Renal Cell Carcinoma Workup

Updated: Apr 03, 2017
  • Author: Kush Sachdeva, MD; Chief Editor: E Jason Abel, MD  more...
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Workup

Approach Considerations

With the increasing utilization of imaging studies, renal cell carcinoma (RCC) is increasingly detected incidentally, as a suspicious mass on abdominal computed tomography (CT) or ultrasound. [19] Fewer patients present with symptomatic disease (eg, gross hematuria, flank mass or pain).

RCC is remarkable for the frequent occurrence of paraneoplastic syndromes, including hypercalcemia, erythrocytosis, and nonmetastatic hepatic dysfunction (ie, Stauffer syndrome). Thus, laboratory studies in the evaluation of RCC should include a workup for paraneoplastic syndromes.

A number of imaging modalities are used to evaluate and stage suspected renal cancer, including the following:

  • CT of the abdomen, preferably with pelvic CT
  • Magnetic resonance imaging (MRI), if venous involvement is suspected or the patient cannot tolerate contrast
  • Ultrasonography
  • Chest CT scan or chest x-ray
  • Excretory urography
  • Renal arteriography
  • Venography
  • Bone scan if bone metastasis is suspected or alkaline phosphatase level is elevated
  • Brain CT or MRI if patient has clinical manifestations suggesting brain metastases

Determining whether a space-occupying renal mass is benign or malignant can be difficult. Imaging studies should be tailored to enable further characterization of renal masses, so that nonmalignant tumors can be differentiated from malignant ones.

Contrast-enhanced CT scanning has become the imaging procedure of choice for diagnosis and staging of renal cell cancer and has virtually replaced excretory urography and renal ultrasonography. Ultrasonographic examination can be useful in evaluating questionable cystic renal lesions if CT imaging is inconclusive. Large papillary renal tumors are frequently undetectable by renal ultrasonography.

Excretory urography is not used frequently in the initial evaluation of renal masses because of its low sensitivity and specificity. A small- to medium-sized tumor may be missed by excretory urography.

Renal arteriography is not used in the evaluation of a suspected renal mass as frequently now as it was in the past. When inferior vena cava involvement is suspected, either inferior venacavography or magnetic resonance angiography (MRA) is used. MRA is currently the preferred imaging technique. Knowledge of inferior vena cava involvement is important in planning the vascular aspect of the operative procedure.

Positron emission tomography (PET) imaging remains controversial in kidney cancer. Currently, PET is not considered a standard part of the diagnosis of kidney cancer or in follow-up for evidence of relapse after nephrectomy. [20] PET has a better sensitivity for detecting metastatic lesions than for determining the presence of cancer in the renal primary site.

When clinically indicated, bone scans are used both in inital workup and follow-up. A bone scan is recommended for patients with pain or an elevated alkaline phosphatase level. [20]

For more information, see Renal Cell Carcinoma Imaging.

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Initial Laboratory Studies

The following are initial laboratory studies in the evaluation of suspected renal cell carcinoma (RCC):

  • Urinalysis (UA) with urine cytology (if central lesion)
  • Urine cytology (if central lesion is present, to evaluate for urothelial carcinoma)
  • Complete blood cell (CBC) count with differential
  • Electrolytes
  • Renal profile
  • Liver function tests (LFTs): Aspartate aminotransferase (AST) and alanine aminotransferase (ALT)
  • Serum calcium
  • Other tests as indicated by the patient’s presenting symptoms.
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Computed Tomography and Magnetic Resonance Imaging

Contrast-enhanced computed tomography (CT) scanning has become the imaging procedure of choice for diagnosis and staging of renal cell cancer and has virtually replaced excretory urography and renal ultrasonography. In most cases, CT imaging can differentiate cystic masses from solid masses and supplies information about lymph node, renal vein, and inferior vena cava involvement.

