CRP-39

CRP-39

Clinical History

The patient is a 54 year old white woman. Hematuria, BUN 11, creatinine 0.6, urinary protein 131 mg/24 hours. BP 130/70.

Gross Description

Received in transport media are two cores of renal tissue measuring 16.5 and 5.5 mm in length and 2 mm in diameter. A 1-mm fragment is taken from the 5.5 mm piece for EM, and the remaining portion is submitted for immunofluorescence. The entire 16 mm fragment is submitted for light microscopy.

Pathology

Case CRP-039 PASH

Microscopic Description, Immunofluorescence, and Electron Microscopy

Microscopic Description

Light Microscopy

The specimen consists of a large fragment of renal cortex and medulla. The middle of the specimen is medulla, and there are small portions of cortex on each end. There are approximately fifty-three glomeruli in the sections. Two are obsolete, and another shows advanced ischemic thickening and collapse. However, the remaining glomeruli are all similar and show minimal focal mesangial expansion with no significant hypercellularity. There are no segmental areas of proliferation or sclerosis. No crescents are present. The silver stain does not demonstrate any abnormalities of the basement membranes. Some of the glomeruli contain red blood cells in Bowman’s space indicating hematuria of glomerular origin. There is a definite diffuse mild increase in interstitial fibrous tissue. No inflammatory infiltrates are present. There is no significant tubular atrophy or dropout. Large vessels show mild focal intimal fibrosis but are otherwise unremarkable. The arterioles are also unremarkable.

Immunofluorescence

There are eight glomeruli in the sections. All of these show normal morphology. There is trace mesangial staining for IgM, but all other stains in the glomeruli are negative. There is no staining of the tubules or vessels.

Electron Microscopy

One thick section containing three glomeruli is available. These show essentially normal morphology by light microscopy. Ultrastructural examination reveals capillary basement membranes with rather diffuse thinning of the lamina densa. The average thickness of the basement membrane is approximately 190 nm (range 170-210 nm), which is about one-half of the normal thickness for adult glomerular basement membranes. There is no significant effacement of the epithelial foot processes. No electron dense deposits are identified along the capillary basement membranes or in mesangial regions.

Diagnosis and Comments

basement membrane is approximately 190 nm (range 170-210 nm), which is about one-half of the normal thickness for adult glomerular basement membranes. There is no significant effacement of the epithelial foot processes. No electron dense deposits are identified along the capillary basement membranes or in mesangial regions.

Diagnosis: Kidney, needle biopsy – This basement membrane nephropathy. - Mild arteriosclerosis

These biopsy findings are most consistent with thin basement membrane nephropathy. There is no evidence for immune-complex mediated glomerulopathy such as IgA nephropathy. This ultrastructural appearance can also be seen in Alport’s syndrome (hereditary nephritis), and in women it may be the only ultrastructural finding. However, the normal light microscopic appearance is more consistent with thin basement membrane nephropathy.

A normal PaCO2 is 35 to 45 mmHg.

Blood urea nitrogen (BUN) is used as a measure of the glomerular filtration rate and is increased in renal failure.

Hematuria is the presence of blood in the urine.

An infiltrate is an accumulation of cells in the lung parenchyma--this is a sign of pneumonia.