Two cases of systemic lupus erythematosus complicated by hydronephrosis and unique small structures observed in the glomerular basement membrane.

We report two cases having a similar clinical profile of systemic lupus erythematosus (SLE) complicated by hydronephrosis that developed concurrently with a similar pathological recognition of numerous unique microspherical and microtubular structures in the glomerular basement membrane (GBM). Case 1 refers to a 29-year-old woman with SLE. An increase in the level of proteinuria had been triggered by hydronephrosis. The pathological findings of the kidney revealed "bubbling" of the GBM, microspherical and microtubular structures in the GBM, and a suspicion of podocytic infolding into the GBM. Case 2 refers to a 46-year-old woman with SLE complicated with hydronephrosis. The level of proteinuria had increased, which was followed by renal biopsy. Similar pathological findings detected in Case 1 were also recognized in Case 2. The renal disorder of the two cases exhibited pathological abnormality atypical of lupus nephritis. Histopathological abnormality similar to that detected in the two cases has rarely been reported until recently. The pathogenesis of the GBM lesions of the two cases has not yet been elucidated, but we believe that there is a possibility the persistent mild autoimmune disorder and the concurrence of an obstructive state of the urinary tract may facilitate the occurrence of the pathological abnormality, because the clinical feature of the two cases are conspicuously similar to each other.