Photo #7 and #8 are Congo red stains.

Immunofluorescence microscopy shows granular deposits of high intensity of IgG in mesangia. The kappa and lambda stains are difficult to interpret.

 The fibrils measure approximately 17 nm.

 这个病例应该归入到系膜结节性硬化肾小球病这一大类，鉴别诊断包括糖尿病、淀粉样变、单克隆球蛋白沉积症、膜增生性GN，Ⅲ型胶原肾病，纤维样肾小球病，免疫触须样肾小球病等不下十种疾病，这个病例刚果红染色阴性，结合电镜，考虑为纤维样肾小球病。

 厉害，电镜咱都不知道怎么看呢。

 刚果红是阴性吗？弱阳性？

以下是引用geng72在2009-8-25 9:34:00的发言：  这个病例应该归入到系膜结节性硬化肾小球病这一大类，鉴别诊断包括糖尿病、淀粉样变、单克隆球蛋白沉积症、膜增生性GN，Ⅲ型胶原肾病，纤维样肾小球病，免疫触须样肾小球病等不下十种疾病，这个病例刚果红染色阴性，结合电镜，考虑为纤维样肾小球病。

I agree with Dr.Geng's comment. In my report, I stated that "The biopsy reveals fibrillary deposits in glomeruli with negative Congo red stain. These findings suggest the diagnosis of fibrillary glomerulonephropathy.  Since the deposits are small, Congo red stains may not be sensitive enough to demonstrate the positivity and birefringence. Therefore, renal amyloidosis should be considered as the differential diagnosis. Clinical correlation is needed. The biopsy excludes membranous glomerulonephropathy, focal segmental glomerulosclerosis and minimal change disease, etc, as causes of nephrotic syndrome."

以下是引用tata在2009-9-1 22:03:00的发言：  刚果红是阴性吗？弱阳性？

Thank you, tata for your involvement of the discussion. The above Congo red stain was interpreted as negative. I only grade Congo red stain as either positive or negative. A positive Congo red stain should be red under light microscope, but more importantly should demonstrate apple-green birefringence under polarized light. Without apple-green birefringeence, I will interpret the Congo red stain as negative.