Renal Pathology V Flashcards
How common are congenital kidney abnormalities?
Common - 10%
What does the metanephric blastema become?
Nephrons
What does the ureteric bud become?
Collecting Duct System
Horseshoe Kidneys
Fused kidneys
Ectopic
Abnormal location
What is renal dysplasia?
NOT related to neoplasia but developmental abnormality.
Cystic Renal Dysplasia
Abnormality in metanephric differentiation - persistence of immature elements: undifferentiated mesenchyme, cartilage, immature collecting tubules, abnormal lobar organization
What do the gross kidneys look like in cystic renal dysplasia?
Grossly kidneys enlarged, irregular shape, “bunch
of grapes”
What other organ development can cystic renal dysplasia impact?
Lung - agenesis/bilateral dysplasia
What is the incidence of Childhood Autosomal Recessive Polycystic Kidney Disease?
Rare - 1 in 50000
What are the findings with Childhood Autosomal Recessive Polycystic Kidney Disease?
- Cross-section–sponge-like appearance
- Saccular dilatation of collecting tubules
- Liver: cysts+portal fibrosis+proliferation of portal bile ducts → congenital hepatic fibrosis
What are the findings with Adult Polycystic Kidney Disease (APKD)?
Bilateral, reniform shape, enlarged, mass of cysts, functioning nephrons dispersed between the cysts, hepatic cysts
What is the inheritance pattern of APKD?
Autosomal Dominant
Of the cystic diseases, which ones are bilateral?
ARPKD and APKD are bilateral
Dysplasia can be unilateral or bilateral
Of the cystic diseases, which ones have reniform shape?
ARPKD and APKD
Of the cystic diseases, which ones have ureter abnormalities?
Dysplasia
Of the cystic diseases, which ones have liver abnormalities?
ARPKD and APKD
What is the basic assumption of renal tumors?
Malignancy
What are the benign kidney tumors?
- Oncocytoma
* Angiomyolipoma
What is the origin of an oncocytoma?
Distal Nephron
What is the makeup of an angiomyolipoma?
Vessels/smooth muscle/fat
What is the triad of renal cell carcinoma presentation?
Costovertebral pain, mass, hematuria
What is the pathogenesis of a clear RCC?
von Hippel-Lindau, tumor suppressor gene is lost. Loss of VHL gene results in accumulation of the transcription factor HIF-1α (hypoxia inducible factor - 1α) and over-expression of HIF-1α target genes which facilitate cellular adaptation to tissue hypoxia
What is the control of HIF-1alpha by VHL?
Under normoxic conditions VHL ubiquitinates HIF-1a, leading to ubiquitin- mediated proteolysis and degradation by the proteasome
What is the function of HIF-1α in tumor cells?
In hypoxic cells, such as those found in tumors, HIF-1α ultimately initiates the transcription of hypoxia-induced genes, including those which promote
– cell survival under anaerobic conditions
– angiogenesis
– metastasis
What is the main treatment for RCC?
Surgery
What is mTOR?
mTOR is an intracellular serine/threonine kinase in the PI3K/Akt signaling pathway.
• mTOR activation promotes
– Cell growth and proliferation
– Angiogenesis
– Cancer cell metabolism through increased nutrient uptake and utilization
von Hippel-Lindau (VHL) Syndrome
- tumors with high vascularity + clear cells
- hemangioblastoma (central nervous system/cerebellum/spine)
- angiomas of the retina
- pheochromocytomas
What is the most common type of RCC?
Clear RCC
Papillary RCC
- better prognosis than clear cell RCC
- papillary architecture
- hereditary (familial) - multiple bilateral tumors with papillary histology
Chromophobe RCC
- Hypodiploidy - multiple chromosomal losses
- Distal nephron
- Prominent cell membrane “vegetable-like”
- Better prognosis in the absence of sarcomatoid component
Sarcomatoid RCC
- not a distinct type but rather indicative of de-differentiation
- worse prognosis, regardless of the original tumor morphology
Collecting Duct Carcinoma
- Collecting duct origin
- Chromosomal losses
- Very aggressive
Urothelial Carcinoma
- renal pelvis, ureter, frequently also concomitant urinary bladder tumor
- hematuria
- analgesic nephropathy = risk factor
Wilm’s Tumor Typical Patient
Most common pediatric kidney tumor
What is the treatment for Wilm’s tumor?
Chemotherapy. Prognosis is good as it is highly chemosensitive.
During a radiologic workup for gall bladder stones, a 65 yo male was found to have a 5 cm mass in his right kidney.
a. This is most likely oncocytoma
b. This is a benign tumor
c. Chemotherapy is effective
d. Surgery consultation should be scheduled
e. Tumor’s morphology shows abortive glomeruli/tubules and stroma
d. Surgery consultation should be scheduled
A 2 yo boy is brought to pediatrician because his mother palpated “a bulging mass” while bathing him. What best applies to the case?
a. This tumor most likely is composed of clear cells
b. This tumor typically shows loss of short arm of chromosome 3
c. This tumors is most likely highly chemoresistant
d. This tumor is chemosensitive
e. Tumor morphology will show immature tubules and cartilage
d. This tumor is chemosensitive
An infant is diagnosed with an enlarged left kidney – shown with “bunch of grapes” look. Most likely:
a. This lesion will respond to chemotherapy
b. This is a premalignant lesion
c. This is a congenital disorder and genetic testing is indicated
d. Kidney parenchyma shows persistence of immature elements
e. Kidney sections show blastema, tubules and stroma
d. Kidney parenchyma shows persistence of immature elements
