Renal oncocytoma in a female patient with rheumatoid arthritis and secondary Sjögren’s syndrome: Non-coincidental link to autoimmunity?*

Abstract

The objective of the article was to describe a female patient with rheumatoid arthritis (RA) and secondary Sjogren’s syndrome (SS) who developed a renal oncocytoma and was cured by percutaneous cryoablation therapy. A 72-year-old female patient with a long-term history of polyarthritis involving her hands, shoulders, knees, and ankles associated with morning stiffness and rheumatoid factor of 107 U/mL (nr: <29 U/mL) and anti-CCP of 121 U/mL (nr:<5 U/mL). A diagnosis of RA was determined 10 years ago, and prednisone with methotrexate were initiated, later changed for leflunomide 20mg/day. In 2014 a diagnosis of secondary SS was determined. In April 2014, during a routine abdominal ultrasound, a tumor was found in her left kidney. A magnetic resonance imaging confirmed a solid nodule with hypervascularization on the left kidney. She was submitted to a percutaneous cryoablation procedure without any intercurrence, and it had success. The histopathological analysis demonstrated a renal oncocytoma limited to the left kidney. No chemotherapy or radiotherapy was needed. After surgery, a flare of RA was noted and was resistant to methotrexate and sulfasalazine. Rituximab was then started, and she had an excellent progressive response. Minor thyroid changes were registered by ultrasound monitoring and signs of hyperparathyroidism manifested. This observation illustrates the first ever described case of a patient with RA and secondary SS who developed several years after the RA onset, a renal oncocytoma, and was successfully treated with cryoablation therapy. The possible links between oncocytic cell metaplasia/neoplasia and autoimmunity are discussed.