The 2009 American Urological Association (AUA) guideline for the management of the clinical T1 renal mass recommends a high-quality cross-sectional CT or MRI, first without and then with intravenous contrast if renal function is adequate. The objectives are as follows. [21] :

  • Rule out angiomyolipoma
  • Evaluate for locally invasive features
  • Study the involved anatomy
  • Determine the status of the uninvolved kidney and its vasculature

The National Comprehensive Cancer Network (NCCN) guidelines for kidney cancer recommend the following as part of the initial workup [20] :

  • Abdominal/pelvic CT or abdominal MRI with or without contrast, depending on renal insufficiency
  • Chest imaging
  • Brain MRI, if clinically indicated

The NCCN guideline recommends abdominal MRI to assess suspected tumor involvement in the inferior vena cava, or as an alternative to CT for renal mass detection and staging in cases where the use of contrast is contraindicated because of allergy or renal insufficiency. [20]

A study by Sauk et al concluded that multidetector CT imaging characteristics may aid in identifying differences at the cytogenic level among patients with clear cell renal cell carcinomas. Imaging features that proved significant included degree of attenuation and presence of calcifications. [22]

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Percutaneous Cyst Puncture

Percutaneous cyst puncture and fluid analysis is used in the evaluation of potentially malignant cystic renal lesions detected by ultrasonography or computed tomography imaging.

According to the 2009 AUA management guideline, a renal mass core biopsy via a percutaneous approach, with or without fine needle aspiration, is indicated in patients for whom the results might affect approach to treatment. Biopsy is especially appropriate in patients with clinical or radiographic evidence of lymphoma, abscess, or metastasis. [21]

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Histology

Renal cell carcinoma (RCC) has the following five histologic subtypes:

  • Clear cell (75% of cases)
  • Chromophilic (15%)
  • Chromophobic (5%)
  • Oncocytoma (3%)
  • Collecting duct (2%)

Clear cell carcinoma is characterized by unusually clear cells with a cytoplasm rich in lipids and glycogen, and it is most likely to show 3p deletion. Chromophilic tumors tend to be bilateral and multifocal and may have trisomy 7 and/or trisomy 17. Chromophobic carcinoma is characterized by large polygonal cells with pale reticular cytoplasm characterize, and it does not exhibit 3p deletion.

Renal oncocytoma consists predominantly of eosinophilic cells, in a characteristic nested or organoid pattern, that do not exhibit 3p deletion or trisomy 7 or 17. These tumors rarely metastasize.

Collecting duct carcinoma is an unusual variant characterized by a very aggressive clinical course. This disease tends to affect younger patients and may present as local or widespread advanced disease. These cells can have three different types of growth patterns: acinar, sarcomatoid, and tubulopapillary. The sarcomatoid variant, which can occur with any histologic cell type, is associated with a significantly poorer prognosis.

The following table provides a brief summary of the 5 histologic subtypes of renal cell carcinoma.

Table. Pathologic Classification of Renal Cell Carcinoma (Open Table in a new window)

Cell Type Features Growth Pattern Cell of Origin Cytogenetics
Clear cell Most common Acinar or sarcomatoid Proximal tubule 3p-
Chromophilic Bilateral and multifocal Papillary or sarcomatoid Proximal tubule +7, +17, -Y
Chromophobic Indolent course Solid, tubular, or sarcomatoid Cortical collecting duct Hypodiploid
Oncocytic Rarely metastasize Tumor nests Cortical collecting duct Undetermined
Collecting duct Very aggressive Papillary or sarcomatoid Medullary collecting duct Undetermined

Go to Clear Cell Renal Cell Carcinoma and Sarcomatoid and Rhabdoid Renal Cell Carcinoma for complete information on these topics.

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Laboratory Studies

 

 

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Procedures

Cystoscopy and Ureteroscopy if central lesion, to rule out urothelial carcinoma

Biopsy of mass in case of central mass lesions to rule out urothelial carcinoma

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