A tumor derived from the pancreas, for example, is treated differently from one derived from the ovary. Adenocarcinoma vs. mesothelioma. Mesotheliomas are of major legal consequence, since they often relate to exposure to asbestos, while adenocarcinomas are not usually linked to such exposure. In general, mesotheliomas require immunohistochemical confirmation before legal measures are initiated. Lymphoma vs. reactive hyperplasia.
Lymphomas are rare in the usual practice, while benign enlargement of lymph nodes is common.
Distinguishing between these two entities can be difficult. Scientific advances now make this distinction possible. Any small round-cell tumor with no evidence of differentiation using routine stains merits immunohistochemical evaluation to determine the cell of origin. Imprecise or incorrect diagnosis carries a real risk of incorrect treatment. Prostate cancer may invade the bladder, and bladder tumors may invade the prostate, but the therapies for these two entities differ markedly.