Lecture 4: Renovascular Disorders and Tumors

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Questions and Answers

What condition is primarily characterized by the effects of benign hypertension on the kidneys?

Benign nephrosclerosis (correct)

Malignant nephrosclerosis

Fibromuscular dysplasia

Renal artery stenosis

Which of the following is NOT a cause of renal artery stenosis?

Fibromuscular dysplasia

Vasculitis

Atherosclerosis

Malignant hypertension (correct)

What microscopic feature is characteristic of benign nephrosclerosis?

Necrosis of the renal tubules

Hypertrophy of the renal interstitium

Thinning and calcification of the renal cortex

Fibromuscular hyperplasia of large arteries (correct)

Which statement about malignant nephrosclerosis is true?

It can occur without preexisting hypertension. Signup and view all the answers

What gross feature is associated with benign nephrosclerosis?

Finely granular outer surface of both kidneys Signup and view all the answers

What is a characteristic microscopic feature of hyperplastic arteriolosclerosis?

Onion skin appearance Signup and view all the answers

What percentage of deaths in malignant hypertension is attributed to uremia?

90% Signup and view all the answers

Which type of renal tumor is associated with the von Hippel-Lindau disease?

Clear cell carcinoma Signup and view all the answers

What symptom is NOT typically associated with increased intracranial pressure?

Diarrhea Signup and view all the answers

What is the typical age range for the onset of renal cell carcinoma?

60-70 years Signup and view all the answers

Which risk factor is NOT commonly associated with renal cell carcinoma?

Hypertension Signup and view all the answers

What is the appearance of renal cell carcinoma on gross examination?

Well demarcated, solid, golden yellow Signup and view all the answers

Which type of benign kidney tumor is characterized by the presence of clear cells?

Oncocytoma Signup and view all the answers

What is a characteristic microscopic feature of papillary RCC?

Branching papillae covered by a single layer of cells Signup and view all the answers

Which clinical manifestation is common in late cases of renal cancer?

Flank pain and mass in the kidney region Signup and view all the answers

What type of renal cell carcinoma is typically characterized by large cells with granular eosinophilic cytoplasm?

Chromophobe RCC Signup and view all the answers

What is one of the paraneoplastic syndromes associated with renal cell carcinoma?

Polycythemia due to erythropoietic stimulating substance Signup and view all the answers

Which lymph nodes are primarily involved in the lymphatic spread of renal cancer?

Lumbar group of lymph nodes Signup and view all the answers

During which age range is Wilm's tumor most likely to occur?

Children aged 2-5 years Signup and view all the answers

What is a common initial local spread of renal tumors?

Infiltration of the renal capsule and perinephric fat Signup and view all the answers

Which histological component is NOT found in Wilm's tumor?

Acinar structures resembling pancreatic cells Signup and view all the answers

Study Notes

Lecture 4: RenoVascular Disorders and Renal Tumors

Renovascular disorders and renal tumors were discussed in the lecture.
The kidney has four main components: glomeruli, tubules, blood vessels, and interstitial tissue.
Learning Objectives (ILOs):
- Identify types of renovascular disorders their causes, pathogenesis, and clinical features.
- Classify kidney tumors, describe their pathologic features and complications.
Vascular diseases of the kidney:
- Renal artery stenosis: causes include atherosclerosis, fibromuscular dysplasia, and vasculitis. It leads to secondary hypertension.
- Benign nephrosclerosis: occurs due to benign hypertension, characterized by reduced kidney size, granular outer surface, and irregular cortex atrophy.
- Malignant nephrosclerosis: occurs due to malignant hypertension, characterized by petechial hemorrhages on the kidney surface (flea bitten kidney), fibrinoid necrosis, hyperplastic arteriolosclerosis (onion skin), and necrotizing glomerulitis.

