Renal Carcinoma



Renal Carcinoma


Todd M. Blodgett, MD












































































(T) Primary Tumor

Adapted from 7th edition AJCC Staging Forms.


TNM

Definitions


TX

Primary tumor cannot be assessed


T0

No evidence of primary tumor


T1

Tumor ≤ 7 cm in greatest dimension, limited to the kidney

T1a

Tumor ≤ 4 cm in greatest dimension, limited to the kidney

T1b

Tumor > 4 cm but ≤ 7 cm in greatest dimension, limited to the kidney


T2

Tumor > 7 cm in greatest dimension, limited to the kidney

T2a

Tumor > 7 cm but ≤ 10 cm in greatest dimension, limited to the kidney

T2b

Tumor > 10 cm, limited to the kidney


T3

Tumor extends into major veins or perinephric tissues but not into the ipsilateral adrenal gland and not beyond Gerota fascia

T3a

Tumor grossly extends into the renal vein or its segmental (muscle containing) branches, or tumor invades perirenal &/or renal sinus fat but not beyond Gerota fascia

T3b

Tumor grossly extends into the vena cava below the diaphragm

T3c

Tumor grossly extends into the vena cava above the diaphragm or invades the wall of the vena cava


T4

Tumor invades beyond Gerota fascia (including contiguous extension into the ipsilateral adrenal gland)


(N) Regional Lymph Nodes


NX

Regional lymph nodes cannot be assessed


N0

No regional lymph node metastasis


N1

Metastasis in regional lymph node(s)


(M) Distant Metastasis


M0

No distant metastasis


M1

Distant metastasis










































AJCC Stages/Prognostic Groups

Adapted from 7th edition AJCC Staging Forms.


Stage

T

N

M


I

T1

N0

M0


II

T2

N0

M0


III

T1 or T2

N1

M0

T3

N0 or N1

M0


IV

T4

Any N

M0

Any T

Any N

M1
















































Comparison of Robson and TNM Staging


Robson Stage

Definitions

TNM


I

Tumor ≤ 2.5 cm and confined to kidney

T1

Tumor > 2.5 cm and confined to kidney

T1-T2


II

Tumor extends into perinephric fat or adrenal

T3a if involves perinephric fat, T4 if involves ipsilateral adrenal


IIIA

Tumor invades renal vein

T3a

Tumor extends into inferior vena cava

T3b below the diaphragm


IIIB

Lymph node involvement

N0-N1, M0


IIIC

Involvement of local vasculature and lymph nodes

T3a-c, N0-N1


IVA

Involvement of adjacent organs (except ipsilateral adrenal)

T4


IVB

Distant metastases

M1








Coronal graphic shows a typical T1a lesion image, defined as less than or equal to 4 cm and confined to the kidney.






Axial graphic shows a T1a renal cell carcinoma image, defined as less than or equal to 4 cm and confined to the kidney. Lesions may be exophytic or more centrally located, as is the T1a depicted here.






Coronal graphic shows a typical T1b lesion image, defined as larger than 4 cm but less than or equal to 7 cm and confined to the kidney.






Axial graphic shows a T1b renal cell carcinoma image, defined as larger than 4 cm but less than or equal to 7 cm and confined to the kidney. These lesions may be exophytic but will still be categorized as T1 as long as there is no extension outside of the kidney.







Coronal graphic shows a T2a renal cell carcinoma image, defined as larger than 7 cm but less than or equal to 10 cm and confined to the kidney. These lesions may also be described as exophytic but do not invade outside of the kidney.






Coronal graphic shows a typical T2b renal cell carcinoma image, defined as larger than 10 cm but confined to the kidney.






Coronal graphic shows a T3a renal cell carcinoma with tumor extension image into the perirenal fat but not beyond the confines of Gerota fascia image.






Coronal graphic shows another example of a T3a lesion with extension into the perirenal or renal sinus fat image. Again, the tumor is limited by the confines of Gerota fascia.







