CRP-53
CRP-53
Clinical History
The patient is a 39 year old male. Presented with anuric acute renal failure. BUN 124, creatinine 15.1. Urinalysis shows 3+ protein, 3+ blood.
Gross Description
Received in transport media are three cores measuring 11, 6 and 10 mm in length and 2 mm in diameter. Four 1-mm pieces are submitted for EM. The 10 and 11-mm cores are bisected and equally divided for immunofluorescence and light microscopy. The 6-mm piece is entirely submitted for light microscopy.
Pathology
Case CRP-053 H&E
Case CRP-053 PASH
Case CRP-053 IHC Myoglobin
Microscopic Description
Light Microscopy
Sections contain two fragments of renal cortex and two fragments of medulla. There are thirty-nine glomeruli in the three levels. One of these is obsolete, but the remainder show minimal increase in mesangial matrix and no proliferation. The glomerular basement membranes are unremarkable with the silver stain. There are no crescents. PASH and trichrome stains show mild interstitial fibrosis and focal tubular atrophy. However, there is interstitial edema, and many tubules show severe acute degenerative changes, consisting of irregular dilatation, epithelial simplification and extensive epithelial cell necrosis. Many tubules contain amorphous debris and casts which have a brownish color. A myoglobin stain is strongly positive on the material in the tubular lumina. The positive and negative controls are adequate. A few small collections of lymphocytes are noted in the interstitium, but no tubulitis is identified. The vasculature is quite well sampled. There is severe hyaline arteriolosclerosis, but the larger vessels are unremarkable.
Immunofluorescence
There are five glomeruli in the sections. There is 1+ mesangial staining for IgM, but there is no glomerular staining for IgG, IgA, Clq, C3, albumin or light chains. There is focal staining for C3 in the tubular basement membranes, and there is 3+ staining for C3 in the arterioles.
Electron Microscopy
Three thick sections containing a total of five glomeruli are available. Ultrastructural examination of three glomeruli reveals no significant increase in mesangial matrix. The glomerular basement membranes are unremarkable, and the foot processes are generally intact. No immune complex deposits are identified. The tubular epithelium shows focal degenerative changes.