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Anatomic pathology > Kidney > Flashcards

Flashcards in Kidney Deck (379):
1

Infantile polycystic kidney disease: Inheritance.

Autosomal recessive.

2

Infantile polycystic kidney disease:

A. Gene and its location.
B. Encoded protein.

A. PKHD1 on chromosome 6p21-23.

B. Polyductin / fibrocystin.

3

Infantile polycystic kidney disease: Presentation (2).

Abdominal distention.

Stillbirth or early neonatal death in most cases.

4

Infantile polycystic kidney disease: Associated abnormalities (2).

Pulmonary hypoplasia.

Congenital hepatic fibrosis.

5

Infantile polycystic kidney disease: Gross pathology.

Massive enlarged kidneys with smooth surface.

6

Infantile polycystic kidney disease:

A. Location and arrangement of cysts.
B. Calyceal system.

A. Cortex and medulla; oriented perpendicular to the renal capsule.

B. Normal.

7

Infantile polycystic kidney disease: Histopathology (2).

Dilated collecting ducts lined by bland cuboidal cells.

Nephrons appear normal.

8

Medullary cystic disease: Presentation.

Renal dysfunction in childhood:

− Polyuria and polydipsia.
− Uremia.
− Growth retardation.

9

Medullary cystic disease: Gross pathology.

Kidneys are small; both are affected.

10

Medullary cystic disease: Number, size, and location of cysts.

Many.

Up to 2 cm in diameter.

Corticomedullary junction.

11

Medullary sponge kidney: Presentation.

Found in children or adolescents.

12

Medullary sponge kidney: Gross pathology.

Kidneys are typically of normal size.

13

Medullary sponge kidney: Size and location of cysts.

Less than 0.5 cm.

Medullary pyramids, renal papillae; communication with collecting ducts.

14

Medullary sponge kidney: Prognosis.

Renal function is usually normal.

Progression to end-stage renal disease occurs rarely.

15

Renal dysplasia: Clinical significance (2).

Dysplastic kidneys usually do not function.

Nearly always accompanied by other abnormalities of the urinary tract.

16

Renal dysplasia: Presentation (2).

If large: Palpable mass.

If small: May remain asymptomatic for many years.

17

Renal dysplasia: Possible outcomes in utero (2).

Oligohydramnios with Potter's sequence.

Death from pulmonary hypoplasia.

18

Renal dysplasia: Gross pathology.

Distorted kidneys with variable of cysts.

19

Renal dysplasia: Histopathology (3).

Disorganized renal parenchyma containing cartilage.

Dysplastic ducts lined by columnar epithelium and surrounded by spindle cells.

Cystic spaces lined by flat epithelium.

19

Adult polycystic kidney disease: Type of inheritance.

Autosomal dominant.

20

Adult polycystic kidney disease: Genes, locations, proteins (2).

PKD1, chromosome 16, polycystin 1.

PKD2, chromosome 4, polycystin 2.

21

Presentation of adult polycystic kidney disease:

A. Age of patient.
B. Laboratory abnormalities (2).

A. Fourth or fifth decade.

B. Hematuria or proteinuria.

22

Adult polycystic kidney disease: Extrarenal manifestations (4).

Berry aneurysms.

Colonic diverticula.

Cysts in pancreas, liver.

Cardiac valvular abnormalities.

23

Adult polycystic kidney disease: Gross pathology (2).

Early: Normal-sized kidneys with a few cysts.

Later: Markedly enlarged kidneys with irregular contour due to cysts.

24

Adult polycystic kidney disease: Size and location of cysts.

From a few millimeters to several centimeters in diameter.

Cortical and medullary.

25

Adult polycystic kidney disease: Histopathology (2).

Cysts: Flat or cuboidal epithelial lining.

Parenchyma: Fibrosis, atrophy.

26

Adult polycystic kidney disease: Complications (2).

End-stage renal disease.

Renal-cell carcinoma.

27

Acquired cystic disease: Presentation (2).

Usually asymptomatic.

Cysts develop in the setting of chronic renal failure, usually dialysis dependent.

28

Acquired cystic disease:

A. Inheritance.
B. Extrarenal manifestations.

A,B. None.

29

Acquired cystic disease:

A. Gross pathology.
B. Size and location of cysts.

A. Kidneys are moderately enlarged at the most.

B. Variable as in ADPKD; cortical.

30

Acquired cystic disease: Parenchymal changes.

Fibrosis, atrophy.

31

Acquired cystic disease: Complication.

Renal-cell carcinoma (can arise in a cyst or in the parenchyma).

32

Xanthogranulomatous pyelonephritis: Clinical significance.

Can form mass(es) and mimic renal neoplasia.

33

Xanthogranulomatous pyelonephritis: Most common agents (2).

Proteus spp.

E. coli.

34

Xanthogranulomatous pyelonephritis: Associated renal disease.

Calculi.

35

Xanthogranulomatous pyelonephritis: Progression.

Begins in renal pyramids and spreads to renal pelvis and then to capsule and to perinephric fat.

36

Xanthogranulomatous pyelonephritis: Gross-pathologic types (2).

Diffuse: More common.

Segmental: Polar; occurs in children.

37

Xanthogranulomatous pyelonephritis: Histopathologic zones of a nodule.

Inner: Necroinflammatory debris that is rich in neutrophils.

Outer: Lipid-laden macrophages.

Outermost (sometimes): Multinucleate giant cells, spindled fibroblasts.

38

Xanthogranulomatous pyelonephritis: Histopathologic pitfalls (2).

Lipid-laden macrophages may be confused with RCC.

Multinucleate giant cells and spindled fibroblasts may be confused with sarcomatoid carcinoma.

39

Angiomyolipoma: Inheritance.

Most tumors are sporadic.

40

Angiomyolipoma: Relation to tuberous sclerosis (2).

20% of tumors as associated with TS.

Most patients with TS develop an angiomyolipoma.

41

Angiomyolipoma: Relation of inheritance to gross pathology (2).

Sporadic: Large, single, unilateral.

TS: Smaller, multiple, bilateral.

42

Angiomyolipoma: Components.

Thick-walled hyalinized blood cells.

Smooth muscle.

Mature fat.

43

Angiomyolipoma: Possible atypical gross findings (2).

Presence of tumor in renal vein or in regional lymph nodes.

44

Angiomyolipoma: Possible atypical histopathologic features (3).

Nuclear pleomorphism.

Mitotic activity.

Epithelioid smooth-muscle cells.

45

Angiomyolipoma: Immunohistochemistry (2,1).

Positive: Melanocytic markers, smooth-muscle markers.

Negative: Epithelial markers.

46

Angiomyolipoma: Importance of careful sampling.

To exclude a coexisting renal-cell carcinoma.

47

Epithelioid angiomyolipoma:

A. Behavior.
B. Presentation.

A. Potentially malignant but unlikely to metastasize.

B. Flank pain or no symptoms.

48

Epithelioid angiomyolipoma: Radiography.