Coronal graphic shows a T3a renal cell carcinoma with extension of tumor into the renal vein image. Extension beyond the renal vein into the inferior vena cava would be defined as T3b lesion.






Coronal graphic shows a T3b renal cell carcinoma with extension of tumor not only into the renal vein but also into the inferior vena cava image. T3b lesions do not extend above the diaphragm.






Coronal graphic shows a T3c renal cell carcinoma with involvement of tumor in the renal vein and inferior vena cava, as well as extension of tumor within the inferior vena cava above the diaphragm image.






Coronal graphic shows a T4 renal cell carcinoma with extension into the ipsilateral adrenal gland image.







Coronal graphic shows another example of a T4 lesion with invasion into not only the perirenal fat but also with extension beyond the Gerota fascia image.






Coronal graphic shows retroperitoneal adenopathy on both sides of midline image. N0 disease is classified as no regional lymph node metastasis, while N1 disease is classified as metastatic disease in regional lymph nodes.































image

METASTASES, ORGAN FREQUENCY


Lungs

75%


Soft tissue

35%


Bone

20%


Liver

20%


Adrenal gland

19%


Cutaneous tissues

8%


CNS

8%



25-40% of patients present with metastatic disease.




OVERVIEW


General Comments



  • Represents 2.6% of all cancers


  • Only 2-4% occur in inherited syndromes


  • Renal cell carcinoma (RCC) is most common renal cancer (85%)


  • 2% bilateral involvement


Classification



  • 4 major histopathologic subtypes of renal cell carcinoma



    • Clear cell carcinoma


    • Papillary carcinoma


    • Collecting duct carcinoma


    • Chromophobe renal carcinoma


PATHOLOGY


Routes of Spread



  • Hematogenous, lymphatic, &/or direct invasion


  • 25% may be multifocal in the same kidney


  • Found incidentally at autopsy, in some series in up to 25% of cases


  • 25-40% present with metastatic disease



    • Lung (75%)


    • Soft tissue (35%)


    • Bone (20%)


    • Liver (20%)


    • Cutaneous tissues (8%)


    • CNS (8%)


General Features



  • Comments



    • Renal cell carcinoma arises from renal tubular epithelium


  • Genetics



    • Hereditary papillary RCC



      • Multiple


      • Bilateral


      • Papillary renal tumors


      • Autosomal dominant


      • C-met oncogene on chromosome 7


    • Hereditary leiomyoma and renal cell cancer syndrome



      • Cutaneous leiomyomas


      • Uterine fibroids


      • Renal cell cancer


      • Suspected mutation of fumarate hydratase gene


    • von Hippel-Lindau



      • RCC


      • Retinal angioma


      • Hemangioblastomas


      • Pheochromocytomas and others


      • Mutation of VHL gene on chromosome 3p25


      • RCC develops in approximately 40% of patients with von Hippel-Lindau


      • Major cause of mortality


    • Birt-Hogg-Dubé syndrome



      • Fibrofolliculomas on head and neck


      • Chromophobic RCC or onocytoma


      • Mutation of BDH gene on chromosome 17p


  • Etiology



    • Genetic and environmental causes



      • Genetic



        • Tuberous sclerosis


        • von Hippel-Lindau


        • Birt-Hogg-Dubé syndrome


        • Hereditary papillary RCC


      • Environmental



        • Cigarette smoking: Dose dependent


        • Obesity


        • Hypertension


        • Acquired cystic disease from chronic dialysis


        • Chronic exposure to phenacetin


        • Benzene exposure


        • Cadmium exposure


        • Asbestos exposure


    • Other risk factors



      • Increasing age


      • Male sex


  • Epidemiology & cancer incidence



    • Estimated 2008 incidence: 54,000 cases in USA


    • M:F = 2:1


    • Highest incidence in 6th to 8th decade


  • Associated diseases, abnormalities



    • Multiple paraneoplastic disorders associated with RCC usually caused by tumor release of various cytokines



