases), lung (20 cases), thyroid (20 cases), oral cavity (16 cases), prostate (14 cases), and others (31 cases). Only 1 case (0.3%) was found to have follicular lymphoma, while 4 cases (1.3%) were found to have LPD, including in situ follicular neoplasia (1 case), suspected follicular lymphoma (1 case), and marginal zone hyperplasia (2 cases). An experienced pathologist was able to detect incidental lymphoma and LPD. Conclusion: Incidental lymphoma and LPD can be found in lymph node dissection specimens. Attention should thus be paid during histologic evaluation to find any incidental lymphoma or LPD for another round of lymph node screening after finishing the search for metastasis in the lymph node dissection or sentinel lymph node biopsy to avoid "inattentional blindness.