View source for CRP-23

'''CRP-23'''
==Clinical History==
The patient is a 56 year old man. BUN 30, creatinine 1.7, urinary protein 6 g/24 hr. Low C3, positive anti-double stranded DNA. Suspect lupus nephritis.

==Gross Description==
Received in transport media are two cores measuring 16 and 10 mm in length and 1 mm in diameter. Two 1-mm pieces are taken for EM. Two pieces measuring 4 and 7 mm in length are taken for immunofluorescence, and the remainder is processed for light microscopy.

==Pathology==
===Case CRP-023 H&E===
<peir-vm>specialcrp/CRP-023_HE</peir-vm>
===Case CRP-023 PASH===
<peir-vm>specialcrp/CRP-023_PASH</peir-vm>
===Case CRP-023 Silver===
<peir-vm>specialcrp/CRP-023_Silver</peir-vm>
===Case CRP-023 Trichrome===
<peir-vm>specialcrp/CRP-023_Trichrome</peir-vm>

<div class="usermessage mw-customtoggle-diagnosis" style="cursor:pointer"> Microscopic Description, Immunofluorescence, and Electron Microscopy</div>
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==Microscopic Description==
===Light Microscopy===
The specimen consist of two fragments of renal cortex that contain 47 glomeruli in the three levels examined. Two of these are obsolete. The remaining glomeruli are similar and show marked diffuse proliferation and accentuation of the lobular architecture. Several of the glomeruli also demonstrate segmental necrosis, and a number of thick eosinophilic capillary loops (wire loops) are noted. There are also numerous examples of mesangial interposition, which are especially obvious with the silver stain. However, no spike formation is identified along the epithelial surfaces. One small epithelial crescent is identified. There is diffuse mild interstitial fibrosis, although tubular atrophy is only mild and focal. There are no inflammatory infiltrates. The vessels are unremarkable.

===Immunofluorescence===
There are 13 glomeruli in the sections. There is diffuse granular staining in the mesangial regions and along the capillary basement membranes that is graded 2+ for IgG, IgM, IgA, Clq, C3 and light chains. There is also strong nuclear staining in the tubular epithelium for IgG and kappa light chain. Focal albumin droplets are noted in some of the tubular lumina. There is no staining of the tubular basement membranes or vessels.

===Electron Microscopy===
Two thick sections containing a total of five glomeruli are available. These are similar and show diffuse mesangial and endocapillary cell proliferation with compression of the capillary lumina. Ultrastructural examination confirms the presence of mesangial interposition, and numerous· large subendothelial deposits are noted. There are also many immune complex deposits in the mesangial regions. No subepithelial or intramembranous deposits are noted. There is diffuse effacement of the visceral cell foot processes.

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<spoiler text="Diagnosis and Comments">
Kidney, needle biopsy - Diffuse proliferative lupus nephritis, WHO class IV.

These findings are most consistent with diffuse proliferative lupus nephritis. Although the glomerular lesion is quite active, the degree of interstitial fibrosis is still relatively mild.

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