      • Hypercalcemia


      • Erythrocytosis


      • Polyneuropathy


      • Amyloidosis


      • Hypertension


      • Dermatomyositis


    • Syndromes may resolve after successful treatment of tumor


Gross Pathology & Surgical Features



  • Varies from solid to cystic mass


  • Yellow areas are due to lipid-rich tumor cells


  • May have gray or black areas of necrosis or hemorrhage


Microscopic Pathology



  • H&E



    • Clear cell carcinoma



      • Have clear or granular cytoplasm in round cells


      • Tumors may have solid, trabecular, or tubular pattern


    • Papillary carcinoma



      • Tumor cells are cuboidal or low columnar


      • Tumor pattern is papillary


    • Chromophobe RCC



      • Tumor cell morphology varies, but cells are lightly eosinophilic stained


      • Tumor pattern is solid sheets


IMAGING FINDINGS


Detection



  • T staging accuracy is around 80% with noted difficulty in imaging some retroperitoneal and perinephric areas


  • General T staging imaging characteristics



    • T1: Tumor ≤ 7 cm in greatest dimension, limited to kidney




      • No evidence of perinephric fat or renal fascial involvement


      • Exophytic tumors may not be reliably classified into T1a, T1b, or T2


      • Solid enhancing lesion


    • T2: Tumor > 7 cm in greatest dimension, limited to kidney



      • Imaging may be useful for distinguishing between T2a and T2b lesions


    • T3: Tumor extends into major veins or perinephric tissues but not into ipsilateral adrenal gland and not beyond Gerota fascia



      • Ultrasound and MR very useful to demonstrate venous thrombus and to evaluate possible tumor thrombus



        • In general, thrombi that contain enhancing vessels are tumor


      • Can be used to identify thrombus in renal veins or inferior vena cava (IVC) with accuracy of 87%


    • T4: Tumor invades beyond Gerota fascia or invades IVC above diaphragm



      • Chest CT is recommended for large or aggressive primary tumors


      • Brain MR and bone scans are often performed in patients with suggestive signs or symptoms


      • PET/CT may be useful for identifying possible distant metastases in patients with large primary lesions



        • Debated whether to use for primary detection of metastases or only to verify equivocal CT findings


  • Ultrasound



    • Primary method for differentiating a cyst from a solid lesion


    • Primary tumor may be variably echogenic relative to background renal cortex



      • Isoechoic



        • May be missed on ultrasound, as tumor may be indistinguishable from background renal parenchyma


        • Look for border contour deformity


      • Hypoechoic



        • Differentiated from a cyst by lack of through transmission


      • Hyperechoic



        • Tend to be smaller


        • May look similar to angiomyolipomas


    • Large lesions often heterogeneous in echotexture


  • CT



    • NECT and parenchymal phase CECT are necessary for all patients unless contraindicated


    • NECT



      • Variable appearance



        • Small lesions may be homogeneous in attenuation


        • Larger lesions often show central necrosis


        • May have calcifications


        • Almost never contain macroscopic fat


        • May also be primarily cystic


      • Low attenuation



        • Papillary RCCs


      • Moderate attenuation



        • May be chromophobe RCC or angiomyolipoma (soft tissue component of mass, lipomatous areas will be low density)


      • High attenuation



        • Clear cell RCC lesions often have mixed pattern


        • High-attenuation regions represent soft tissue areas, while low-attenuation regions are necrotic or cystic


        • Oncocytomas may have a similar appearance on CT


      • Pseudocapsule may be seen as high-density ring surrounding tumor


    • CECT



      • Renal mass protocol includes



        • Thin slice 1.25-2.5 mm


        • Noncontrast and contrast-enhanced acquisitions


        • Arterial phase with 20 second delay helpful for evaluating arterial vessels


        • Nephrographic phase with 60-70 second delay best for evaluating parenchyma


        • Delayed phase with 5-10 minutes delay best for evaluating collecting system


        • Coronal reformatted images also helpful for better defining relationship of tumor to other structures


      • Enhancement pattern during nephrographic phase is most useful for determining type of tumor


