Sarcoidosis manifesting as a pseudotumorous renal mass

A 53 year-old African American woman with a three-year history of pulmonary sarcoidosis had a follow-up computed tomographic scan to evaluate the status of her disease and response to treatment. On the scan, an abnormal, hypodense mass on the left renal superior pole, which was not present on previous scans, was incidentally discovered. The initial concern was of carcinoma, despite her lack of any urinary symptoms. She underwent further evaluation with magnetic resonance, and the enhancement pattern and the shape of the mass were more suggestive of lymphoma or infarction than a carcinoma. A review of literature revealed sparse case reports demonstrating sarcoidosis presenting as infiltrative granulomatous masses resembling tumors with nonspecific imaging qualities. This diagnosis was entertained and then proven by biopsy. Pseudotumorous renal sarcoid should be in the differential of renal masses, especially in patients with a history of sarcoidosis, as it alters clinical management.