RENAL TUMORS

Classification

Benign

• Cortical adenoma
• Angiomyolipoma

Malignant

• RCC
• Upper tract TCC
• Nephroblastoma
• Squamous CA of renal pelvis

Cortical adenoma

• Discovered incidentally, mostly found on autopsy
• Less than 1 cm without malignant features (pea like)
• Symptoms are unusual

Microscopically uniform basophilic or acidophilic with monotonous nuclear and cellular composition

Renal angiomyolipoma

• May occur alone or a part of tuberous sclerosis
• Hamartomas composed of fat, smooth muscle, and blood vessels
• AML may be found in the eyes, heart, lung and bone

• Malignant Tumors

Wilms tumor (nephroblastoma)

 Peak age:2-5 years

Risk factors

. WAGR syndrome-Wilms tumor, aniridia, genital anomalies, and mental retardation

. Beckwith-Wiedemann syndrome

.Tumor suppressor genes

 . WT-l (llp13)

 . WT-2 (llp15)

Gross: large solitary tan mass

Micro

1. Metanephric blastema

ii. Epithelial elements (immature glomeruli and tubules)

iii. Stroma

C/F:

Abdominal mass

Pyrexia

Hematuria

Metastasis occurs early, mainly to lungs.

Inv:

USG

Urography or

CT

Treatment: 

Nephrectomy followed by radiation with or without chemotherapy

If B/L tumor: Partial Nephrectomy

Prognosis: excellent; long-term survival rate of 90%

Renal Cell carcinoma

Epidemiology

- Male: Female  2:1

- 40-60 years of age

Risk factors

i. Cigarette smoking

ii. Chronic analgesic use

iii. Asbestos exposure

iv. Chronic renal failure and acquired cystic disease

v. Von Hippel- Lindau disease

Gross

. Large solitary yellow mass found in the poles (most commonly in the upper pole: most common site- PCT)

. Areas of necrosis and hemorrhage are commonly present

. The tumor often invades the renal vein and may extend into the vena cava and heart

Pathology

Clear cell types

• more than 80%
• polygonal or round cells with clear cytoplasm

Papillary variant

• 14% of RCC
• macroscopic feature-small, confined to cortex and nearly completely encapsulated
• Micro: papillae covered by small cells with scanty cytoplasm, arranged in a single layer on the papillary basement membrane with low nuclear grade

Sarcomatoid

• aggressive behavior and poor prognosis
• microscopic features- spindle cell pattern

Chromophobe variant

• 4% of RCC
• microscopic features light and transparent cytoplasm
• better prognosis

Signs and symptoms

Classic triad (pain, lump and hematuria) is found only in 10% cases

Weight loss, fever, hematuria, night sweats and sudden development of varicocele

Paraneoplastic syndromes from ectopic hormone production

   . Polycythemia(erythropoietin production)

   . Hypertension (renin production)

   . Cushing syndrome (corticosteroid synthesis)

   . Hypercalcemia (PTH-like hormone)

   . Feminization or masculinization (gonadotropin release)

High incidence of metastasis on initial presentation

May cause amyloidosis, a leukemoid reaction, or eosinophilia

Investigations

IVU

CT scan

• Renal Angiogram
• CX-Ray
• Bone scan

Treatment

• RCC is highly resistant to radio and chemotherapy
• Nephrectomy with removal of the perinephric fat