Lack of fat imparts resemblance to RCC.

49

Epithelioid angiomyolipoma: Association.

Tuberous sclerosis.

50

Epithelioid angiomyolipoma: Gross pathology (3).

Solid, hemorrhagic cut surface.

More likely than conventional angiomyolipoma to be necrotic.

51

Epithelioid angiomyolipoma: Cellular components (3).

Short spindle cells.

Large epithelioid cells.

Pleomorphic cells that resemble ganglion cells or multinucleate giant cells.

52

Epithelioid angiomyolipoma: Immunohistochemistry.

Similar to that of conventional angiomyolipoma.

53

Epithelioid angiomyolipoma: Significance of invasion of renal vein.

Observed more frequently in clinically malignant cases.

54

Epithelioid angiomyolipoma: Sites of metastasis (4).

Lymph nodes.

Lungs.

Liver.

Mesentery.

55

Metanephric adenoma:

A. Age group.
B. Possible "paraneoplastic" finding.

A. Most common in the fifth decade.

B. Polycythemia.

56

Metanephric adenoma: Cytology.

Small, bland cells with dark nuclei and scant cytoplasm.

57

Metanephric adenoma: Histologic architecture (3).

Small, tightly packed acini in an acellular stroma.

Variations:
− Papillary foci.
− Solid (blastema-like) foci.

58

Metanephric adenoma: Immunohistochemistry (3,2).

Positive: Pancytokeratin, CD57, WT-1.

Negative: CK7, AMACR, CD56.

59

Metanephric adenoma: Electron microscopy (2).

Basal lamina, microvilli.

60

Metanephric adenoma: Mutation.

V600E in BRAF.

61

Metanephric adenoma: Behavior.

Benign.

62

The nuclear grading system of Fuhrman.

1: 20 μm, pleomorphic, open or dark chromatin, macronucleolus.

63

Papillary adenoma: Associations (3).

Long-term hemodialysis.

Chronic pyelonephritis.

von Hippel−Lindau syndrome.

64

Papillary adenoma:

A. Size.
B. Histologic architectural patterns (3).

A. Less than 5 mm.

B. Tubular, papillary, or both.

65

Papillary adenoma: Cytology (2).

Bland cuboidal cells.

Nuclei correspond with Fuhrman grades 1 and 2.

66

Papillary adenoma: Other histologic features (2).

Psammomatous calcifications.

Foamy histiocytes.

67

Papillary adenoma: Disqualifying cytologic feature.

Clear cytoplasm.

68

Papillary adenoma: Immunohistochemistry (2,1).

Positive: CK7, AMACR.

Negative: WT-1.

69

Papillary adenoma: Mutations (3).

+7, +17, -Y.

70

Renal oncocytoma: Radiography.

Central scar ("spoke-wheel" appearance).

71

Renal oncocytoma: Histologic patterns (3).

Classic: Well-defined nests of oncocytes.

Tubulocystic: Tubules and cysts contain eosinophilic secretions.

Mixed: Nests and tubules.

72

Renal oncocytoma: "Tolerable" histopathologic anomalies (3).

Occasional smudged nuclei.

Occasional clear cells.

Focal extension into perinephric fat.

73

Renal oncocytoma: Features that are incompatible with the diagnosis (4).

Gross extension into the perinephric fat.

Papillae.

Sarcomatoid or spindle-cell areas.

Atypical mitotic figures.

74

Renal oncocytoma: Immunohistochemistry (4,1),

Positive: CK7, S100, E-cadherin, claudin 8 (cytoplasmic).

Negative: Vimentin.

75

Renal oncocytoma: Special stain.

Negative: Hale's colloidal iron.

76

Renal oncocytoma: Mutation.

t(5;11) in some cases.

77

Renal oncocytoma vs. clear-cell RCC with eosinophilic cytoplasm: Immunohistochemistry (3).

Clear-cell RCC expresses vimentin but neither CK7 nor E-cadherin.

78

Renal oncocytosis: Causes (2).

Sporadic.

Chronic renal failure.

79

Renal oncocytoma: Putative origin.

Intercalated cells of the collecting ducts.

80

Birt-Hogg-Dubé syndrome: Renal tumor.

Combines features of renal oncocytoma and chromophobe RCC.

81

Renal-cell carcinoma, clear-cell type: Classic presentation.

Pain, flank mass, hematuria: Reported in only 10% of patients.

82

Renal-cell carcinoma, clear-cell type: Genes (4).

VHL.

PBRM1.

BAP1.

SETD2.

83

Renal-cell carcinoma, clear-cell type vs. clear-cell papillary renal-cell carcinoma: Immunohistochemistry.

Clear-cell papillary renal-cell carcinoma . . .

− Positive: CK7 and keratin 34βE12.
− Negative: CD10, AMACR.

Both tumors express CA9.

84

Renal-cell carcinoma, clear-cell type vs. adrenocortical carcinoma: Immunohistochemistry (2).

Adrenocortical carcinoma . . .

− Positive: Inhibin, calretinin.
− Negative: EMA, cytokeratins.

85

Clear-cell papillary renal-cell carcinoma: Cytology (2).

Clear cells with low-grade nuclei.

Nuclei are oriented away from the basement membrane and toward the lumen.

86

Renal-cell carcinoma, papillary type: Syndrome, gene, location.

Hereditary papillary RCC syndrome: c-met on chromosome 7q31.

87

Renal-cell carcinoma, papillary type: Gross pathology (2).

Fibrous pseudocapsule.

May be multifocal or bilateral.

88

Renal-cell carcinoma, papillary type, type I: Histopathology.

Papillae are lined by a single layer of cells with low-grade nuclear features and scant cytoplasm.

89

Renal-cell carcinoma, papillary type, type II: Histopathology.

Papillae are lined by pseudostratified cells of higher nuclear grade and much cytoplasm.

90

Renal-cell carcinoma, papillary type: Cytokeratins.

CK7 is expressed by 80% of tumors of type I and by 20% of tumors of type II.

91

Renal-cell carcinoma, papillary type: Additional immunohistochemical stains (3).

Positive: RCC antigen, CD10, PAX8.

92

Renal-cell carcinoma, papillary type: Mutations (3).

+7, +17, -Y.

No mutation of VHL.

93

Renal-cell carcinoma, chromophobe type: Syndrome.

Birt-Hogg-Dubé syndrome.

94

Renal-cell carcinoma, chromophobe type: Histopathology.

Thick cell membranes resembling walls of plant cells.

Koilocyte-like wrinkled nuclei with halo.

Thick-walled, hyalinized blood vessels.

95

Renal-cell carcinoma, chromophobe type: Histopathologic types.

Classic: Pale cytoplasm.

Eosinophilic: Intensely eosinophilic cytoplasm.

96

Renal-cell carcinoma, chromophobe type: Electron microscopy (2),

Classic: Many microvesicles.

Eosinophilic: Many mitochondria.