      • Gold standard for detection and staging is CT


      • RCCs have variable enhancement patterns



        • Some will enhance briskly


        • Papillary RCCs may have very little enhancement (can be mistaken for a hyperdense cyst with pseudoenhancement)


        • Solid enhancing mass in the kidney is RCC until proven otherwise


  • MR



    • In general, similar findings to CT


    • Variable signal characteristics and enhancement pattern


    • Typically iso- to hypointense compared to normal renal cortex on T1-weighted images


    • Typically hyperintense on T2-weighted images


    • Cystic RCCs will generally have enhancing septa or mural nodularity


  • PET/CT



    • Similar findings on CT portion of exam as those discussed above


    • RCCs have variable FDG avidity



      • More helpful when intensely FDG avid


      • Solid mass without FDG activity can still be RCC


      • Not generally used to differentiate benign from malignant renal masses


  • Image-guided biopsies



    • Not routinely done


    • Can be performed for problem solving



      • e.g., in a patient with a different primary malignancy for differentiating metastasis from primary renal malignancy


Staging



  • Nodal



    • Ultrasound



      • Not used for nodal or metastatic evaluation



      • Can be used for problem solving with lesions seen in other organs, e.g., liver


      • Can be used to evaluate renal vessels and IVC for patency



        • CT with contrast likely better to look for vascular invasion


    • CT



      • Gold standard for detection of nodes and for evaluation of vascular structures


      • Nodes may hyperenhance


      • Smaller nodes may appear normal


      • Larger nodal metastases may be heterogeneous or have central necrosis


      • Best modality for looking at invasion of perinephric fat and other local structures


    • MR



      • Typically reserved for patients with renal insufficiency or contraindications for CT contrast


      • Particularly useful for determining invasion and extent of involvement into IVC


    • PET/CT



      • For RCC metastases using FDG PET



        • Sensitivity (63%), specificity (100%), PPV (100%)


        • Higher than CT alone


      • For identification and characterization of primary RCC tumors



        • Sensitivity (47%), specificity (80%), accuracy (51%)


        • Lower than CT alone


        • False-negatives are due to urinary excretion of tracer in some tumors


      • Lesions ≤ 1 cm have far lower sensitivity due to scanner limitations


    • CTA or MRA



      • Can be helpful in establishing tumor relation to vascular supplies


      • Also potentially useful for nephron sparing or laparoscopic procedures


  • Metastatic disease



    • Metastatic location frequencies



      • Lung (75%)


      • Soft tissue (35%)


      • Bone (20%)


      • Liver (20%)


      • Adrenal glands (19%)


      • Cutaneous tissues (8%)


      • CNS (8%)


    • CT



      • Tumor extension or thrombus via renal vein (23%), inferior vena cava (7%)


      • Usually seen as hypervascular metastases


    • MR



      • On T1 post-contrast imaging, RCC usually enhances less than renal tissue


      • Multiplanar capacity of MR allows ideal assessment of renal vein and IVC


      • Preferred to evaluate for intracranial metastases


      • Staging with MR is equal or better to CT


    • PET/CT



      • FDG uptake by RCC primary or metastatic lesion is variable


      • PET and PET/CT are more clinically helpful when positive


      • Negative exam may be true negative or non-FDG-avid RCC


      • 80-100% specific for bony metastases


Restaging



  • Ultrasound



    • Risk increases without clean surgical margins


    • Small bowel occupying nephrectomy bed can be mistaken for recurrence


    • Ultrasound is not acceptable for monitoring nephrectomy bed


  • CT



    • Useful to follow patients after treatment


    • 20-30% of patients with apparent localized renal cell carcinoma at time of surgery relapse following radical nephrectomy



      • Majority are distant metastases


      • Usually relapse within 3 years


    • Lung metastases are most common late relapse finding



      • May appear as hemorrhagic metastases, show lymphatic invasion, or produce consolidation


