SARCOID-LIKE REACTION IN PATIENTS WITH MALIGNANCY

PURPOSE: To determine the radiologic features, pathogenesis, and progn ostic importance of sarcoidlike reaction in patients with malignancy. MATERIALS AND METHODS: Radiographs and computed tomographic (CT) scans of the chests of 10 patients with known malignancy and either concurr ent or subsequent development of noncaseating granulomas (NCG) were re viewed and correlated with histopathologic reports and pertinent clini cal data. RESULTS: Ten patients with malignancy were found to have eit her mediastinal or hilar lymph node enlargement (n = 4) or parenchymal lung disease (n = 6). The presumptive diagnosis was metastatic diseas e. In eight of 10 histopathologic specimens, no tumor was found, but i nnumerable NCGs were present. They were thought to be consistent with sarcoidlike reaction. In the other two specimens, only a small focus o f tumor cells was found amidst innumerable NCGs. On CT scans of the ch ests, parenchymal lung disease took the form of either ground-glass at tenuation (n = 1) or nodules following perivascular and peribronchial distributions (n = 5). CONCLUSION: Lymph node enlargement and parenchy mal lung nodules may not indicate metastatic disease. Sampling of all abnormal areas may be helpful in staging the disease and in treating a nd determining the prognosis of patients. Likewise, the discovery of N CG does not necessarily indicate sarcoidosis and may represent sarcoid like reaction.