97

Renal-cell carcinoma, chromophobe type vs. oncocytoma: Stains (3).

Renal-cell carcinoma, chromophobe type . . .

− CK7, Hale's colloidal iron: Diffusely positive.
− S100A1: Not expressed.

98

Renal-cell carcinoma, chromophobe type: Prognosis.

Significantly better than that of clear-cell RCC.

99

Multilocular cystic renal-cell carcinoma: Gross pathology.

Concysts entirely of sists filled with serous or hemorrhagic fluid.

100

Multilocular cystic renal-cell carcinoma: Histopathology.

Cysts are lined by one layer of epithelium.

Fibrous septa contain small clusters of clear cells.

101

Multilocular cystic renal-cell carcinoma vs. renal-cell carcinoma with cystic change.

The former contains no solid, expansile tumor nodules of any size.

102

Multilocular cystic renal-cell carcinoma: Prognosis.

Excellent.

103

Carcinoma of the collecting ducts: Location.

Medulla.

104

Carcinoma of the collecting ducts: Histopathologic architecture (2).

Tubular or tubulopapillary structures with tapered ends.

Inflamed desmoplastic stroma.

105

Carcinoma of the collecting ducts: Cytology (4).

High-grade nuclei.

Hobnail appearance of cells that line glands.

Many mitotic figures.

Cytoplasm may contain mucin.

106

Carcinoma of the collecting ducts: Adjacent renal tissue.

Shows epithelial dysplasia.

107

Carcinoma of the collecting ducts: Immunohistochemistry (5,1).

Positive: HMWCK, CK7, CEA, peanut agglutinin, Ulex europaeus agglutinin.

Negative: CD10.

108

Carcinoma of the collecting ducts vs. papillary renal-cell carcinoma: Immunohistochemistry.

Papillary renal-cell carcinoma does not express HWMCK or Ulex europaeus agglutinin.

109

Carcinoma of the collecting ducts vs. urothelial carcinoma with glandular differentiation.

Urothelial carcinoma with glandular differentiation is more likely if the tumor arises in the calyces or the renal pelvis.

110

Carcinoma of the collecting ducts: Prognosis.

Poor; one third of patients present with metastases.

111

Renal medullary carcinoma: Epidemiology.

Near all patients have sickle-cell trait or the disease.

Patients are typically under 40 years old.

112

Renal medullary carcinoma: Gross pathology.

Arises in the medulla but tends to extend into the calyces and often into the perinephric fat.

113

Renal medullary carcinoma: Histopathologic patterns (3).

Areas that resemble yolk-sac tumor at low power.

Areas that resemble adenoid-cystic carcinoma.

Solid sheets.

114

Renal medullary carcinoma: Cytology.

Poorly differentiated cells with vesicular nuclei and a large nucleolus.

115

Renal medullary carcinoma: Stroma.

Desmoplastic and inflamed and may contain mucin or edema.

116

Renal medullary carcinoma: Blood vessels.

Contain sickle cells.

Usually invaded by the tumor.

117

Renal medullary carcinoma: Immunohistochemistry (1,2).

Positive: Cytokeratins.

Negative: HMWCK, INI-1.

118

Renal medullary carcinoma: Prognosis.

Most patients are dead within 1 year.

119

Mucinous tubular and spindle-cell carcinoma:

A. Presentation.
B. Behavior.

A. Usually asymptomatic.

B. Low-grade carcinoma with a good prognosis.

120

Mucinous tubular and spindle-cell carcinoma: Histopathologic components (3).

Elongated and compressed tubules.

Spindle-shaped epithelial cells.

Extracellular mucinous Krappe.

121

Mucinous tubular and spindle-cell carcinoma: Cytology.

Bland cells with inconspicuous nucleoli.

122

Mucinous tubular and spindle-cell carcinoma: Immunohistochemistry (2,2).

Positive: Cytokeratins, AMACR.

Negative: CD10, villin (markers of proximal tubules).

123

Renal-cell carcinoma with translocations involving TFE3: Epidemiology.

Affects mainly children and young adults.

124

Renal-cell carcinoma with translocations involving TFE3: Location of TFE3 gene.

Xp11.2.

125

Renal-cell carcinoma with translocations involving TFE3: Most common translocation partners of TFE3 (2).

ASPL (17q25): Advanced stage at presentation.

PRCC (1q21).

126

Renal-cell carcinoma with translocations involving TFE3: Histopathologic patterns (2).

Papillary and nested.

127

Renal-cell carcinoma with translocations involving TFE3: Cytology (4).

Clear or pink cytoplasm.

Discrete cell borders.

Vesicular chromatin.

Large nucleoli.

128

Renal-cell carcinoma with translocations involving TFE3: Extracellular features (2).

Psammoma bodies.

Hyaline nodules.

129

Renal-cell carcinoma with translocations involving TFE3: Effect of translocation partner on histopathology (2).

ASPL: Cells have more cytoplasm; more psammoma bodies, more hyaline nodules.

PRCC: Less of all three.

130

Renal-cell carcinoma with translocations involving TFE3: Immunohistochemistry (4).

Positive: TFE3, cathepsin K, CD10, RCC.

131

Renal-cell carcinoma with t(6;11):

A. Epidemiology.
B. Prognosis.

A. Affects mainly children and young adults.

B. Similar to that of conventional RCC.

132

Renal-cell carcinoma with t(6;11): Gene.

TFEB on chromosome 6p21.

133

Renal-cell carcinoma with t(6;11): Cellular components (2).

Polygonal epithelioid cells with discrete borders.

Smaller cells with dark nuclei, forming clusters around hyaline matter.

Mitotic figures are rare.

134

Renal-cell carcinoma with t(6;11): Architecture.

Tubular, micropapillary.

135

Renal-cell carcinoma with t(6;11): Immunohistochemistry (2,2).

Positive: TFEB, melanoma markers.

Negative: TFE, epithelial markers.

136

Renal-cell carcinoma associated with neuroblastoma: Timing.

Diagnosed around 10 years after the original diagnosis of neuroblastoma.

137

Sarcomatoid differentiation in renal-cell carcinoma:

A. Setting.
B. Significance.

A. Can occur in any type of renal-cell carcinoma.

B. Imparts poor prognosis.

138

Sarcomatoid differentiation in renal-cell carcinoma: Histopathology (3).

Nondescript spindle cells.

May resemble MFH.

May resemble leiomyosarcoma or other differentiated sarcoma.

139

Sarcomatoid differentiation in renal-cell carcinoma: Immunohistochemistry.

May express epithelial markers and PAX8.

May not express other markers that are expressed in the better-differentiated parts of the tumor.

140

Renal tumors that contain spindle cells (4).

Any carcinoma with sarcomatoid differentiation.

Any carcinoma (esp. conventional) containing a scar.

Mucinous tubular and spindle-cell carcinoma.

Primary renal sarcoma.

141

Renal-cell carcinoma, unclassified: Examples of histopathology (3).

