The pathology of intrarenal vascular lesions associated with the loin-pain-haematuria syndrome.

The histological appearances of the proximal and peripheral intrarenal arteries and renal cortex have been examined in 3 patients who underwent nephrectomy for intractable pain associated with the loin-pain-haematuria syndrome. Marked 'atherosclerotic' changes were noted to involve segmental, lobar, interlobar and arcuate arteries with evidence in one kidney of early microaneurysmal formation. These lesions of the more proximal intrarenal arteries were associated with occlusive lesions of the interlobular arteries, areas of cortical ischaemia and cortical infarcts consistent with the changes resulting from microemboli. The histological appearances correlated well with previously described angiographic findings.