A 67-Year-Old Woman With Chronic Proteinuria

Abstract

67-year-old woman presented with low-grade proteinuria (1040 mg/24 h) and hypertension (170/90 mm Hg). Urinalysis showed dark yellow, nonturbid urine that was negative for leukocyte esterase. The urine had a specific gravity of 1.030, pH 6.0, no glucose, and trace ketones. Laboratory findings also revealed negativity for bilirubin, blood, and nitrite in the urine. White blood cell count was 4 to 6/mm 3 . Other aspects of the physical examination were unremarkable. The patient’s medical history was significant for low-grade proteinuria (approximately 1000 mg/24 h) of 12 years and hypertension of 4 years. She had no previous history of microscopic or macroscopic hematuria, renal stones, epistaxis or hemoptysis, flank pain, or history suggestive of a connective tissue disease. She had no significant family history. A renal biopsy was performed to identify the etiology of her long-standing proteinuria. The specimen submitted for light microscopic study consisted of a single core of renal cortical tissue with up to 8 glomeruli per section, 3 of which were globally collapsed and sclerotic. The other glomeruli had patent glomerular capillary lumina; no glomerular hypercellularity was noted. A single glomerulus revealed a segmentally sclerotic segment. The visceral epithelial cells were distended by fine intracytoplasmic vacuoles (Figure 1, arrows). The interstitium exhibited slight focal widening