    • Bone metastases are less common


    • Rarely, pancreatic lesions are identified


  • MR



    • MR is superior to CT in assessing venous involvement


    • CT is currently preferred to MR in following patients for disease recurrence after surgery


  • PET/CT



    • Nephrectomy bed has highest area of recurrence (20-40%)


    • Partial nephrectomy patients should have remnant carefully evaluated



      • Recurrence rates in remnant are 4-6% within 2-4 years, depending on stage


      • Some recurrence may be from incomplete margins, while others represent multifocal disease


    • Thoracic involvement should be evaluated by CT


    • Bone scan and brain MR may be performed with appropriate clinical indications


    • PET/CT has been shown useful for both local recurrence and metastases


    • Metastatic frequency by tumor stage



      • T1 disease (7.1%)


      • T2 disease (26.5%)


      • T3 disease (39.4%)


CLINICAL ISSUES


Presentation



  • “Classic” triad



    • Hematuria


    • Flank pain


    • Abdominal mass


  • < 15% of patients present with classic triad


  • Other signs and symptoms include



    • Weight loss


    • Fever


    • Hypercalcemia


    • Night sweats


    • Malaise


    • Hypertension



  • Roughly half of cases are identified as incidental finding on imaging


  • Remainder are suspected based on



    • Various symptoms of paraneoplastic syndromes


    • Direct effects of tumor metastasis


    • Identification of palpable renal mass


Cancer Natural History & Prognosis



  • 5-year survival by stage



    • T1a N0 M0 (70-90%)


    • T1b N0 M0 (80-90%)


    • T2 N0 M0 (70-80%)


    • Organ confined, T1-T2 N0 M0 (70-90%)


    • Invasion of perinephric fat, T3a N0 M0 (60-80%)


    • Venous involvement, T3b-T3c N0 M0 (40-65%)


    • Adrenal involvement, T4 N0 M0 (0-30%)


    • Locally advanced, T4 N0 M0 (0-20%)


    • Lymph involvement, any T, N+, M0 (0-20%)


    • Systemic metastases, any T, any N, M1 (0-10%)


Treatment Options



  • Major treatment alternatives



    • Surgery is treatment of choice unless late stage


    • Alternatives



      • Radiofrequency ablation


      • Cryoablation


      • Ultrasound ablation


      • Microwave radiotherapy


    • Currently no recommendation for adjuvant therapy for resection of primary tumor


  • Major treatment roadblocks



    • RCC typically have high levels of MDR protein, making chemotherapy difficult


  • Treatment options by primary tumor stage



    • T1a: Nephron-sparing surgery preferred, radical nephrectomy in some selected patients


    • T1b-T2: Radical nephrectomy recommended, laparoscopic preferred


    • T3-T4: Radical open nephrectomy recommended


REPORTING CHECKLIST


T Staging



  • Ideally, report should include bidirectional axial dimensions and coronal dimension


  • Report any obvious or questionable spread outside of kidney into Gerota fascia


N Staging



  • Report size and confidence level of all retroperitoneal nodes near level of renal veins


  • Any nodes > 1 cm should be reported as suspicious


  • Nodes ≤ 1 cm should be reported as indeterminate


  • Look for additional features of central necrosis or hyperenhancement


M Staging



  • Must report whether there is adrenal involvement, as this may affect whether a radical nephrectomy will be performed



    • If there is adrenal asymmetry or nodularity, consider further evaluation prior to surgery



SELECTED REFERENCES

1. American Joint Committee on Cancer: AJCC Cancer Staging Manual. 7th ed. New York: Springer, 2010

2. Bach AM et al: Contemporary radiologic imaging of renal cortical tumors. Urol Clin North Am. 35(4):593-604; vi, 2008

3. Hinshaw JL et al: Comparison of percutaneous and laparoscopic cryoablation for the treatment of solid renal masses. AJR Am J Roentgenol. 191(4):1159-68, 2008

