Renal Cell Carcinoma: Diagnostic Work-Up
Basic Investigations for Renal Tumor:
The following studies are always indicated for a suspected renal tumor (Riccabona et al, 2003):
- laboratory tests
- ultrasound imaging of kidney and liver
- abdominal CT with contrast media, alternatively MRT of the kidneys
- chest x-ray
- urine sediment
- complete blood count
- liver enzymes
- AP, LDH
- blood clotting tests
Renal cell cancer usually presents as a hypoechoic or isoechoic tumor of the kidney. The tumor may be located in the renal sinus or exophytic in the perirenal tissue [fig. ultrasound imaging of renal cell carcinoma]. Lesions of the kidney suspicious for renal cell cancer are further investigated with abdominal computed tomography (with contrast media) or alternatively with MRI of the kidney.
The liver should be examined for liver metastases. In advanced tumors, Doppler ultrasound imaging may reveal a thombus in the renal vein or vena cava inferior.
Ultrasound imaging of a large renal cell carcinoma
Abdominal Computed Tomography:
Abdominal computed tomography is the diagnostic procedure of choice for the diagnosis of renal cell carcinoma if a renal tumor is present [fig. renal cell carcinoma in CT and large RCC with vena cava thrombus]. Abdominal CT provides sufficient information for the dignity of the renal tumor, preoperative staging, presence of vein thrombus, renal function of the contralateral kidney and if lymphadenopathy is present. Lymph nodes of more than 1 cm in diameter are suspicious for lymph node metastasis.
Abdominal CT of a pT3a renal cell carcinoma: horizontal plane (left image) and frontal plane (right image): left-sided advanced renal cell carcinoma with infiltration into the renal vein. With kind permission of Dr. G. Antes, Kempten.
MRI is indicated for patients with suspected renal tumor and if renal failure or contraindications for contrast media are present. MRI may be also useful for doubtful findings in computed tomography or for exact diagnosis of the cranial extension of a vena cava thrombus.
Chest X-Ray or CT-Thorax:
A chest radiograph is the minimal standard for detecting lung metastases. A CT-Thorax is mandatory for patients with pathological findings in chest x-ray. CT-Thorax is also useful as a primary diagnostic tool in advanced renal cell carcinoma of for patients with pulmonary complaints.
Investigations Reserved for Special Situations:
Venography or transesophageal ultrasound:
Indicated just before surgical treatment of a renal cell carcinoma with thrombus in the vena cava to detect the exact cranial extension of the thrombus.
A bone scan is indicated in advanced renal cell carcinoma with elevated AP, with bone pain or metastases in other locations.
Positron emission tomography:
PET has not demonstrated any benefit in the diagnosis of renal cell carcinoma. Current guidelines do not recommend PET for imaging, even for advanced tumors.
Fine needle biopsy:
Biopsy of renal masses is indicated if abscess, lymphoma or metastasis are suspected or if a histological confirmation of an advanced tumor is needed for targeted therapy. False negative histology may occur in 5–15%. Complications of the biopsy are bleeding, infection, arteriovenous fistula or pneumothorax. Serious complications or tumor contamination of the needle tract are rare.
Prevention (early detection) of renal cell carcinoma
Due to the low incidence of renal cell carcinoma and the high prevalence of harmless benign renal tumors, regular screening of the general population is not recommended. Screening should be offered to the following risk groups: patients with end-stage renal disease, tuberous sclerosis, Hippel-Lindau disease or cystic kidney disease.
Differential Diagnosis of a Renal Mass
The compilation is modified from [Campbell 2007].
Inflammatory renal tumors:
Abscess, xanthogranulomatous pyelonephritis, infected renal cyst, tuberculosis, rheumatic diseases with granulomas
Renal tumors of mature renal parenchyma:
Adenoma, renal cell carcinoma
Renal tumors of immature renal parenchyma:
Wilms tumor, sarcoma
Renal tumors of the renal pelvis:
Papillomas, transitional cell carcinoma, squamous cell carcinoma, adenocarcinoma
Cystic renal tumors:
Simple or complex renal cyst, parapelvic renal cysts, benign multilocular renal cyst, caliceal diverticula, cystic nephroma, polycystic kidney disease, non Hippel-Lindau disease, tuberous sclerosis, lymph cysts.
renal tumors of the vascular system:
Hemangioma, hamartoma, lymphangioma, angiomyolipoma
Renal tumors of the nervous system:
Neuroblastoma, sympathicoblastoma, schwannoma.
Mesenchymal renal tumors:
Fibroma, fibrosarcoma, lipoma, liposarcoma, leiomyoma, leiomyosarcoma
Perirenal renal tumors:
Retroperitoneal sarcoma and other mesenchymal tumors, teratoma, neuroblastoma, lymphoma, lymph node metastases of e.g. testicular tumors.
Lung cancer, breast cancer, gastrointestinal cancers, malignant melanoma, lymphoma.
Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
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