A tumor combining features of recognized renal tumors.

A tumor showing sarcomatoid differentiation only.

A high-grade tumor.

142

Cystic nephroma: Typical patient.

Middle-aged female.

143

Cystic nephroma: Presentation and behavior.

Asymptomatic and benign.

144

Cystic nephroma: Gross pathology.

Consists of many cystic spaces that do not communicate with the renal pelvis.

145

Cystic nephroma: Histopathology (2).

Cysts lined by bland cells.

Ovarian-type or hyalinized stroma.

146

Cystic nephroma: Disqualifying histopathologic feature.

Nephronic elements in the stroma.

147

Cystic nephroma: Immunohistochemistry.

Ovarian-type stroma expresses ER and PR.

148

Cystic nephroma: Significance of pediatric type.

Considered a variant of nephroblastoma.

149

Cystic nephroma vs. nephrogenic adenoma vs. metanephric adenoma.

Cystic nephroma: Bland cysts and ovarian-type stroma.

Nephrogenic adenoma: Renal-tubular-like proliferation outside the kidneys.

Metanephric adenoma: Small acini consisting of small, dark cells.

150

Mixed epithelial and stromal tumor: Epidemiology and putative etiology.

Mostly in females; estrogen imbalance.

151

Mixed epithelial and stromal tumor: Gross pathology (2).

Central location in the kidney.

Contains cystic (epithelial) and solid (stromal) areas.

152

Mixed epithelial and stromal tumor vs. cystic nephroma.

MEST
− Epithelial component: Tubules as well as cells.
− Stromal component: Grossly evident; histologically more variable (e.g. fat, smooth muscle).

Both tumors are considered part of the same spectrum.

153

Tubulocystic carcinoma: Typical patient.

Middle-aged man.

154

Tubulocystic carcinoma: Gross pathology (3).

Entirely cystic, resembling bubble wrap.

Well circumscribed but has no capsule.

155

Tubulocystic carcinoma: Histopathology.

Closely packed cysts separated by delicate septa or a fibrotic stroma.

No tumor cells in those septa.

156

Tubulocystic carcinoma: Cytology.

Cells resemble hobnails and contain large nucleoli.

157

Tubulocystic carcinoma: Immunohistochemistry (2,1).

Positive: CD10, AMACR.

Negative: CD7.

158

Tubulocystic carcinoma vs. multilocular cystic renal-cell carcinoma.

Multilocular cystic renal-cell carcinoma: Nests of clear cells in the septa.

159

Clear-cell tubulopapillary renal-cell carcinoma: Behavior.

Low grade, low stage.

160

Clear-cell tubulopapillary renal-cell carcinoma: Gross pathology.

Cystic; fibrous capsule.

161

Clear-cell tubulopapillary renal-cell carcinoma: Architecture (3).

Papillae, tubules, cysts.

162

Clear-cell tubulopapillary renal-cell carcinoma: Cytology.

Clear cytoplasm.

Bland nuclei (Fuhrman grade 1 or 2).

Nuclei are oriented toward the lumens and away from the basement membranes.

163

Clear-cell tubulopapillary renal-cell carcinoma: Cytogenetics.

No +7, +17, -Y.

No -3p.

164

Clear-cell tubulopapillary renal-cell carcinoma: Immunohistochemistry (2,2).

Positive: CK7 (membranous), CA9.

Negative: AMACR, CD10.

165

Hereditary leiomyomatosis:

A. Inheritance.
B. Tumors (3).

A. Autosomal dominant.

B. Leiomyomas, uterine leiomyosarcoma, renal-cell carcinoma.

166

Hereditary leiomyomatosis: Gene and its location.

Fumarate hydratase on 1q42.

167

Renal-cell carcinoma of hereditary leiomyomatosis: Architecture.

Similar to that of papillary RCC, type II.

168

Renal-cell carcinoma of hereditary leiomyomatosis: Cytology.

Large nucleus contains a very large, red nucleolus with a clear halo.

169

Renal-cell carcinoma of hereditary leiomyomatosis: Immunohistochemistry.

Positive: 2SC (2-succinylcysteine).

170

Renal-cell carcinoma of hereditary leiomyomatosis: Prognosis.

Poor.

171

Birt-Hogg-Dubé syndrome: Skin tumors (3).

Fibrofolliculoma.

Trichodiscoma.

Acrochordons.

172

Birt-Hogg-Dubé syndrome: Gene, location, product.

BHD, 17p11.2, folliculin.

173

Renal-cell carcinoma associated with Birt-Hogg-Dubé syndrome: Histopathology (3).

Oncocytoma + chromophobe RCC.

Oncocytosis outside the tumor.

Clear cells without wrinkled nuclei.

174

Renal-cell carcinoma associated with Birt-Hogg-Dubé syndrome: Immunohistochemistry (3).

Positive: CK7, CD117, parvalbumin.

175

Renal-cell carcinoma associated with Birt-Hogg-Dubé syndrome: Prognosis.

Excellent; no aggressive behavior reported.

176

SDH syndrome: Tumors (3).

Paraganglioma / pheochromocytoma.

Gastrointestinal stromal tumor.

Renal-cell carcinoma.

177

SDH syndrome: Genes.

SDHB, SDHC, SDHD: Subunits of succinate dehydrogenase in Krebs' cycle.

178

Renal-cell carcinoma of SDH syndrome: Mean age at presentation.

33 years.

179

Renal-cell carcinoma of SDH syndrome: Histopathology (2).

Mutation in SDHB: Consists of oncocytes containing large vacuoles and bland nuclei.

Mutation in SDHC or SDHD: Resembles clear-cell RCC.

180

Renal-cell carcinoma of SDH syndrome: Prognosis.

May be aggressive, especially in younger patients.

181

Renal-cell carcinoma associated with acquired cystic disease: Risk factors (2).

Male gender.

Long-term dialysis.

182

Renal-cell carcinoma associated with acquired cystic disease: Architecture.

Mixture of sheets, nests, tubulopapillary areas, and cystic areas.

183

Renal-cell carcinoma associated with acquired cystic disease: Cytology (2).

Eosinophilic cytoplasm.

Nuclei of Fuhrman grade 3.

184

Renal-cell carcinoma associated with acquired cystic disease: Intracellular features (2).

Microlumens, hemosiderin.

185

Renal-cell carcinoma associated with acquired cystic disease: Extracellular feature.

Oxalate crystals.

186

Renal-cell carcinoma associated with acquired cystic disease: Immunohistochemistry (2,3).

Positive: AMACR, CD10.

Negative: CA9, PAX8, CK7.

187

Renal medullary interstitial-cell tumor / medullary fibroma: Presentation.

Asymptomatic; found incidentally.

188

Renal medullary interstitial-cell tumor / medullary fibroma: Histopathology.

Medullary tubules entrapped in a paucicellular matrix that is collagenous or myxoid.

189

Renal medullary interstitial-cell tumor / medullary fibroma: Cell of origin.