4. Zhang J et al: Imaging of kidney cancer. Radiol Clin North Am. 45(1):119-47, 2007

5. Blitman NM et al: Renal medullary carcinoma: CT and MRI features. AJR Am J Roentgenol. 185(1):268-72, 2005

6. Ergen FB et al: MRI for preoperative staging of renal cell carcinoma using the 1997 TNM classification: comparison with surgical and pathologic staging. AJR Am J Roentgenol. 182(1):217-25, 2004

7. Reznek RH: CT/MRI in staging renal cell carcinoma. Cancer Imaging. 4 Spec No A:S25-32, 2004

8. Israel GM et al: Renal imaging for diagnosis and staging of renal cell carcinoma. Urol Clin North Am. 30(3):499-514, 2003

9. Walter C et al: Imaging of renal lesions: evaluation of fast MRI and helical CT. Br J Radiol. 76(910):696-703, 2003

10. Kim JK et al: Differentiation of subtypes of renal cell carcinoma on helical CT scans. AJR Am J Roentgenol. 178(6):1499-506, 2002

11. Ramdave S et al: Clinical role of F-18 fluorodeoxyglucose positron emission tomography for detection and management of renal cell carcinoma. J Urol. 166(3):825-30, 2001

12. Vasselli JR et al: Lack of retroperitoneal lymphadenopathy predicts survival of patients with metastatic renal cell carcinoma. J Urol. 166(1):68-72, 2001

13. Coll DM et al: 3-dimensional volume rendered computerized tomography for preoperative evaluation and intraoperative treatment of patients undergoing nephron sparing surgery. J Urol. 161(4):1097-102, 1999

14. Bechtold RE et al: Imaging approach to staging of renal cell carcinoma. Urol Clin North Am. 24(3):507-22, 1997

15. Kopka L et al: Dual-phase helical CT of the kidney: value of the corticomedullary and nephrographic phase for evaluation of renal lesions and preoperative staging of renal cell carcinoma. AJR Am J Roentgenol. 169(6):1573-8, 1997

16. Jamis-Dow CA et al: Small (< or = 3-cm) renal masses: detection with CT versus US and pathologic correlation. Radiology. 198(3):785-8, 1996

17. Curry NS: Small renal masses (lesions smaller than 3 cm): imaging evaluation and management. AJR Am J Roentgenol. 164(2):355-62, 1995

18. Newhouse JH: The radiologic evaluation of the patient with renal cancer. Urol Clin North Am. 20(2):231-46, 1993

19. Yamashita Y et al: Small renal cell carcinoma: pathologic and radiologic correlation. Radiology. 184(2):493-8, 1992

20. McClennan BL: Oncologic imaging. Staging and followup of renal and adrenal carcinoma. Cancer. 67(4 Suppl):1199-208, 1991

21. Fein AB et al: Diagnosis and staging of renal cell carcinoma: a comparison of MR imaging and CT. AJR Am J Roentgenol. 148(4):749-53, 1987

22. Hricak H et al: Magnetic resonance imaging in the diagnosis and staging of renal and perirenal neoplasms. Radiology. 154(3):709-15, 1985

23. Mauro MA et al: Renal cell carcinoma: angiography in the CT era. AJR Am J Roentgenol. 139(6):1135-8, 1982






Image Gallery









(Left) Axial CECT shows a small (just over 1 cm), low-attenuation, enhancing lesion image in the posterior mid pole right kidney. Although nonspecific, the enhancement makes this suspicious for a renal cell carcinoma. (Right) Axial PET/CT shows focal FDG within the pathologically confirmed T1a renal cell carcinoma image in the right kidney. Renal cell carcinomas have variable FDG uptake, but intensely FDG-avid lesions should be viewed as very suspicious. Note the gallstones image.

Only gold members can continue reading. Log In or Register to continue

Related posts:

Testicular Carcinoma 3 38 66 Male Pelvis Default ThumbnailE

Stay updated, free articles. Join our Telegram channel
Tags:
Sep 18, 2016 | Posted by in GENITOURINARY IMAGING | Comments Off on Renal Carcinoma

Full access? Get Clinical Tree

 Get Clinical Tree app for offline access