Extensive necrosis in malignant lymphoma with granulomatous reaction mimicking tuberculosis.

Epithelioid cell granulomas occur in association with a wide range of neoplasms but necrotizing granulomas mimicking tuberculosis are less well recognized. Two cases of high-grade malignant lymphoma of Burkitt type are presented which were associated with such a response. In both cases this caused difficulty in interpretation and in one led to delayed diagnosis. Regional lymph nodes were not involved by lymphoma but contained epithelioid cell granulomas in both cases. Features that suggested that the granulomatous reaction was related to the tumour included a close spatial relation, the reticulin pattern in the areas of necrosis and the immunohistochemical demonstration of lymphoid antigens in the necrotic debris. A diligent search for mycobacteria and other micro-organisms failed to reveal any infective cause. We suggest that the local granulomatous response is a reaction to the presence of necrotic and poorly viable tumour and the granulomas in nearby lymph nodes may be a response to tumour derived debris.