Increased survival of patients with massive lymphadenopathy and prostate cancer: evidence of heterogeneous tumour behaviour. The survival of patients with prostate cancer and radiologically detectable lymph node enlargement has been studied prospectively over an 8-year period. Computed tomography in 108 patients presenting with symptoms, signs or biochemical results suggesting lymphatic spread revealed pelvic or abdominal node masses in 60 patients; in 29 (48%), the masses measured more than 4 cm and the maximum node diameter was 15 cm. Two-thirds of patients had advanced (T3/T4) tumour stage. Following treatment, actuarial survival in all 60 patients with nodal enlargement was 40% at 5 years. Within this group, survival in 22 patients with lymphadenopathy but negative bone scans at diagnosis was significantly better than that of 38 patients with both node and bone disease (70% vs 20% at 5 years). This improvement was related both to an apparent inability of certain tumours initially to progress and seed within bone and to a marked sensitivity of the node masses to subsequent hormonal manipulation. Primary tumour grade was proportionally similar in both groups. Unexpectedly, 6 of the 38 patients with combined disease obtained a complete remission after treatment. The reason for this heterogeneous biological behaviour remains unclear; but these observations underscore the importance of vigorous treatment in all patients with advanced lymph node disease. 