What happened, in summary

This 53-year-old Chinese woman first developed cough and bloody sputum. One month later, enhanced chest CT showed a 5 cm peripheral mass in the left upper lung. Whole-body CT did not show distant metastasis in the brain, liver, or kidneys. She underwent left upper lobectomy with chest lymph node exploration. Pathology showed moderately differentiated squamous cell carcinoma of the lung. The tumor was classified as pT2N2M0 because cancer was found in 1 fifth-station lymph node and 2 hilar lymph nodes. Immunohistochemistry supported squamous lung cancer, with positivity for PCK, CK5/6, 34βE12, P63, and CK17, and negativity for CK19, TTF-1, CK7, and CK20; Ki-67 was greater than 10%. After surgery, she received 4 cycles of adjuvant chemotherapy with cisplatin and vinblastine. Because mediastinal lymph node dissection was incomplete and the cancer had pathologic N2 disease, she then received mediastinal radiotherapy to a total dose of 50 Gy, delivered as 2 Gy per day, 5 days per week for 5 weeks. She had a 10-month disease-free interval after chemotherapy and radiation. A routine urine test then showed white and red blood cells. Enhanced CT found a lesion in the left renal parenchyma and enlarged paraaortic lymph nodes, while brain MRI and liver CT showed no other distant metastasis. Biopsy of the kidney confirmed metastatic squamous cell lung carcinoma, marking progression to Stage IV disease. The relapse pattern was unusual because renal metastasis from lung squamous cell carcinoma is uncommon and was detected after urinary abnormalities rather than respiratory symptoms. The kidney biopsy was therefore central to confirming recurrence from the lung primary.