Lymphography and abdominal computed tomography in the staging of non-Hodgkin lymphoma. With an analysis of discrepancies.

Ninety-one patients with non-Hodgkin lymphoma (NHL) were subjected to computed tomography (CT) and lymphography. Both examinations agreed in 74 patients (81%) with regard to the infradiaphragmatic lymph nodes. In patients undergoing CT prior to lymphography, the concordance amounted to 75 per cent. When lymphography was the initial examination, the concordance amounted to 86 per cent. Lymphography was abnormal in 30 per cent of the patients with a normal CT scan and in 93 per cent of those with an abnormal CT scan as the first examination. CT was abnormal in 4 per cent of patients with a normal lymphogram and in 84 per cent of those with an abnormal lymphogram as the first examination. CT did not detect mesenteric or retrocrural lymph node enlargement in the absence of retroperitoneal lymph node involvement. Eleven patients had extranodal manifestations of the disease (excluding liver and spleen), and 3 were detected primarily with CT. Lymphography is the most complete examination for the infradiaphragmatic lymph nodes for staging purposes. Although CT outlined the disease better, it changed the lymphographic diagnosis in only 2 per cent of the patients. Lymphography modified the CT stage in 15 per cent of the patients. When abdominal CT is performed first, in staging patients with NHL, lymphography will only yield additional information when CT is normal or equivocal.