Renal medullary interstitial cell, which helps to control the blood pressure.

190

Juxtaglomerular-cell tumor: Presentation.

Hypertension.

191

Juxtaglomerular-cell tumor: Laboratory findings (3).

Elevated plasma renin.

Elevated aldosterone.

Hypokalemia.

192

Juxtaglomerular-cell tumor: Location.

Renal cortex.

193

Juxtaglomerular-cell tumor: Architecture (3).

Trabeculae or glomeruloid formations.

Myxoid stroma containing lymphocytes.

Hemangiopericytoma-like vasculature.

194

Juxtaglomerular-cell tumor: Cytology (3).

Polygonal or spindle shape.

Moderate or abundant pink, granular cytoplasm.

Bland nuclei.

195

Juxtaglomerular-cell tumor: Immunohistochemistry (2,3).

Positive: CD31, actins.

Negative: Cytokeratins, desmin, melanoma markers.

196

Juxtaglomerular-cell tumor: Electron microscopy.

Rhomboid crystals of renin.

197

Juxtaglomerular-cell tumor: Prognosis.

Never reported to recur or metastasize.

198

Nephroblastoma: Age group.

Children below the age of 6.

199

Nephroblastoma: Syndromes (4).

WAGR.

Denys-Drash.

Beckwith-Wiedemann.

Familial neuroblastoma.

200

WAGR syndrome:

A. Components.
B. Mutation.

A. Wilms' tumor, aniridia, genital anomalies, mental retardation.

B. del(11p13), including WT1.

201

Denys-Drash syndrome: Mutation.

Point mutation in WT1.

202

Beckwith-Wiedemann: Gene.

WT2 on 11p15.

203

Nephroblastoma: Typical presentation.

Abdominal mass or tenderness.

204

Nephroblastoma:

A. Histological components (3).
B. Variation.

A. Blastemal, stromal, epithelial.

B. Only two or only one component may be represented.

205

Nephroblastoma: Blastema.

Consists of small, round, blue cells with coarse chromatin.

206

Nephroblastoma: Stroma (2).

Myxoid or fibromyxoid.

May show differentiation toward skeletal muscle, cartilage, etc.

207

Nephroblastoma: Epithelial component (2).

Poorly or well-formed tubules and papillae.

Squamous or mucinous foci may be seen.

208

Nephroblastoma: Definition of nuclear anaplasia (3).

Polyploidy

− or −

Multipolar mitotic figures

− or −

Greater-than-threefold variation in nuclear size.

209

Nephroblastoma: Significance of nuclear anaplasia.

Predicts responsiveness to chemotherapy.

210

Nephroblastoma: Immunohistochemistry for WT1.

Blastema and undifferentiated epithelium: Diffuse expression.

Stroma: Little or no expression.

Differentiated epithelium: Variable.

211

Nephroblastoma: Distinction from other tumors of small, round, blue cells (2).

IHC: Expression of WT-1 by nephroblastoma.

EM: Variety of organelles in blastemal cells of nephroblastoma.

212

Nephroblastoma: Sites of metastasis (3).

Lymph nodes, liver, lung.

213

Nephroblastoma: Prognosis (2).

About 90% of cases get cured.

Younger patients do better.

214

Nephrogenic rest:

A. Significance.
B. State of multiplicity.

A. Increased likelihood of contralateral nephroblastoma.

B. Nephroblastomatosis.

215

Nephroblastoma: Histopathology (2).

Perilobar type: Mainly blastema and tubules; very little stroma.

Intralobar type: Rich in stroma.

216

Cystic partially differentiated nephroblastoma: Histopathology (3).

Epithelial-lined cysts or unlined cyst-like structures.

Septa may contain nephroblastomatous epithelium.

No expansile solid component.

217

Cystic partially differentiated nephroblastoma: Variant.

Pediatric cystic nephroma contains no nephroblastomatous elements.

218

Cystic partially differentiated nephroblastoma vs. Cystic nephroblastoma.

The latter has an expansile solid component.

219

Mesoblastic nephroma: Epidemiology (2).

Patients are usually no more than 3 months old.

Most frequent congenital renal neoplasm.

220

Mesoblastic nephroma: Presentation.

Abdominal mass.

221

Mesoblastic nephroma: Behavior (2).

Excellent if completely resected.

222

Mesoblastic nephroma: Location.

Renal sinus.

223

Mesoblastic nephroma: Gross pathology (2).

Classic: Small; firm; resembles leiomyoma.

Cellular: Large; soft; cystic; focally hemorrhagic and necrotic.

224

Mesoblastic nephroma: Histopathology of classic type.

Resembles benign fibromatosis.

225

Mesoblastic nephroma: Histopathology of cellular type.

Sheets or vague fascicles of densely packed, plump, mitotically active cells.

Same as infantile fibrosarcoma.

226

Mesoblastic nephroma: Immunohistochemistry (2).

Positive: SMA, vimentin.

227

Mesoblastic nephroma: Electron microscopy.

Much endoplasmic reticulum.

228

Mesoblastic nephroma: Translocation.

t(12;15)(p13;q25).

229

Mesoblastic nephroma vs. cystic nephroma.

Mesoblastic nephroma: Spindle-cell mesenchymal tumor in infants.

Cystic nephroma: Bland cysts and ovarian-type stroma; occurs mainly in women.

230

Mesoblastic nephroma vs. metanephric adenoma.

Mesoblastic nephroma: Spindle-cell mesenchymal tumor in infants.

Metanephric adenoma: Small acini consisting of small, dark cells; occurs in adults.

231

Clear-cell sarcoma: Age group.

Between 6 months and 5 years.

232

Clear-cell sarcoma: Cytology of classic type (3).

Cytoplasm: Pale.

Nucleus: Vesicular.

Nucleolus: Inconspicuous.

233

Clear-cell sarcoma: Histopathology of classic type (2).

Cells form cords that are separated by regularly spaced fibrovascular arcades.

Normal renal structures are entrapped at the periphery of the tumor.

234

Clear-cell sarcoma: Variants (3).

Myxoid, sclerosing, epithelioid, many others.

235

Clear-cell sarcoma: Immunohistochemistry (2,3).

Positive: Vimentin, nerve-growth-factor receptor.

Negative: Cytokeratins, neural markers, WT1.

236

Clear-cell sarcoma: Prognosis.

Very aggressive.

237

Rhabdoid tumor: Age at presentation.

Usually less than 2 years.

238

Rhabdoid tumor:

A. Laboratory findings.
B. Associated tumor.

A. Hypercalcemia, hematuria.

B. PNET of the posterior fossa.

239

Rhabdoid tumor: Cytology.

Cytoplasm: Abundant, pink; often contains large eosinophilic globular inclusions.

Nucleus: Vesicular; thick membrane.

Nucleolus: Large.

240

Rhabdoid tumor: Immunohistochemistry (1,1).

Positive: Epithelial markers.

Negative: INI-1.

