He HG, Wu CQ, Ye K, et al. - Researchers sought to differentiate atypical focal segmental lesions (aFSL) from typical focal segmental glomerulosclerosis (FSGS) in idiopathic membranous nephropathy (IMN). Further, they sought to ascertain the clinicopathological factors that are predictive of the primary outcome of IMN patients that was defined as a 50% decline in the initial estimated glomerular filtration rate or end-stage renal disease incidence. They defined an atypical focal segmental lesion as those with pure synechia, segmental hyperplasia of podocytes or thickening of the GBM in accompaniment to proliferation of the mesangial matrix, and absence of typical FSGS. From January 1, 2007, to December 31, 2017, 716 patients with biopsy-proven IMN were analyzed; of these 174 patients had FSGS, while 161 patients had aFSL. Patients without FSL and patients with aFSL showed no significant difference in outcome, although the patients with aFSL had lower levels of serum albumin and estimate glomerular filtration rate, higher level of urinary protein, more severe renal lesions with proliferation of the mesangial area, tubulointerstitial fibrosis and vascular sclerosis. For the primary outcome, FSGS, excluding atypical lesions, was an independent predictor.