[Case report on the patient who showed a primary lung carcinoma accompanied with lung metastasis from renal cell carcinoma simultaneously during the clinical follow-up].

BACKGROUND: We have studied on the patient who showed a primary lung carcinoma and microscopic metastasis from renal cell carcinoma simultaneously after nephrectomy for renal cell carcinoma. PATIENT: A 57-year-old man who had an incidentally discovered right renal cell carcinoma at the time of the examination of different disease, and received nephrectomy. Two years and four months after nephrectomy, a solitary primary lung carcinoma was found. Therefore, he received lobectomy. Histopathological examination revealed that the lung tumour was a poorly differentiated adenocarcinoma, and peripheral lesions of the lung tumour, it was also discovered small clear-cell carcinoma simultaneously. At that time, we could not diagnose this carcinoma as a metastatic renal cell carcinoma. Nine months after lobectomy, new coin lesions were appeared in the lung. Therefore, we diagnosed a minimum clear lesion which was found nine months ago was metastatic renal cell carcinoma clinically. At present, the patient receives interferon-alpha therapy. RESULTS: As a result, we diagnosed primary lung carcinoma and small metastatic renal cell carcinoma simultaneously. However, the latter diagnosis could be obtained through the progression of the disease. CONCLUSION: We conclude that we must give heed to the patients with new cancerous lesions histologically when the patients treated of cancer previously.