Normal anatomy and limitations in CT interpretation of lymph node disease.

The CT appearance of normal retroperitoneal lymph nodes has been described. In many instances the structures are too small to be identified. other retroperitoneal structures, such as collapsed bowel loops, vessels, and other perirenal structures, may simulate the presence of nodes. CT is of great benefit in disease with bulky tumors, such as non-Hodgkin's lymphoma, testicular tumors, etc. Its usefulness is much more limited in disease that may have extensive nodal involvement but no significant enlargement of the nodes. The accuracy of CT scanning in Hodgkin's disease and in many instances of genitourinary tumors is questioned, and we submit that further studies are needed to establish the reliability of this mode of examination.