Ultrasound of the urinary tract - Renal tumors

transcript

Ultrasound of the urinary tract

Renal tumors

Samir Haffar M.D.

Department of Internal Medicine

Ultrasound of renal tumors

• US is often the first imaging modality of kidneys

• Plays important role in diagnosis of renal tumors

• Technical advances improved detection of renal tumorsTissue harmonic imaging (THI)Color Flow Doppler Contrast-enhanced Doppler

CT is the gold standard for detection &characterizationof renal mass lesions

Normal kidney

Paspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 – 41.

Benign & malignant renal tumors

Pseudo-lesions of kidney

Benign tumors

Malignant tumors: Renal cell carcinoma Tumors of renal collecting

system

Renal metastases

Renal lymphoma

Leukemic involvement of kidney

Percutaneous biopsy for renal massesPaspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 – 41.

Pseudo-lesions of kidney

• Congenital normal variants Dromedary hump Persistent fetal lobulation Prominent column of Bertin Junctional parenchymal defect Hypoechoic renal sinus

• Inflammatory lesions Focal bacterial nephritis “clinical context” Renal abscess

Dromedary humpCommon renal variation

Focal bulge on lateral border of left kidneyResult from adaptation of renal surface to adjacent spleen

Easily differentiated from renal mass: US – Doppler

Persistent fetal lobulation

Renal surface indentations between pyramidsMay be single or multiple

Persistent fetal lobulationRenal surface indentations between pyramids

Multiple fetal lobulations

Prominent column of Bertin (PCB)Mistaken for intrarenal tumor

Continuity with renal cortex

Similar echo as renal parenchyma

Less than 3 cm in size

Contains renal pyramids

Similar vascular pattern by color Doppler

Prominent column of Bertin (PCB)

Medullary pyramids seen within PCB

Sagittal sonogramClassic appearance

Transverse sonogramClassic appearance

Rumack CM et al. Diagnostic Ultrasound. Elsevier-Mosby, St. Louis, USA, 3rd edition, 2005.

Parenchymal junctional defect

Commonly mistaken for cortical scar or angiomyolipoma

Continuity with central sinus

by echogenic line

Triangular hyperechoic structureAntero-superior or postero-inferior

surface of kidney “interrenicular septum”

Hypoechoic renal sinus

Fat-filled hypoechoic renal sinus mimicking mass lesionAbsence of a well-defined margin

Normal vessels traversing renal sinus by CFD

Benign renal tumors

• Angiomyolipoma Sporadic – Associated with TS• Adenoma Benign counterpart of RCC

Tumors < 3 cm rarely metastasize• Oncocytoma Tumor of renal tubular origin

Differentiation from RCC difficultHypo, iso, or hyperechoic to cortex

• LeiomyomaRare, peripheral or centralSolid, mixed, or cystic lesion

• Reninoma• Hemangiopericytoma

Angiomyolipoma (AML)Hamartoma (mature adipose tissue, SM, blood vessels)

• Sporadic (80%) Middle-aged women, unilateralTuberous sclerosis (20%) Younger, multiple, bilateral, larger

• Grows during pregnancy & presents with hemorrhageRetroperitoneal bleeding (Wunderlich’s syndrome):10%Risk of rupture: > 4 cm – microaneurysms > 5 mm

• Management: observation – embolization – renal-sparing surg

Overlap between imaging features of AML & small RCC

Sonography of angiomyolipoma

• Classic pattern Well-defined hyperechoic mass Posterior acoustic shadowing

Small RCC Well-defined hyperechoic mass Hypoechoic rim Intratumoral cystic changes

• Hypoechoic pattern Vessels or bleeding predominate

• Hemorrhagic pattern Central – perirenal

Depends on proportion of fat, SM, vessels & bleeding

Angiomyolipoma – Classic pattern

CT (excretory phase)

Fat attenuation lesionHousehold unit of – 8

Well defined hyperechoic massPosterior acoustic shadowing

Longitudinal US of right kidney

Intra-tumoral fat on CT almost confirms diagnosis of AML

Renal intratumoral fat attenuation

Logue LG et al. RadioGraphics 2003; 23:241–246

Almost pathognomonic for AML

Rare benign & malignant tumors considered

• Renal cell carcinoma

• Lipoma & liposarcoma

• Myolipoma

• Oncocytoma

• Wilms tumor

Angiomyolipomas (AMLs)

