The role of immunohistochemistry in the diagnosis of extra nodal lymphomas

Poorly differentiated or undifferentiated malignancies are always a challenge to the pathologists in ascertaining the lineage. Varied clinical presentation, uncommon location and morphology further complicate the issue. Immunohistochemistry made a revolutionary change in the diagnosis of these cases especially when these poorly differentiated malignancies turned out to be lymphomas, as lymphomas have an overall better survival with treatment. Lymphomas at the extranodal sites are usually of non Hodgkin variety. This study done over a period of 1 year at a tertiary health care institute with the panel of immunohistochemical markers on 25 cases of poorly differentiated or undifferentiated malignancies, had identified 19 cases of extranodal lymphomas of B cell Non Hodgkin lymphoma. Non Hodgkin lymphoma occurring in rare sites like prostate and bone were reported and helped in the appropriate management of the patient.