241

Rhabdoid tumor: Electron microscopy.

Intermediate filaments make up the cytoplasmic inclusions.

242

Rhabdoid tumor: Mutation.

Inactivation of INI-1 (hSNF5) on chromosome 22.

243

Rhabdoid tumor: Prognosis.

Bad enough in older children; dismal in infants.

244

Metastasis to the kidney: Leading primary sites (5).

Lung.

Melanoma.

Gastrointestinal tract.

Gonads.

Other kidney.

245

Metastasis to the kidney: Location.

Cortex or medulla (or both).

246

Diseases of podocytes: Laboratory finding.

Proteinuria.

247

Minimal-change disease: Epidemiology (2).

Most patients are young children.

Adults can be affected, particularly secondary to nephrotoxins.

248

Minimal-change disease: Histopathology.

Normal by H&E and by special stains.

249

Minimal-change disease: Electron microscopy (4).

Loss of foot processes.

Extensive microvillous transformation.

Generally normal glomerular basement membrane.

No deposits.

250

Focal-segmental glomerulosclerosis: Laboratory findings (2).

Nephrotic syndrome.

Azotemia.

251

Focal-segmental glomerulosclerosis: Etiologies (5).

Idiopathic.

Genetic.

Immunologic.

Drugs.

HIV.

252

Focal-segmental glomerulosclerosis: Electron microscopy (4).

Loss of foot processes.

Microvillous transformation.

Wrinkled glomerular basement membranes.

HIV-associated FSGS: Tubuloreticular inclusions may be seen.

253

Renal diseases of collagen: Affected parts of the nephron.

Glomerular basement membrane and/or mesangium.

254

Disorders of collagen, type IV (3).

Benign familial hematuria: Hematuria only; no progression.

Thin-basement-membrane disease: Hematuria; usually no progression.

Alport's syndrome: Hematuria and proteinuria.

255

Alport's syndrome: Additional manifestations (2).

X-linked type: Ocular abnormalities, sensorineural deafness.

256

Alport's syndrome: Electron-microscopic changes in the glomerular basement membrane (3).

Variations in thickness, sometimes with breaks.

"Basket-weave" alternation of dense and lucent areas.

Multilamellation and scalloping.

257

Alport's syndrome: Prognosis.

X-linked Alport's syndrome: End-stage renal disease in 90% of patients by age 40.

258

Alport's syndrome: Mutations (2).

Most cases of X-linked disease: COL4A5.

Some cases of AR or AD disease: COL4A3 or COL4A4.

259

Alport's syndrome: Histopathology of early lesion.

Normal.

260

Alport's syndrome: Histopathology of the glomerulus in a late lesion.

Irregular thickness of glomerular basement membrane.

Segmental solidification of the glomerular tuft (as in FSGS).

261

Alport's syndrome: Histopathology of the renal interstitium in a late lesion.

Fibrosis with tubular atrophy.

Foam cells.

Sclerosis and hyalinosis of arterioles.

262

Glomerular basement membrane: Normal thickness.

At least 200 nm.

263

Thrombotic microangiopathies: Components (2).

Endothelial injury.

Thrombosis.

264

Thrombotic microangiopathies: Examples (6).

Hemolytic-uremic syndrome.

TTP.

Malignant hypertension.

Renal crisis of scleroderma.

Antiphospholipid syndrome.

Iatrogenic thrombotic microangiopathy.

265

Thrombotic microangiopathies: Histopathology of acute glomerular disease (2).

Intracapillary thrombi.

Thickened walls of capillaries.

266

Thrombotic microangiopathies: Histopathology of chronic glomerular disease (2).

Membranoproliferative features with double contours ("tram-track" appearance).

Mesangial and global sclerosis.

267

Thrombotic microangiopathies: Histopathology of chronic interstitial disease (2).

Fibrosis.

Tubular atrophy.

268

Thrombotic microangiopathies: Histopathology of malignant hypertension (2).

"Onion-skin" appearance of blood vessels.

Extreme duplication of elastic lamina.

269

ANCA-mediated vasculitis of small vessels: Presentation (3).

Hematuria, proteinuria, rapid progression to renal failure.

Signs of systemic vasculitis.

Dermatological disease.

270

ANCA-mediated vasculitis of small vessels: Types of ANCA.

p-ANCA: Myeloperoxidase.

c-ANCA: Proteinase 3.

271

ANCA-mediated vasculitis of small vessels: Pathogenesis.

The ANCAs activate neutrophils, which injure the endothelium.

272

ANCA associated with

A. Wegener's granulomatosis.
B. Microscopic polyangiitis.
C. Churg-Strauss syndrome.
D. Renal-limited glomerulonephritis.

A. c-ANCA.

B,C,D. p-ANCA.

273

ANCA-mediated vasculitis of small vessels: Glomerular changes (2).

Cellular crescents progress to segmental glomerular scars.

Bowman's capsule may be occluded or disrupted.

274

ANCA-mediated vasculitis of small vessels:

A. Contents of cellular crescents (4).
B. Contents of glomerular scars.

A. Parietal epithelial cells, podocytes, inflammatory cells, fibrinoid necrotic débris.

B. More fibroblasts and fibrin.

275

ANCA-mediated vasculitis of small vessels: Extraglomerular vascular changes (2).

Leukocytoclastic vasculitis.

Transmural arteritis with fibrinoid necrosis.

276

ANCA-mediated vasculitis of small vessels: Other changes (3).

Interstitial inflammation.

Interstitial granulomas in Wegener's granulomatosis.

Acute tubular injury in aggressive forms.



277

Anti-glomerular-basement-membrane disease: Epidemiology (2).

Adolescent males.

Middle-aged females.

278

Anti-glomerular-basement-membrane disease: Presentation (2).

Acute renal failure with hematuria and proteinuria.

Pulmonary hemorrhage.

279

Anti-glomerular-basement-membrane disease: Pathogenesis.

Antibodies against the noncollagenous-1 domain of the α₃ chain of collagen, type IV.

280

Anti-glomerular-basement-membrane disease: Relevance to HLA type.

Strongly associated with HLA-DR and HLA-DQ.

281

Anti-glomerular-basement-membrane disease: Histopathology (4).

Cellular crescents involving all glomeruli.

Progression of crescents to segmental glomerular scars.

Interstitial inflammation.

Acute tubular injury in aggressive forms.

282

Anti-glomerular-basement-membrane disease: Serologic diagnosis (3).

DIF: Linear pattern of IgG on the GBM.

IIF: Anti-GBM antibodies in patient's serum react with normal kidney.

No ANCAs.

283

Immune-complex-mediated glomerular diseases: Types (3).

Membranous glomerulopathy.

Infection-mediated glomerular diseases.

IgA-mediated glomerular diseases.

284

Membranous glomerulopathy: Presentation.

Nephrotic syndrome progressing to ESRD in 30% of cases.

285

Membranous glomerulopathy: Etiologies (5).

Primary: Idiopathic, congenital.

