Carcinoma of the lungs causing enlarged kidneys

Bilateral enlarged kidneys can be caused by a number of conditions. Renal metastasis is included in the differential diagnosis. We report a case of a 67-year-old woman with a 6-month history of productive cough and unintentional weight loss. Cavitary pulmonary lesions and bilateral enlarged kidneys were noted on imaging studies. Hematuria, azotemia, and proteinuria were present. Renal biopsy showed squamous carcinoma cells invading normal-appearing glomeruli and atrophic tubules. The invasive squamous cells stained negative for CK7 and CK 20. Lung biopsy confirmed squamous cell carcinoma. Our case shows that in patients with renal enlargement, even with the absence of a focal mass, renal metastasis should be considered, especially in those with suspected or diagnosed malignancy elsewhere.