PATH exam

Question 1

Name a systemic disease in which you may see MPGN-type renal disease.

Answer 1

It can occur in association with SLE, hepatitis B or C antigenemia, and alpha1-antitrypsin deficiency.

Question 2

What are predisposing factors for developing necrotizing papillitis?

Answer 2

Compromised blood supply (eg, diabetes mellitus, sickle cell anemia), acute pyelonephritis with obstruction, nephritis associated with analgesic abuse.

Question 3

What is the survival rate for Wilms tumor?

Answer 3

The survival rate for Wilms tumor is 90% with treatment combining chemotherapy, radiation, and surgery.

Question 4

What is the Whipple triad?

Answer 4

1) Symptoms of hypoglycemia are present, especially confusion, stupor, or loss of consciousness. 2) Hypoglycemia is present, typically glucose less than 50 mg/dL. 3) Attacks are precipitated by fasting or exercise and are promptly relieved by administration of glucose.

Question 5

Are WBC casts seen only in acute pyelonephritis?

Answer 5

The presence of WBC (neutrophils) in casts indicates that acute tubular inflammation of the kidney is present. Thus, they may also be seen in acute tubulointerstitial nephritis and acute tubular necrosis.

Question 6

What would the IF show in this segmentally sclerotic focus (focus segmental glomerulosclerosis)?

Answer 6

IF will be positive in the sclerotic focus, which will stain with antibodies to IgM and C3.

Question 7

Why do medullary carcinomas not arise within the thyroid isthmus or thyroglossal duct remnants?

Answer 7

C cells migrate separately from follicular cells embryologically. C cells migrate from the neural crest to the lateral thyroid lobes; follicular cells migrate from the midline tongue base down the anterior neck.

Question 8

Compare and contrast clinical features of goiter with those of thyroid neoplasms.

Answer 8

Goiters generally have multiple nodules. Peak occurrence is during menstruating years of women, and patients are usually euthyroid. Thyroid neoplasms generally are solitary masses. They occur in patients over a wider age range than do goiters; patients are also usually euthyroid (although the nodule itself may be cold). Fixation to adjacent structures and hoarseness due to invasion of the recurrent laryngeal nerve are findings of advanced carcinoma.

Question 9

Is FSGS the result of immune complex injury?

Answer 9

No. The basic lesion in primary FSGS is disruption of visceral epithelial cells by unknown mechanisms. The sclerosis and entrapment of plasma protein, including IgM and C3, are nonspecific. They result from hyperpermeability at sites of epithelial cell damage.

Question 10

What does the abrupt enlargement of the thyroid nodule indicate?

Answer 10

Abrupt enlargement of a thyroid nodule usually indicates hemorrhage into a pre-existing goiter nodule, though hemorrhage into a neoplasm can also occur spontaneously. Most thyroid neoplasms are slow-growing, but the uncommon anaplastic carcinoma grows visibly in the course of weeks.

Question 11

What do you expect to see on electron microscopy (EM) of IgA nephropathy?

Answer 11

The EM will show mesangial deposits.

Question 12

What is the pathogenesis of necrotizing papillitis?

Answer 12

This complication requires the presence of three factors: (1) acute pyelonephritis (2) obstruction to urine flow, as with a stone or neurogenic bladder in diabetes (3) compromised blood supply, as with diabetes or sickle cell anemia. It results from a combination of ischemia and infection. Ischemia in diabetes results from microangiopathy, and diabetics are also more prone to infections.

Question 13

What are the opposites of diffuse and global with respect to renal pathology?

Answer 13

Diffuse is the opposite of focal. Global is the opposite of segmental.

Question 14

In what area are the deposits located, in membranous glomerulopathy?

Answer 14

The deposits are located in the outer aspect of the glomerular basement membrane (GBM) under the visceral epithelium of the Bowman capsule. Thus, they are subepithelial.

Question 15

Compare and contrast primary and secondary parathyroid hyperplasia.

Answer 15

Histologically similar, but clinically quite different. Primary - autonomous high PTH causes hypercalcemia; treated surgically (excise 3 1/2 glands). Secondary - hypocalcemia (most often due to renal failure) stimulates parathyroid hyperplasia; treated by calcium supplementation (or renal transplantation).

Question 16

What are other causes of asymptomatic hematuria?

Answer 16

Alport syndrome and thin glomerular basement membrane (GBM) disease are also associated with asymptomatic hematuria.

Question 17

How do you confirm that this patient has IgA GN?

Answer 17

You confirm the diagnosis by IF staining with anti-IgA.

Question 18

What is the pathogenesis of acute pyelonephritis?

Answer 18

Acute pyelonephritis is caused most commonly by enteric gram-negative rods that reach the kidney by ascending infection. This type of infection is favored by instrumentation (eg catheters) and by obstruction in the lower urinary tract (eg, prostate enlargement). Incompetence of the vesicoureteral valve is also important, because reflux of urine from the bladder allows the infection to move upward to the kidney.

Question 19

What is the classic triad of presenting symptoms of renal cell carcinoma?