Secondary: HCV, HBV, syphilis.

Autoimmune diseases.

GVHD.

Neoplasia.

286

Membranous glomerulopathy: Pathogenesis of idiopathic form.

Antibodies to phospholipase-A2 receptors in podocytes.

287

Membranous glomerulopathy: Histopathology (3).

Thickening of the GBM.

Mesangial expansion and proliferation.

Glomerulitis in cases associated with malignancy.

288

Membranous glomerulopathy: Special stain.

Silver stain: Spikes and/or gaps in the GBM.

289

Membranous glomerulopathy: Direct immunofluorescence (2).

GBM: IgG, C3, kappa, lambda in granular pattern.

Tubular basement membrane: Deposits seen in secondary forms.

290

Membranous glomerulopathy: Type of IgG (2).

Primary: Mainly IgG4.

Neoplastic: IgG1, IgG2.

291

Membranous glomerulopathy: Electron microscopy

Extensive effacement of foot processes.

Subepithelial electron-dense deposits.

Secondary forms: Deposits in mesangium, tubular basement membrane.

292

Infection-mediated glomerular disease: Laboratory findings (3).

Hematuria.

Proteinuria.

Hypocomplementemia.

293

Infection-mediated glomerular disease: Presentation.

Nephritic syndrome.

294

Infection-mediated glomerular disease: Etiologies (6).

Streptococci.

MRSA.

Viruses, rickettsiae, fungi, parasites.

295

Infection-mediated glomerular disease: Special stain.

Trichrome stain may show subepithelial humps.

296

Infection-mediated glomerular disease: Electron microscopy (2).

Subepithelial humps with effacement of overlying foot processes.

Subendothelial, intramembranous, and mesengial electron-dense deposits.

297

Infection-mediated glomerular disease: Direct immunofluorescence (2).

Granular pattern in basement membrane and mesangium

− Most cases: IgG and C3.
− MRSA-related: IgA and C3.

298

IgA-related nephropathies: Epidemiology.

Common in Asians; rare in blacks.

299

IgA-related nephropathies: Clinical presentations (2).

Asymptomatic: Occult hematuria and proteinuria.

Symptomatic: Nephritic syndrome.

300

IgA-related nephropathies:

A. Laboratory finding.
B. Prognosis.

A. Normal serum complement levels.

B. Recurs in 30% of transplants.

301

IgA-related nephropathies: Pathophysiology (2).

Abnormal glycosylation of IgA1.

Increased production of IgA.

302

IgA-related nephropathies: Relevance to HLA type.

Associated with HLA-DQ.

303

IgA-related nephropathies: Histopathology (2).

Variable; may resemble other glomerular diseases.

Diagnosis requires immunofluorescence.

304

IgA-related nephropathies: Direct immunofluorescence.

IgA, kappa, lambda, C3, generally in a mesangial pattern.

305

IgA-related nephropathies: Electron microscopy (3).

Mesangium: Deposits.

Basement membrane: Variable thinning; deposits in some cases.

Foot processes: Variable effacement.

306

IgA-related nephropathy vs. ANCA-associated vasculitis.

Significant mesangial proliferation favors an IgA-related nephropathy.

307

IgA-related nephropathy vs. FSGS.

Demonstration of mesangial deposits (by DIF or EM) favors an IgA-related nephropathy.

308

Membranoproliferative glomerulonephritis: Classification.

Types I and III: Mediated by immune complexes.

Type II: Mediated by complement; now known as dense-deposit disease.

309

Immune-complex-mediated membranoproliferative glomerulonephritis:

A. Epidemiology.
B. Presentation.

A. Children and young adults.

B. Both nephrotic syndrome and nephritic syndrome.

310

Immune-complex-mediated membranoproliferative glomerulonephritis:

A. Laboratory finding.
B. Etiologies (2).

A. Decreased serum complement.

B. HCV; idiopathic.

311

Immune-complex-mediated membranoproliferative glomerulonephritis, type I: Constant histopathologic feature.

Double contours formed by interposition of mesangial cytoplasm and deposits.

312

Immune-complex-mediated membranoproliferative glomerulonephritis, type III of Burkholder: Histopathology.

Features of MPGN I + mesangial proliferation and diffuse thickening of capillary walls.

313

Immune-complex-mediated membranoproliferative glomerulonephritis, type III of Anders and Strife: Histopathology (2).

Features of MPGN I + irregular thickening of capillary walls.

Less mesangial proliferation than in type III of Burkholder.

314

Immune-complex-mediated membranoproliferative glomerulonephritis, type III of Anders and Strife: Special stain.

Silver stain shows non-staining ("moth-eaten") areas of basement membrane.

315

Immune-complex-mediated membranoproliferative glomerulonephritis: Direct immunofluorescence.

"Lumpy-bumpy" deposits of IgG and C3 in mesangium and capillary walls.

316

Electron microscopy of immune-complex-mediated membranoproliferative glomerulonephritis:

A. Type I.
B. Type III of Burkholder.
C. Type III of Anders and Strife.

A. Double contours.

B. Double contours and numerous subepithelial deposits.

C. Double contours and deposits all throughout the basement membrane.

317

C3 glomerulopathies:

A. Age group.
B. Presentation.

A. Children and young adults.

B. Both nephrotic and nephritic syndromes.

318

C3 glomerulopathies: Pathogenesis.

Dysfunction of the alternative pathway of complement.

319

C3 glomerulopathies: Type (2).

C3 glomerulonephritis: Similar to MPGN I and III, but without immune complexes.

Dense-deposit disease.

320

C3 glomerulopathies: Histopathology (2).

C3 glomerulonephritis: Variable.

DDD: Irregular thickening of basement membrane; mild mesangial proliferation.

321

C3 glomerulopathies: Special stains (2).

Silver stain and PAS

− C3 glomerulonephritis: Double contours.
− DDD: "Moth-eaten" GBM.

322

C3 glomerulopathies: Direct immunofluorescence (2).

C3 glomerulonephritis: Granular deposition of C3.

DDD: "Garland" pattern of C3.

323

C3 glomerulopathies: Predictors of poor prognosis (3).

Older age at presentation.

Higher creatinine at presentation.

Extracapillary proliferation.

324

Lupus nephritis: Frequency (2).

Occurs in 80% of patients with lupus.

Presenting manifestation in 20% of lupus patients.

325

Lupus nephritis: Class I (2).

Normal glomeruli by histology.

Mesangial deposits by IF or EM.

326

Lupus nephritis: Class II (2).

Mesangial expansion and proliferation by histology.

Mesangial deposits by IF or EM.

327

Lupus nephritis: Class III (2).

Segmental or global focal endocapillary proliferation involving less than half of glomeruli.

Mesangial and subendothelial deposits by EM.

328

Lupus nephritis: Class IV (2).

Segmental or global diffuse endocapillary proliferation involving at least half of glomeruli.

Mesangial and subendothelial deposits by EM.

329

Lupus nephritis: Class V (2).