Large exophytic AML Large exophytic AMLCentral hemorrhage

Exophytic AMLPerirenal hematoma

Atraumatic renal & perirenal hemorrhage

• Malignant renal tumorsMost common cause

• Benign renal tumors AMLs

• Vasculitis

• Aneurysm

• Systemic anticoagulation

• Infection

• Nephritis

Tuberous sclerosis / Bourneville diseaseAutosomal dominant disease (prevalence: 1/10 000)

• Hamartomatous growth CNS, eye, skin, heart, liver, kidney• Classic clinical triad Mental retardation

Seizures Adenoma sebaceum

(angiofibroma)• CNS manifestations Subependymal hamartomas

(90%) Giant cell astrocytomas• Renal manifestations Angiomyolipomas (AMLs)

(50%) Renal cysts Renal cell carcinomas (RCC)

Tuberous sclerosis (Bourneville disease)

Features central to diagnosis Adenoma sebaceum Nontraumatic ungual periungual fibroma Hypomelanotic macules (three or more) Shagreen patch (connective tissue nevus) Multiple retinal nodular hamartomas Subependymal nodule Subependymal giant cell astrocytoma Cardiac rhabdomyoma (single or multiple) Renal angiomyolipoma

Less specific features

Multiple pits in dental enamel Hamartomatous rectal polyps Bone cysts Gingival fibroma Retinal achromic patch “Confetti”skin lesions Multiple renal cysts

Tuberous sclerosisMultiple subependymal hamartomas

T2 axial MR of brain T2 coronal MR of brain

Weber TM. Ultrasound Clin 2006 ; 1 : 15 – 24.

Primary diagnostic feature

Renal cysts seen in cortex & medullaAppear at an earlier age than cysts seen in APKD

Tuberous sclerosisMultiple renal cysts

Not primary diagnostic feature

Malignant renal tumors

Renal cell carcinoma

Tumors of renal collecting system

Renal cell carcinomaMost common primary malignancy of kidney

• 2% of all malignancies

• Increase incidence of RCC

• Improved survival rates

• Improved imaging technique & early diagnosis

• Classified histologically into five main types

• Mainly sporadic in occurrence, 4% familial in nature

WHO classification of renal cell carcinoma – 2004Type Incidence Grade Imaging features

Clear cell carcinoma 70 – 80%

Low-grade tumor Poor enhancement

Papillary type Type 1 Type 2

10 – 15% Low-grade tumor Aggressive tumor

Poor enhancement Intense enhancement

Chromophobe type 5% – –

Collecting duct type < 1% Aggressive tumor –

Medullary carcinoma < 1% Aggressive tumor Common in sickle cell trait

Imaging cannot differentiate different histologic types of RCCs

Clinical presentation of RCC

• Clinical triad Hematuria < 10% Abdominal pain Abdominal mass

• Paraneoplastic synd Anemia, fever, hypertension, 20 – 40% hypercalcemia, hepatic dysfunction

• Stauffer syndrome Nonmetastatic IH cholestasis Rare Tumor-induced inflammatory response Reversible after resection of tumor

• Left-sided varicocele Renal vein involvement 2%

Sonographic findings of RCC

• Hyperechoic mass < 3 cm – differentiated from AML Anechoic rim (pseudocapsule) Intratumoral cystic changes

• Isoechoic mass Differentiated from pseudo-tumors Power Doppler & CEUS

• Hypoechoic mass

• Cystic mass (15%) Extensive necrosis of tumor Multilocular Cystic RCC (MCRCC)

Renal cell carcinoma

Hypoechoic massin lower pole

Gray-scale US Color Doppler

Presence of vascularity

Pulsed Doppler

Arterial wave

RCC & arteriovenous fistula

Prando A et al. RadioGraphics 2006 ; 26 : 233 – 244.

Large A-V fistula within renal tumorFistula associated with intense venous flow to left renal vein

& periureteral veins causing ureteral notching

Intrarenal & venous propagation of RCC

Intrarenal propagation of lower-pole RCC to upper poleRenal vein thrombus, IVC invasion,

& extensive collateral venous circulation

Prando A et al. RadioGraphics 2006 ; 26 : 233 – 244.

