55 year old man with known history of lung carcinoma 2 years ago. The tumour was operated and he underwent a complete course of chemotherapy.
Recently, he developed chest pain and frank haematuria. PETCT was done for evaluation.
Scan showed two hypodense mass in mid and upper pole of left kidney, measuring 1.2cm and 2.6cm in size. The left renal mass demonstrated intense FDG uptake (SUV max 8.8 and 9.6).
A left paraaortic node measuring 1.2cm, associated with moderate FDG uptake noted is also seen.
Clinically recognised metastases to the kidney from lung carcinoma are rare despite the fact that renal metastases from lung primaries are frequent at post mortem examination. Most patients have metastatic tumor in the other locations besides the kidney. The most common tumours which metastatise to kidney are lymphoma, leukemia, and lungs. Distinction from renal cell carcinoma is difficult to differentiate and a tissue diagnosis is imperative.