CRP-54
CRP-54
Clinical History
The patient is a 28-year-old male. No clinical history given.
Gross Description
Received is Zeus fixative are two cores of tissue measuring 1 and 1.5 mm in greatest dimension. These are entirely submitted for immunofluorescence. Received in Carson's fixative is one core of tissue measuring 6 mm in length. A 1-mm fragment is submitted for EM, and the remaining tissue is processed for light microscopy.
Pathology
Case CRP-054 H&E
Case CRP-054 PASH
Case CRP-054 Silver
Microscopic Description
Light Microscopy
The specimen consists of a fragment of renal cortex that contains 17 glomeruli in the three levels examined. These are all similar and show essentially normal morphology. However, there are striking changes in the tubule-interstitial compartment. Many of the tubules show marked dilatation and contain large eosinophilic casts. Some of the casts are fractured, and others show a multilamellar appearance. There is a prominent mononuclear cell reaction to these casts, and occasional multinuclear giant cells are also present in some of the tubules. The tubular epithelium is flattened and degenerated. Even in the tubules that do not contain cast5, the tubular epithelium show degenerative changes. There is moderate interstitial fibrosis. Mononuclear cells, primarily lymphocytes, are 5cattered throughout the interstitium, and occasional examples of emperipolesis are identified. A few plasma cells are also present, but no eosinophils are identified. The arterioles in the biopsy are unremarkable.
Immunofluorescence
There are three glomeruli in these sections. All good preservation. There is no glomerular staining for IgG, IgM, IgA, Clq, C3 or light chains. The tubular casts stain for lambda light chain predominantly around the periphery of the casts. There is no kappa staining of the casts. There is no staining of the vessels.
Electron Microscopy
One thick section containing two glomeruli is available. These two glomeruli show good preservation. However, the tubules in the section contain casts and show epithelial degeneration similar to those described under light microscopy. Ultrastructural examination confirms the normal histology of the glomeruli. There is no significant mesangial expansion or thickening of the capillary basement membranes. Foot processes are generally well preserved. No electron dense deposits are identified in the mesangial regions or along the capillary basement membrane. Few tubules contain electron dense casts, and mononuclear are closely applied to the casts focally. Tubular epithelium shows degenerative changes.