Thickened GBM by histology.

Subepithelial deposits by EM.

330

Lupus nephritis: Class VI.

Global sclerosis involving more than half of glomeruli.

331

Lupus nephritis: Definition of endocapillary proliferation (3).

Proliferation of mesangial and endothelial cells.

Inflammatory cells may be marginated.

Glomerulus appears lobulated and hypercellular.

332

Lupus nephritis: "Wire loops".

Large subendothelial deposits.

Best seen with trichrome stain.

333

Lupus nephritis: Definition of extracapillary proliferation.

Cellular crescents.

334

Lupus nephritis: Interstitial changes (2).

Acute: Plasmacytic inflammation and edema.

Chronic: Fibrosis and tubular atrophy.

335

Lupus nephritis: Vascular changes.

Variable.

336

Lupus nephritis: Silver stain (2).

Classes III and IV: Double contours.

Class V: Spikes and holes in the GBM.

337

Lupus nephritis: Direct immunofluorescence (2).

Granular distribution of all immunoglobulins and complement.

C1q is always present.

338

Electron microscopy of lupus nephritis:

A. Appearance of deposits.
B. Another abnormal structure.

A. May resemble fingerprints.

B. Tubuloreticular inclusions in endothelial cells.

339

Diabetic nephropathy: Early sign.

Microalbuminuria: Occurs more than 5 years before onset of diabetes.

340

Diabetic nephropathy: Stage 1 (2).

Light microscopy: Normal glomeruli.

Em: Thickened GBM.

341

Diabetic nephropathy: Stage 2 (2).

LM: Diffuse mesangial expansion.

EM: Thickened GBM; increased collagen in mesangium.

342

Diabetic nephropathy: Stage 3 (2).

LM: Diffuse nodular glomerulosclerosis (Kimmelstiel-Wilson lesion); abundant hyalinosis.

343

Diabetic nephropathy: Stage 4.

More than half of glomeruli are sclerotic.

344

Diabetic nephropathy: Types of hyaline lesion (3).

Fibrin caps (hyalinosis of capillaries).

Capsular drops.

Arteriolar hyalinosis.

345

Diabetic nephropathy: Interstitial changes (2).

Fibrosis and tubular atrophy.

346

Diabetic nephropathy: Vascular change.

Arteriolar hyalinosis involving afferent and efferent arterioles.

347

Diabetic nephropathy: Special stain.

Silver stain emphasizes sclerotic nodules.

348

Diabetic nephropathy: Direct immunofluorescence (2).

GBM, tubular BM: Linear IgG and albumin.

Areas of glomerular and vascular hyalinosis: C3 and IgM.

349

Electron microscopy of diabetic nephropathy:

A. Glomerular basement membrane.
B. Mesangium.

A. Diffuse and sometimes massive thickening.

B. Sclerosis; collagen fibrils.

350

Diabetic nephropathy vs. anti-GBM disease (2).

Diabetic nephropathy:

− Usually has no crescents.
− Linear deposition of albumin.

351

Fabry's disease: Affected organs (4).

Skin.

Nervous system.

Kidneys.

Gastrointestinal tract.

352

Fabry's disease:

A. Inheritance.
B. Gene and its product.
C. Pathogenesis.

A. X-linked.

B. AGAL; α-galactosidase A.

C. Accumulation of lipids in cells.

353

Fabry's disease:

A. Histopathology.
B. Special stain.

A. Lipid vacuoles in podocytes, tubular epithelial cells, and endothelial cells.

B. Toluidine blue reveals the inclusions.

354

Fabry's disease: Electron microscopy.

Lipids have lamellated appearance (zebra bodies).

355

Fabry's disease: Drug that can cause similar inclusions.

Chloroquine.

356

Renal amyloidosis: Presentation.

Nephrotic syndrome.

357

Renal amyloidosis: Immunoglobulin-derived amyloid (2).

AL, especially λ light chain.

Heavy chains.

358

Renal amyloidosis:

A. Most common genetic form.
B. Associated with chronic inflammation.
C. Associated with dialysis.

A. α-Fibrinogen.

B. AA (serum amyloid A).

C. β₂-microglobulin.

359

Renal amyloidosis: Other forms of amyloid (2).

Leukocyte chemotactic factor 2.

Transthyretin.

360

Renal amyloidosis: Histopathology (4).

Glomeruli: Thickening of basement membranes; mesangial nodules.

Tubules: Thickening of basement membranes.

Arterioles: Intimal nodules.

361

Renal amyloidosis: Electron microscopy.

Non-branching, randomly organized fibrils, 9-11 nm in diameter.

362

Renal amyloidosis vs. light-chain-deposition disease.

In the latter, there are finely granular, electron-dense deposits.

363

Acute tubular injury:

A. Presentation.
B. Laboratory finding.

A. Acute renal failure with oliguria or anuria.

B. Granular casts.

364

Acute tubular injury: Causes.

Ischemia (90%).

Nephrotoxins.

365

Acute tubular injury: Most vulnerable part of nephron.

The distal part.

366

Acute tubular injury: Histopathology (4).

Tubular epithelial cells:
− Loss of brush border.
− Necrosis in a minority of tubules.
− Regenerative changes.

Glomeruli and blood vessels: No change.

367

Acute tubular injury: Special stain.

PAS reveals loss of brush borders.

368

Drug-induced interstitial nephritis: Classic triad.

Hypersensitivity reaction.

Maculopapular rash.

Eosinophilia.

369

Drug-induced interstitial nephritis: Laboratory findings (3).

Mild proteinuria.

Microscopic hematuria.

Eosinophiluria.

370

Drug-induced interstitial nephritis: Causes (4).

NSAIDs.

Antimicrobials.

Diuretics.

Others.

372

Drug-induced interstitial nephritis: Electron microscopy.

NSAIDs: Diffuse injury to podocytes, with a effacement of foot processes.

373

Acute obstructive nephropathy: Causes (3).

Cast nephropathies:
− Myeloma.
− Myoglobin.
− Hemoglobin.

374

Myeloma cast nephropathy: Histopathology (3).

Fractured or crystalline-appearing casts surrounded by giant cells.

Reactive epithelial cells in the affected tubules.

Interstitial fibrosis and lymphocytic inflammation.

375

Myeloma cast nephropathy: Special stain.

Negative for PAS (Tamm-Horsfall casts are positive).

376

Hypertensive nephropathy: Other histologic changes (3).

Glomeruli: Global sclerosis.

Tubules: Atrophy.

Interstitium: Fibrosis.

377

Hypertensive nephropathy: Histologic changes in arteries (3).

Intimal fibrosis, medial hypertrophy, duplication of the elastic lamina.

378

Hypertensive nephropathy: Histologic change in arterioles.

Hyalinization.

379

Drug-induced interstitial nephritis: Histopathology (3).

Interstitial edema and inflammation, often including eosinophils.

Inflammation of tubules in the active phase.

Granulomas can be seen.