Intrarenal propagation of RCC

Exophytic hypoechoic solid mass (M)Unusual diffuse hypoechogenicity of renal parenchyma (*)

Longitudinal US image of left kidney

Prasad SR et al. RadioGraphics 2006 ; 26 : 1795 – 1810.

Venous thrombosis in RCC

Enormous thrombus distending LRVas it crosses midline anterior to aorta

Transverse sonogram

Large thrombus of IVC thatterminates caudal to level of HV

Sagittal sonogram of IVC

ADPKD & solid mass

Solid renal masses in right kidney

Papillary renal cell carcinoma following nephrectomyNo increased risk for RCC in ADPKD except risk related to dialysis

Acquired cystic kidney disease with dialysisACKDD

Shrunken end-stage kidneysFrequency increases with duration of dialysis

Complications: infection, hemorrhage, stone, erythocytosis, neoplasmScreen native kidneys even after RT

Bates J A. Abdominal Ultrasound: How, Why and When. Churchill Livingstone, Edinburg, UK, 2nd edition, 2004

Collecting duct carcinoma< 1% of RCCs – Aggressive neoplasm

Prasad SR et al. RadioGraphics 2006 ; 26 : 1795 – 1810.

Solid hypovascular medullary neoplasm

Power Doppler sonogram

Cystic growth patterns of renal cell carcinoma

Yamashita Y et al. Acta Radiologica 1994 ; 35 : 19 – 24.Rumack CM et al. Diagnostic Ultrasound. Elsevier-Mosby, St. Louis, USA, 3rd edition, 2005.

Multilocular

Unilocular

Cystic necrosis

Origin in wall of simple cyst

Multilocular Cystic RCC (MCRCC)3% of all RCCs

Kim JC et al. Korean J Radiol 2000 ; 1 : 104 – 109.

Multiloculated cystic massEnhanced thin septa without nodules

Some enhanced solid portions

Multilocular cystic masMultiple echogenic thin septaEchogenic debris (blood clots)

Longitudinal US of right kidney

Cystic renal cell carcinoma

Complex cystic mass4 thick internal septa

US of right kidney CECT

Enhancing soft-tissue components within cyst

US 4 years later

Cystic mass with severalsolid nodular components

Bosniak category III Bosniak category IV

Adilson P et al. RadioGraphics 2006 ; 26 : 233 – 244.

Bosniak classification of renal cystsCategory CT features Significance

Class I Water density homogenous Noncalcified, smooth marginNo enhancing component

Benign

Chapple CR et al. Practical urology: Essential principles & practice.Springer-Verlag, London , 2011.

Class II Thin septae (<1 mm)Thin calcification (<1 mm)Hemorrhagic cyst

Benign

Class IIF Likely benignFollow-up imaging indicated

Class III Thick septaThick calcificationThick wall Multilocular +/− enhancement

≈ 50% malignant

Class IV Criteria of category III Enhancing solid mass of wall or septa

Definitely malignant

Systematic screening for RCC by US

• 2-year screening program for general population (≥ 40 years)• 2 urology departments at Mainz & Wuppertal university hospitals• GP, internists & urologists experienced in renal US• Equivocal or positive renal mass: referral to urology departments• 9959 volunteers in first year, 79% returned in second year• 13 subjects have renal mass (0.1%), 9 were RCC• PPV of positive finding 50% & for equivocal finding 2%

Filipas D et al. BJU Int 2003 ; 91 : 595 – 9.

Screening program accepted by physicians & eligible populationEffective method if equivocal findings reassessed by reference

US before using further imaging studies (CT or MRI)

Sporadic & hereditary renal cancers

Choyke PL et al. Radiology 2003 ; 226 : 33 – 46.

