Match each clinical vignette describing a patient with a renal disorder to the most characteristic histopathologic or immunofluorescent finding expected on their renal biopsy.
- A 62-year-old man with a history of chronic sinusitis and epistaxis presents with rapidly progressive oliguria. Urinalysis shows dysmorphic red blood cells and red blood cell casts. Serum testing is positive for PR3-ANCA.Glomerular crescent formation composed of proliferating parietal epithelial cells and macrophages, with a lack of significant immunoglobulin or complement deposition.
- A 34-year-old woman with a history of recurrent early fetal loss and a previous deep vein thrombosis develops sudden oliguria and severe hypertension. Laboratory studies reveal thrombocytopenia and schistocytes on a peripheral blood smear.Glomerular capillary and arteriolar fibrin thrombi, endothelial cell swelling, and subendothelial widening without significant immune complex deposition.
- A 55-year-old man with severe, poorly controlled rheumatoid arthritis for 20 years presents with profound peripheral edema. Laboratory studies show a serum albumin of 2.1 g/dL and a 24-hour urine protein excretion of 6.5 g.Amorphous, extracellular fibrillar deposits in the mesangium and capillary walls that demonstrate apple-green birefringence under polarized light after Congo red staining.
- A 28-year-old man develops gross hematuria 48 hours after the onset of a mild upper respiratory tract infection. His serum complement levels are normal. He reports a similar self-resolving episode three years ago.Prominent, granular deposition of IgA and C3 localized primarily within the glomerular mesangium.
- A 60-year-old man with recently diagnosed lung adenocarcinoma presents with sudden-onset left flank pain, a new left-sided varicocele, and massive lower extremity edema. His urine protein-to-creatinine ratio is 8.0 g/g.Diffusely thickened glomerular basement membranes with subepithelial electron-dense deposits exhibiting a 'spike and dome' appearance on silver stain.
Answer
The correct pairings match Granulomatosis with polyangiitis to pauci-immune crescents, Antiphospholipid syndrome TMA to fibrin thrombi, Rheumatoid arthritis-induced amyloidosis to Congo red positivity, IgA nephropathy to mesangial IgA, and Membranous nephropathy (with renal vein thrombosis) to 'spike and dome' subepithelial deposits.
Each clinical vignette provides distinct clues to a specific nephropathy. Granulomatosis with polyangiitis presents with systemic vasculitis (sinusitis) and PR3-ANCA, correlating with pauci-immune crescents. Antiphospholipid syndrome can trigger a secondary thrombotic microangiopathy, characterized by fibrin thrombi and schistocytes without immune complexes. Chronic inflammation from rheumatoid arthritis causes AA amyloidosis, definitively diagnosed via Congo red stain. IgA nephropathy uniquely presents with synpharyngitic hematuria and mesangial IgA deposits. Lastly, membranous nephropathy is heavily associated with solid malignancies and has a high propensity for renal vein thrombosis (causing sudden flank pain and a new left varicocele), showing subepithelial 'spike and dome' deposits on biopsy.
Step-by-Step Solution
Key Concept
Correlation of complex clinical nephrology syndromes and their associated complications with pathognomonic renal biopsy findings.
Estimated Time:3m 0s