A Rare Case of Sporadic Medullary Cystic Kidney Disease with Rapidly Progressive Renal Dysfunction and Renal Enlargement Complicated by Idiopathic Nodular Glomerulosclerosis.

An 81-year-old man with hypertension and a history of smoking presented with renal enlargement and progressive renal dysfunction despite no family history of kidney disease. A renal biopsy revealed diffuse tubular, dilated, and atrophic distal tubules with cystic formation and thin irregularities in the tubular basement membrane. Although no known genetic abnormalities were detected, the patient was diagnosed with medullary cystic kidney disease (MCKD). In addition, idiopathic nodular glomerulosclerosis, which is characterized by significant mesangial expansion and accentuated glomerular nodularity and is associated with hypertension and cigarette smoking, was identified as a complication of MCKD. We herein report a rare case of sporadic MCKD with idiopathic nodular glomerulosclerosis.