Renal granuloma and mesangial proliferative glomerulonephritis in leprosy.
A 17-year-old, Yemeni male patient with borderline lepromatous leprosy and erythema nodosum leprosum (ENL) developed a nephritic range proteinuria. A renal biopsy revealed mesangial proliferative glomerulonephritis and epithelioid granulomas in the interstitium. The presence of granular immunofluorescence for C3 and electron-dense deposits in the glomeruli indicated an immune complex glomerulonephritis. Clinical signs of ENL subsided rapidly under steroid treatment. The unusual combination of proliferative glomerulonephritis and epithelioid granulomas in leprosy is presented and discussed.