CRP-08
CRP-08
Clinical History
The patient is a 48 year old male with negative ANA, negative hepatitis B and C, negative rheumatoid factor. Increasing abdominal girth and lower extremity edema for one month. BUN 15, creatinine 0.6, creatinine clearance 90 ml/min, urinary protein 3.4 g/24 hr.
Gross Description:
Received in Zeus fixative is one core measuring 13 mm in length and 1 mm in diameter. This is entirely submitted for immunofluorescence. Received in Carson's fixative is one core measuring 7 mm in length and 1 mm in diameter. Two 1-mm pieces are taken for EM, and the remainder is submitted for light microscopy.
Pathology
Case CRP-008 H&E
Case CRP-008 PASH
Case CRP-008 Silver
Microscopic Description:
Light Microscopy:
The specimen consists of a small fragment of renal cortex that contains 17 glomeruli in the three levels. None of these are obsolete, and none show segmental sclerosis or hyalinosis. All of the glomeruli are similar and show no significant mesangial expansion or proliferation, but the capillary basement membranes are generally thickened with the silver and PASH stains. Silver stains shows definite spike formation along the epithelial surfaces. There is very mild focal interstitial fibrosis, which is accompanied by mild tubular atrophy. However, overall the tubules and interstitium are quite well preserved. There are no inflammatory infiltrates. Arterioles and small arteries show only mild focal intimal thickening.
Immunofluorescence:
There are four glomeruli in the sections, and one is obsolete. There is 2+ granular staining along the capillary basement membranes for IgG and kappa light chains; there is 1+ staining for lambda in the same distribution. There is no staining in the glomeruli for IgM, IgA, Clq or C3. There is no staining in the tubular basement membranes or vessels.
Electron Microscopy:
Two thick sections are available, but there is only one glomerulus, which is similar to those described above and shows thickened capillary basement membranes with no significant mesangial expansion or hypercellularity. Ultrastructural examination reveals moderate irregular thickening of the capillary basement membranes, and the epithelial cell foot processes are completely effaced. Widely scattered subepithelial electron dense deposits are identified. No mesangial deposits are noted.