Diffuse histiocytic lymphoma: the 20-year experience of an Australian teaching hospital

There is a paucity of information regarding the natural history and treatment outcome of diffuse histiocytic lymphoma (DHL) in Australia. Case records from 80 patients treated for DHL at the Royal Adelaide Hospital between 1965 and 1985 were reviewed to determine treatment outcome and prognostic information. Pathological review of biopsy specimens confirmed the correct diagnosis in 78 patients. The Ann Arbor staging criteria were unsatisfactory for prognostic purposes. We identified three prognostic groups: Localised disease (82% five-year survival), Advanced disease marrow negative (36% five-year survival), and Advanced disease marrow positive (11% five-year survival). An elevated plasma lactate dehydrogenase (LDH) and calcium (Ca++) predicted a poorer outcome; no patient with a LDH greater than 500 IU achieved longterm survival (p less than 0.001). Survival was identical for patients reclassified histologically as intermediate grade or high grade (Working Formulation). Localised disease was associated with a good prognosis (82% five-year survival) regardless of treatment modality. The outcome of patients with advanced disease has markedly improved over the last two decades, particularly with the introduction of combination chemotherapy containing doxorubicin in 1974 (p less than 0.005). Using these regimens, complete remission was achieved in 65% of patients, with a 39% five-year survival.