ANALGESIC NEPHROPATHY
Analgesic nephropathy is a chronic tubulointerstitial disease, it
represents an important cause of end stage renal failure.
Pathology:
The following pathologic features could be seen in analgesic
nephropathy:
- Renal Papillary Necrosis (RPN).
- Chronic Interstitial Nephritis.
- Vascular (Capillary) Sclerosis.
- Transitional Cell Carcinoma of the Urothelium.
Macroscopic appearance:
The kidney is small in size. The capsule is thick and adherent, with
prominent scars and multiple small cysts seen on the surface. Cut surface
will show the brownish-black necrotic shrunken papillae with atrophy of
the overlying cortical tissue and hypertrophy of the intervening columns of
Bertini (Figure 6.2).
Microscopic appearance:
- Renal papillary necrosis (RPN):
Is the primary feature of analgesic nephropathy, resulting from
medullary cytotoxicity and ischemic infarct. Histologically, RPN may be
divided into three stages according to the extent of necrosis, starting by
papillary tip necrosis to complete papillary necrosis. A striking feature is
absence of inflammatory infiltrate and the presence of calcification of the
involved papillae. Separation and loss of a necrotic papilla result in the
formation of a cavity which becomes lined by fibrous tissue. - Chronic interstitial nephritis: