Aberrant expression of secreted proteinases and their specific inhibitors is believed to represent an important factor in the pathogenesis of invasion and metastases of malignant neoplasms. Our previous data indicated a link between elevated expression of tissue inhibitor of metalloproteinases-1 (TIMP-1) and the clinical aggressiveness of malignant non-Hodgkin's lymphomas. Further studies are presented on eighteen cases of high grade, large cell immunoblastic lymphoma in which expression at the RNA level of TIMP-1 and the metalloproteinase, 92 kDa gelatinase, were analyzed. Factors that may influence production of 92 kDa gelatinase, such as necrosis, vascularity, proliferative activity, and extranodal extension, as well as clinical parameters, such as age and sex, stage, location, and survival were assessed. Statistical analysis showed that, although clinical stage was the most important predictor of survival, after controlling for age at diagnosis, levels of 92 kDa gelatinase transcripts added to the ability to predict survival.