Renal Artery Stenosis

Atherosclerosis, fibromuscular dysplasia, and vasculitis are causes.
Stenosis leads to increased renin, angiotensin II, vasoconstriction, and increased blood volume causing hypertension.
The adrenal cortex releases aldosterone.

Benign Nephrosclerosis

Abnormalities in the kidney induced by benign hypertension.
Both kidneys shrink.
The outer surface is granular.
The cut surface shows irregular atrophy of the cortex, loss of differentiation between cortex and medulla.
Microscopic findings:
- Large arteries: fibromuscular hyperplasia
- Arterioles: thickening and hyalinization of the walls; narrow lumens leading to diffuse ischemic atrophy of the nephrons.

Malignant Nephrosclerosis

May occur without preexisting hypertension or on top of it.
Gross: petechial hemorrhages on the cortical surface (flea bitten kidney).
Microscopic: fibrinoid necrosis, hyperplastic arteriolosclerosis (onion skin), and necrotizing glomerulitis

Clinical Course of Malignant Nephrosclerosis

Characterized by papilledema, encephalopathy, and renal failure.
Increased intracranial pressure leads to headache, nausea, vomiting, and visual impairment.
90% of deaths are caused by uremia and 10% by cerebral hemorrhage and cardiac failure.

Tumors of the Kidney

Tumors of the kidney are classified into benign and malignant groups in terms of primary and secondary tumors.
Benign tumors: adenoma, fibroma, lipoma, oncocytoma; papilloma, fibroma, and hemangioma in the pelvicalyceal system.
Malignant tumors: renal cell carcinoma, Wilm's tumor (primary); metastatic tumors from the lung, breast, prostate, and others (secondary) sarcoma (osteosarcoma), malignant melanoma, and choriocarcinoma

Renal Cell Carcinoma

Arises from epithelial cells of renal tubules.
Age: 60-70, male to female ratio: 2:1.
Risk factors: smoking, polycystic kidney on top of dialysis, genetic factors (von Hippel Lindau disease (AD) (VHL gene is TSG), Papillary RCC: MET protooncogene)
Gross: well demarcated, centered in cortex, solid, golden-yellow cut surface with areas of hemorrhage and necrosis.
Extension to the renal pelvis is early, and to the capsule is late.
Microscopic:
- Clear cell RCC: clear cells in solid masses, cords, tubules, or cysts, scanty stroma, high vascularity, hemorrhage, necrosis
- Papillary RCC: branching papillae covered by single layer of cells, large nuclei, small cytoplasm
- Chromophobe RCC: large cells, granular eosinophilic cytoplasm

Wilm's Tumor

Age: children (2-5 years)
Arises from embryonic cells.
Rapidly growing tumor infiltrating the renal capsule.
Infiltration of the renal pelvis and ureter is rare and late.
Microscopic:
- Blastematous areas (small, rounded cells, scanty cytoplasm).
- Mesenchymal elements (spindle cells, smooth muscle, cartilage differentiation).
- Epithelial component (anaplastic cells; glandular, tubular, glomerular formations).

Clinical Presentation

Large abdominal mass.
Hematuria.
Abdominal pain.
Intestinal obstruction.
Spread: Local (renal tissue, capsule, adrenal cortex, bowel, liver, vertebra), blood (lung, liver, brain), lymphatics (regional lymph nodes).

Clinical Manifestations

Painless hematuria.
Flank pain and mass in kidney area (late cases).
Manifestations from metastases to the lung and bones.
Anemia, fever, weight loss.
Paraneoplastic syndrome:
- Polycythemia (due to EPO-stimulating substance)
- Hypercalcemia (due to PTH-like hormone)
- Gynecomastia (due to gonadotropin and placental lactogen production).

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Description

This quiz covers the key concepts from Lecture 4 on renovascular disorders and renal tumors. You will learn about the causes, pathogenesis, and clinical features of various kidney diseases, as well as the classification and pathology of kidney tumors. Test your understanding of these critical topics in nephrology.