Neoplasms of the kidney

Neoplasms of the kidney proper Neoplasms of the renal pelvis & ureter

Neoplasms of the kidney proper Benign: adenoma, haemangioma, fibroma, lipoma Malignant: adenocarcinoma, nephroblastoma, sarcoma Benign neoplasm of the kidney is very rare hence all neoplasms should be regarded as malignant

KEY POINTS: BENIGN RENAL TUMORS Tumor TypeDistinctive Features Benign renal cystTypically asymptomatic Water density and homogeneous Renal cortical adenomaCommonly found at autopsy Difficult to differentiate from RCC—controversial More commonly found with papillary RCC and in end-stage renal failure Working definition: small (<1 cm), well circumscribed, low grade, and papillary Metanephric adenomaIncidental presentation, peak incidence is fifth decade May be related to Wilms' tumor or papillary RCC Cannot be differentiated from RCC by clinical or radiographic means OncocytomaTypically tan and homogeneous in gross appearance Eosinophilic with nested or organoid appearance Multiple mitochondria on electron microscopy Common loss of chromosomes 1 and Y; alterations of 14q and 11q13 Cannot be differentiated from RCC by clinical or radiographic means AngiomyolipomaSporadic or associated with tuberous sclerosis syndrome Fat density found with CT; hyperechoic on ultrasonography Typically intervene if symptomatic or large (>4 cm) Options for management: selective embolization, partial nephrectomy Cystic nephromaMiddle-aged women or young males Radiographically presents as Bosniak III-IV cyst Herniation into collecting system can be clinical clue Difficult to differentiate from cystic malignancy Partial nephrectomy if diagnosis suspected

Renal cell carcinoma ❏ eighth most common malignancy (accounts for 3% of all newly diagnosed cancers) ❏ 85% of primary malignant tumours in kidney ❏ male: female = 3:1 peak incidence at years of age ❏ called the “internist’s tumour” because of paraneoplastic symptomatology

Renal cell carcinoma Alternative names include: – Hypernephroma - initially believed to arise from adrenal gland – Clear cell carcinoma - histologically have small nuclei and abundant cytoplasm – Grawitz tumour Increased incidence seen in von Hippel-Lindau syndrome Pathologically may extend into renal vein and inferior vena cava Blood born spread can result in 'cannon ball' pulmonary metastases

Renal cell carcinoma: etiology cause is unknown originates from proximal convoluted tubule epithelial cell histologically divided: clear, granular, and spindle cell types risk factors: smoking (results in 2x increased relative risk), cadmium exposure, employment in leather industry familial incidence seen with von Hippel Lindau syndrome which is characterized by RCC (present in 2/3), usually bilaterally headache, ataxia, and blindness due to cystic lesions of cerebellum, retinal vessel aneurysms, and tumours or cysts of the pancreas

Clinical features increasingly diagnosed incidentally with U/S and CT poor prognostic indicators: weight loss, weakness, anemia, bone pain classic triad (too late triad!) found in 10-15% gross hematuria 50% flank pain < 50% palpable mass < 30% 30% have metastases when first seen paraneoplastic syndromes (10-40% of patients) hematopoietic disturbances: anemia, polycythemia; raised ESR endocrinopathies: hypercalcemia, production of other hormones including erythropoietin, renin, prolactin, gonadotropins, TSH, insulin, and cortisol hemodynamic alterations: systolic hypertension (due to AV shunting), peripheral edema (due to caval obstruction) “Staufer’s syndrome”: abnormal liver function tests, decreased WBC count, fever, areas of hepatic necrosis; reversible following removal of primary tumour

❏ methods of spread: direct, venous, lymphatic

Staging of tumour Stage 1 - Confined to the kidney Stage 2 - Involvement of perinephric fat but Gerota's fascia intact Stage 3 - Spread into renal vein Stage 4 - Spread into adjacent or distant organs Prognosis depends on pathological stage, tumour size, nuclear grade and histological type

❏ diagnosis routine labs for paraneoplastic syndromes (CBC, ESR) urinalysis (60-75% have hematuria) IVP renal ultrasound CT scan angiography: no longer routinely done

Clues-- When a renal mass is identified on intravenous pyelography, features suggestive of malignancy include calcification within the mass, increased tissue density, irregularity of the margin, and distortion of the collecting system USG A renal mass that is not clearly a simple cyst by strict ultrasound criteria should be evaluated further with computed tomography (CT) scanning The primary indications for needle aspiration or biopsy of a renal mass are when a renal abscess or infected cyst is suspected and when RCC must be differentiated from metastatic malignant disease or renal lymphoma

❏ treatment surgical (mainstay) radical nephrectomy en bloc removal of kidney, tumour, ipsilateral adrenal gland and intact Gerota’s capsule and paraaortic lymphadenectomy surgical removal of solitary metastasis may be considered radiation for palliation for painful bony lesions chemotherapy: NOT effective immunotherapy: investigational

Prognosis stage at diagnosis is the single most important predictor of survival 5 year survival of T1 is % 5 year survival of T2-T3 is approximately 60% 5 year survival of patients presenting with metastasis is 0-20%