Immunocompetence and spontaneous regression of metastatic renal cell carcinoma

Spontaneous remission of pulmonary metastases from renal cell carcinoma was correlated with a positive response to dinitrochlorobenzene (DNCB). When first seen, the patient was DNCB negative and a chest radiograph showed nodular densities in the right lung and left midlung. Six months after sensitization, the patient had a positive response to DNCB and no evidence of lung metastases. Three mo later, the patient developed brain metastases although X‐ray examination showed no pulmonary nodules. A diminished response to DNCB was noted over the next several months and chest X ray verified the return of pulmonary metastases.