American Burkitt's lymphoma: a clinicopathologic study of 30 cases. I. Clinical factors relating to prolonged survival.

The presenting clinical characteristics and the results of therapy in 30 cases of American Burkitt's lymphoma are described. Five patients presented with localized disease. The abdomen was the most frequent site of involvement (19 cases). Serum lactic dehydrogenase (LDH) levels closely correlated with extent of tumor mass. Of the 22 patients treated with large doses of parenteral cyclophosphamide, complete remission was achieved in 13 (59 per cent). Of these only four have had a relapse, all within 12 months of treatment. The remainder are alive, free of disease and have not received any treatment for up to 80 months or more. The site and volume of tumor mass predicted for prolonged survival. None of the six patients with bone marrow or central nervous system involvement remained tumor-free. A complete remission was achieved in 8 of 9 patients with presenting LDH levels of less than 700 IU/ml and they have remained free of disease, whereas only 4 of 13 patients with LDH levels greater than 700 IU/ml had a complete response and 3 of these had a relapse within 12 months. In six cases, the massive tumor regression following chemotherapy was associated with serious metabolid consequences including hyperkalemia (six cases), hypocalcemia, hyperphosphatemia (one case) and lactic acidosis (one case). There were four sudden deaths in less than 48 hours after chemotherapy; two of these were attributable to hyperkalemia. In all cases therw were large tumor masses and/or elevated serum LDH levels.