Renal Pathology II

1. Renal Pathology II • Poststreptococcal GN • Other Glomerular Diseases • Acute Pyelonephritis • Vascular Disease • Acute Tubular Necrosis • Kidney Stones (Urolithiasis) • End Stage Renal Disease • Cancer

2. Acute Glomerulonephritis • Acute Nephritic Syndrome • hematuria, red blood cells casts, azotemia, oliguria and hypertension • proteinuria and edema (not as severe as in the nephrotic syndrome) • inflammation/proliferation in the glomeruli • Acute Post-Streptococcal GN

3. Acute Post-Streptococcal GN • occurs at any age, most common ages 6-10 • onset 1-2 weeks after pharyngitis or skin infection • malaise, fever, nausea, oliguria, hematuria (red-brown) • 95% of kids recover completely, 60% of adults • small % develop rapidly progressive GN

4. Acute Post-Streptococcal GN • light: glom’s enlarged, hypercellular, bloodless • endocapillary prolilferation and infiltration by WBC’s (PMN’s, monocytes) • endothelial cells are swollen • tubules contain RBC casts

6. Acute Post-Streptococcal GN • IF: granular deposits of IC’s in the mesangium and along the capillary BM • EM: large, electron dense subepithelial deposits (“humps”) • Complement levels are decreased • group A -hemolytic streptococci • types 12, 4 and 1 are nephritogenic

8. Other Glomerular Diseases • Systemic Lupus Erythematosus (SLE) • Nephritic (sometimes nephrotic) syndrome • IC’s with complement in the glomerular basement membrane and mesangium • IgA Nephropathy (Berger Disease) • Most common glomerular disease in the world • IgA is deposited in the mesangium • Causes hematuria (often microscopic) • Not aggressive, 25-50% develop CRF in 20 yrs

9. Pyelonephritis • disease affecting the tubules, interstitium and renal pelvis Two forms: • Acute Pyelo: often due to bacterial infection • Chronic Pyelo: complex, infection plays a role, but reflux & obstruction may also contribute

10. Acute Pyelonephritis • sudden onset of costovertebral angle pain • dysuria, frequency and urgency • pyuria is often present • good (rapid) response to antibiotics • septicemia is a complication in immunosuppressed patients

11. Acute Pyelonephritis • Kidney surface shows multiple, discrete areas that correspond to abscesses • patchy acute interstitial and tubular inflammation (PMN’s) • glomeruli are not usually involved • papillary necrosis, pyonephrosis, perinephric abscess

14. Acute Pyelonephritis predisposing conditions: Urinary tract obstruction, instrumentation, vesicoureteral reflux, pregnancy, gender and age, preexisting renal lesions, diabetes, immunosuppression

15. Chronic Pyelonephritis

16. Chronic Pyelonephritis

17. Vascular Disease – Benign Nephrosclerosis • Very common problem, elderly patients • Hypertension and diabetes contribute • By itself doesn’t usually cause RF • Narrowing of the lumen of arterioles by thickening and hyalinization • Kidneys size is decreased, cortex is thinned, tubular atrophy, interstitial fibrosis, small glom’s

19. Acute Tubular Necrosis (ATN) • the most common cause of acute renal failure • 2 major causes – Ischemia (most common) and toxic injury (e.g. ethylene glycol) • decreased urine output, azotemia • fluid overload and uremia develops • necrosis of tubular epithelial cells • May be segmental (ischemia) or continuous (toxic)

21. Urolithiasis – Kidney Stones • occur in 5-10 % of US population • peak age is 20-30’s, Males > females • Most common site is renal pelvis or calyx • any part of the urinary tract is possible tho • Small stones (ureter) cause colic • Urinary obstruction, ulceration, bleeding • 80% of stones are unilateral

23. Urolithiasis • 75% of stones composed of calcium oxalate or oxalate admixed with calcium phosphate • 50% of pts have hypercalciuria • hyperparathyroidism, sarcoidosis, increased GI uptake of calcium

24. End Stage Renal Disease • Extensively scarred kidneys in which there is little (or no) evidence of the original disease process • Advanced uremia • Kidneys are quite small ( < 50 gms each) • Glom’s are sclerosed, crowded, tubular atrophy, vascular sclerosis, interstitial fibrosis

26. Tumors • Both benign & malignant tumors occur in the urinary tract • Most common malignant tumors of the Kidney – Renal Cell Carcinoma, Nephroblastoma (Wilms) • Tumors of the lower urinary tract (bladder) are about 2x more common

27. Renal Cell Carcinoma • 2-3% of all cancers in adults (30,000/yr) • most common in 50-60’s, M:F > 2:1 • smoking is a risk factor, familial cases related to a deleted tumor suppressor gene (VHL) • most arise from tubular epithelium • Hematuria and flank pain (dull) common • Also fever and polycythemia (erythropoietin)

28. Renal Cell Carcinoma • tumors are usually solitary & large, yellow with areas of hemorrhage & necrosis • cells have clear cytoplasm (lipid) • Clear cell carcinoma • May extend thru the capsule, invade the pelvis and ureter, invasion of the renal vein is common

31. Wilms Tumor • Nephroblastoma • Occur in children < 5 yrs (between 2-5 yrs) • 4th most common malignancy in kids < 4 yrs • Leukemia, Retinoblastoma, Neuroblastoma • 3 groups of congenital malformations are associated with Wilms tunor (chromosome 11)

32. Wilms Tumor • patients have a large palpable abdominal mass • tumor composed of poorly formed epithelial structures (tubules) and loose mesenchymal stroma • nephrectomy and chemotherapy produces 90% 2-year survival

33. Wilm Tumor

35. What the hell does it all mean?