Answer 19

The classic triad of presenting symptoms is: (1) Costovertebral angle pain (2) Palpable mass (3) Hematuria. However, these are seen together in only 10% of patients. Most reliable is hematuria, seen in 90%.

Question 20

Are the spikes part of the deposits?

Answer 20

No. The spikes are part of the GBM that lies between the deposits.

Question 21

What is the biochemical stimulant to hyperplasia in goiter?

Answer 21

Goiters usually form when some derangement that hampers thyroid hormone output causes compensatory elevation of the TSH level. The TSH causes hyperplasia and hypertrophy of thyroid epithelium.

Question 22

What other lab test can narrow the diagnosis in crescentic GN (aside from IF)?

Answer 22

Antineutrophil cytoplasmic antibody (ANCA). ANCA is negative in type I and type II crescentic GN, and it is positive in type III.

Question 23

What characteristics are seen in late stages of FSGS?

Answer 23

dense glomerular sclerosis and more interstitial fibrosis, tubular atrophy, and chronic inflammation

Question 24

What are the complications of stones?

Answer 24

Stones in the ureter may cause intense pain (renal colic); they may cause hematuria, and, most importantly, they predispose to urinary tract infection.

Question 25

What are the clinical differences between IgA nephropathy and Henoch-Schonlein purpura?

Answer 25

While these two conditions have similar histologic changes in the kidney, Henoch-Schonlein purpura is a systemic disorder involving skin (purpura), gastrointestinal tract (abdominal pain, intestinal bleeding), and joints (arthritis).

Question 26

What are the common causes of hypoadrenalism?

Answer 26

Autoimmune lymphocytic adrenalitis, granulomatous infections of the adrenal glands, anterior pituitary failure. Metastases to the adrenal glands usually do not affect adrenal function.

Question 27

What is another name for MPGN?

Answer 27

Mesangiocapillary GN.

Question 28

What are the histologic features of malignant hypertension?

Answer 28

Fibrinoid necrosis of small and medium-size arteries and hyperplastic arteriolosclerosis.

Question 29

What is proliferating in MPGN?

Answer 29

Mesangial cells, monocytes, and lymphocytes.

Question 30

What would the immunofluorescence (IF) pattern look like in membranous glomerulopathy?

Answer 30

The IF pattern would be granular and peripheral, which correlates with the immune complex deposits between the spikes.

Question 31

How would a radioactive iodine scan look in a thyroid gland such as the one pictured here (multinodular goiter)?

Answer 31

Heterogeneous uptake, patchy warm and cold nodules.

Question 32

What is the pathogenesis of chronic pyelonephritis?

Answer 32

Recurrent inflammation and scarring because of obstruction or reflux.

Question 33

How does this appearance (renal cell carcinoma) compare with that of Wilms tumor (Image 6)?

Answer 33

Wilms tumor has blue cells with sparse cytoplasm. Renal cell carcinoma has clear cells and abundant cytoplasm.

Question 34

How do the follicular cells in an adenoma compare with normal thyroid parenchyma?

Answer 34

Follicular cells in adenomas tend to have larger nuclei and a slightly higher N:C ratio than non-neoplastic thyroid tissue.

Question 35

The craniopharyngioma is thought to be derived from vestigial remnants of __________.

Answer 35

Rathke’s pouch.

Question 36

What are the types of MPGN?

Answer 36

There are two types of primary MPGN. Type I, the more common form, is an immune-complex disease and shows a granular pattern of IgG and C3 deposition by IF. The immune complexes are subendothelial by EM. Type II, the less common form, has C3 but not IgG in a granular-linear pattern on the basement membrane and as aggregates in the mesangium. The two are distinguished best by electron microscopy.

Question 37

What cell causes the split (tram-track) membrane?

Answer 37

Extension of the mesangial cells.

Question 38

What paraneoplastic syndromes are associated with renal cell carcinoma?

Answer 38

It may cause polycythemia, hypercalcemia, Cushing syndrome, and amyloidosis.

Question 39

What are the clinical features of IgA nephropathy?

Answer 39

IgA nephropathy is a disease of children or young adults, who present with hematuria within a day or two of an episode of respiratory, urinary, or gastrointestinal infection. The hematuria usually subsides, but it recurs within weeks to months. IgA nephropathy is an important cause of recurrent hematuria. Mild proteinuria may be present. This slowly progressive disease results in renal failure in as many as half of the cases. It is thought that IgA synthesis is increased in response to mucosal infections. The IgA forms immune complexes that deposit in the mesangium.

Question 40

What genetic abnormalities and malformation syndromes are associated with Wilms tumor?

Answer 40

Wilms tumors are associated with deletion of WT1 (WAGR and Denys-Drash syndromes) or WT2 (Beckwith-Wiedemann syndrome) loci on chromosome 11.

Question 41

How does scarring in this case (chronic pyelonephritis) differ from that seen in chronic glomerulonephritis or longstanding benign hypertension?

Answer 41

The scars of pyelonephritis are wide and irregular and affect the two kidneys unequally; by comparison, scars of chronic glomerulonephritis and hypertension result from diffuse small-vessel narrowing, and, hence, they are fine, uniform, and bilaterally symmetric.