Kidney Congenital Abnormalities, Cystic Lesions, Kidney Tumors Flashcards
List the 3 main stages of kidney development in utero
Pronephros
Mesonephros
Metanephros
When does the pronephros appear? Where does it appear?
Pronephros forms around the 4th week
Moves from cervical region to caudal
What structures join to form the ureteric bud?
Mesonephric duct and the cloaca
What % of people are born with potentially significant malformations of the kidneys?
10%
What is a horseshoe kidney?
Fused kidneys with a common pole under the inferior mesenteric artery
Pt has one fused kidney instead of two
What is renal dysplasia?
Abnormal development of the kidney/nephrons
NOT related to neoplasia
What is the primary pathological issue in Cystic Renal Dysplasia?
Abnormality in metanephric differentiation
Presence of immature elements like mesenchyme and cartilage
What is the common gross appearance of Cystic Renal Dysplasia?
“Bunch of grapes”
See cysts and cartilage present outside of the kidney
What is the inheritance of Childhood Autosomal Recessive Polycystic Kidney Disease (ARPKD)?
Autosomal recessive, so very rare
What is the pathology associated with ARPKD?
Enlarged kidneys, but they retain a normal shape
Saccular dilations of the renal tubules
What are the primary symptoms of Adult Polycystic Kidney Disease (APKD)?
May be asymptomatic Pain Colic Mass Hemorrhage
What is the inheritance pattern of APKD?
Autosomal dominant
Describe the pathology of APKD
Huge kidney size (normal shape)
Many cysts present in the kidney and liver
May also see intracranial berry aneurysms
APKD
Treatment
Kidney transplant
Perhaps liver transplant too depending on function
APKD
Prognosis
Renal failure in middle age/later life depending on the mutation present
Acquired Cystic Disease
Where are the cysts seen?
Both the renal cortex and medulla
Acquired Cystic Disease
What should you do follow-up tests for?
Detection of cancer
Simple Cysts
Symptoms
Often asymptomatic
Simple Cysts
Why would one need to be removed?
Removed for fear of renal cancer
What is the general rule of thumb with all kidney tumors? (They are all presumed to be…)
All kidney tumors are presumed to be malignant until proven otherwise
List the two benign kidney tumors
Oncocytoma
Angiomyolipoma
Oncocytoma
What is it? What does it look like radiologically?
Benign tumor of the kidney, but looks like renal cell carcinoma by imaging
Oncocytoma
How are they usually treated?
They are benign, but they are commonly removed for fear of malignancy
Angiomyolipoma
What is this tumor made of? How can it be diagnosed?
Vessels, smooth muscle, and fat
May be diagnosed radiologically due to high fat density
Angiomyolipoma
What complication are you worried about?
Worried about potential for rupture from large vessels present with abnormal walls
You would remove the angiomyolipoma to lower this risk
Renal Cell Carcinoma
Triad of symptoms
Costovertebral pain
Mass
Hematuria
(Could also present with fever, malaise, weakness, weight loss, polycythemia, hypercalcemia, HTN)
Where is Renal Cell Carcinoma most likely to metastasize?
Lungs and Bones
Clear Cell RCC
Where is the mutation?
Mutation on chromosome 3 leading to inactivation of the VHL gene (a tumor suppressor)
Clear Cell RCC
What does the mutation lead to an accumulation of?
Accumulation of transcription factor HIF-1a and an overexpression of its target genes
Facilitates cellular adaptation to tissue hypoxia
Where does Clear Cell RCC commonly originate from?
Proximal tubular epithelium
Describe the gross appearance of Clear Cell RCC
“Hypernephroma” due to similarity in appearance to adrenal gland
Clear Cell RCC
Prognosis
Stage dependent
Clear Cell RCC
Treatment
Surgical removal
RCC is very chemoresistant, so surgery is usually the best option
VHL Syndrome
Pathogenesis
Multiple bilateral cysts and tumors with high vascularity and clear cells
Papillary RCC
Describe the pathogenesis. How is it acquired?
Hereditary
See multiple bilateral tumors with papillary histology
Papillary RCC
Prognosis
Better prognosis than Clear Cell RCC
What is the most common pediatric renal cancer?
Wilm’s Tumor
What is the mutation leading to Wilm’s tumor?
Loss of function mutations in WT1 and WT2
Wilm’s tumor is a triphaic tumor. What are the three pathological characteristics?
Malignant blastema (small undifferentiated blue cells)
Tubules
Stroma
What are treatment options for Wilm’s Tumor? How should you approach this treatment?
They are very soft tumors and it is crucial to correctly stage the tumor.
If there is extrarenal extension of the tumor, the child will need chemotherapy following removal of the tumor. If the tumor was limited to the kidneys, they will not need chemo.
Wilm’s Tumor
Prognosis
Excellent - 90% survival at 5 years
