42 year old doctor, body building fanatic, with history of mild hypertension, intermittent heavy NSAID use while playing college rugby, found to have elevated Cr to 1.4 to 1.7 since 2003. Nonproteinuric. Environmental exposures neg, denies drug or anabolic steroid use. Medications – lisinopril 5 mg/d. BP 134/84 mmHg, HR 66. Rest of the examination normal. Patient is very keen to know the cause of his renal insufficiency. Would you perform the biopsy? What would it likely show?