- Renal cell carcinoma classical triad (flank pain + hematuria + palpable renal mass) is not always present in every person with RCC. Proteinuria is uncommon for RCC and other causes should be sought.
- Podocyte injury commonly leads to proteinuria and is a hallmark of minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS) and membranous nephropathy.
– Podocytes (or visceral epithelial cells) are cells in the Bowman’s capsule. The foot processes wrapping the capillaries of the glomerulus form the filtration slits
– MCD: foot processes fusion (causing larger slits)
– FSGS: focal and segmental sclerosis of the glomeruli + loss of foot processes
– Membranous: subepithelial deposits of immune complex that causes sclerosis of BM and loss of foot processes
Difference between MCD, FSGS and membranous nephropathy
- FSGS is common in Black and Hispanic people.
- Membranous nephropathy is more common in white people.
The rule of thumb is often in adults, immunosuppression with steroids ONLY is often inadequate. They often need other drugs eg cyclophosphamide.
Reference: D. Bora Hazar et al. A 72-Year-Old Woman with Proteinuria and a Kidney Mass. N Engl J Med 2015;373:1958-67