Sporadic renal cancer96%

Hereditary renal cancer4%

Single Multiple & bilateral

Advanced age Younger age More common in men Equal frequency in both sexes Detected at larger size Detected at smaller size (screening)

Hereditary renal cancers

• von Hippel-Lindau disease (VHL)• Tuberous sclerosis (TS)• Hereditary papillary renal cancer• Birt-Hogg-Dubé syndrome• Hereditary leiomyoma renal cell carcinoma• Familial renal oncocytoma & oncocytomatosis• Hereditary nonpolyposis colon cancer (HNPCC)• Medullary carcinoma of kidney (sickle cell trait)

von Hippel-Lindau disease Rare disease (prevalence 1/ 35.000 – 40.000)

• Autosomal dominant disease with high penetrance

• Development of variety of benign & malignant tumors

• Broad clinical manifestations: 40 lesions in 14 organs

• Diagnostic criteria More than one CNS hemangioblastomaOne CNS hemangioblastoma & visceral manifestationsAny manifestation & familial history of VHL disease

Manifestations of VHL Disease40 different lesions in 14 different organs

Leung RS et al.. RadioGraphics 2008 ; 28 : 65 – 79.

Manifestations Prevalence

Pancreatic cysts Cerebellar hemangioblastoma Renal cysts Retinal hemangioblastoma Renal cell carcinoma Spinal cord hemangioblastoma Pheochromocytoma Neuroendocrine tumor of pancreas Serous cystadenoma of pancreas Medullary hemangioblastoma

Papillary cystadenoma of epididymis

50 – 91%44 – 72%59 – 63%45 – 59%24 – 45%13 – 59%

0 – 60%

5 – 17%12 %5 %

10 – 60%

Manifestations of VHL Disease40 different lesions in 14 different organs

Manifestations Prevalence

Pancreatic cysts Cerebellar hemangioblastoma Renal cysts Retinal hemangioblastoma Renal cell carcinoma Spinal cord hemangioblastoma Pheochromocytoma Neuroendocrine tumor of pancreas Serous cystadenoma of pancreas Medullary hemangioblastoma

Papillary cystadenoma of epididymis

50 – 91%44 – 72%59 – 63%45 – 59%24 – 45%13 – 59%

0 – 60%

5 – 17%12 %5 %

10 – 60%

Retinal hemangioblastoma

Retinal angioma

Well defined orange-red massProminent feeding artery

Prominent draining vein

Ophthalmoscopic image Fluorescein angiogram

Retinal angioma withits hyperfluorescence

von Hippel-Lindau disease (VHL)Renal cysts (60%)

Simple renal cyst

Complex renal cyst

Thick wallsSepta

Mural nodules

Anechoic contentsSharply defined smooth wallPosterior acoustic shadowing

Multiple lesions of mixed echotextureMultiple RCCs

von Hippel-Lindau disease (VHL)Renal cell carcinoma (25 – 45%)

Sagittal US of left kidney CECT scan

Simple cysts Solid enhancing lesions

Right nephrectomy (RCCs)CBD stent (pancreatic cysts)

Screening protocol for VHL disease

Body System Regimen Follow-up

Renal Annual abdominal US from 10 y CT or MR Depending on US findings

CNS MRI of brain & spine at 20 y Annual neurologic exam if

symptoms

Repeat imaging if suspicion

Adrenal Annual 24-h urinary VMA from 10 y Annual blood pressure measurement

Imaging if VMA abnormal

Ophthalmic

Annual ophthalmoscopy from 5 y With or without fluorescein

Auditory QuestionnaireAudiogram if questionnaire positive

MRI If audiogram abnormal

Birt-Hogg-Dubé syndromeFibrofolliculomas, pulmonary cysts, & renal tumors

Transverse chest CT scanSeveral small pulmonary cysts

Asymptomatic 38-year-old woman Screening because of family history of this syndrome

Transverse abdominal CT scanMultiple solid renal cancers

Chromophobe carcinomas at surgery

Clinical criteria for diagnosis of HNPCC*

Amsterdam criteria II

• At least 3 relatives with HNPCC-associated cancer:CRC, endometrium, small bowel, ureter, or renal pelvis

• One should be a first-degree relative of the other 2

• At least 1 should be diagnosed before age 50

• At least 2 successive generations should be affected

• Familial adenomatous polyposis should be excluded

• Tumors should be verified by pathological examination

* HNPCC: Hereditary Non-Polyposis Colon Cancer Vasen HFA et al. Gastroenterology 1999 ; 116 : 1453 – 8.

Screening for hereditary renal cancerNo established guidelines

Number of generalizations can be made

CT scan is the best single choice for screening

MRI if patients cannot undergo CECT (RF, allergy)

US not recommended (insensitive for small renal masses)

Mild phenotype Imaging every 2 – 3 years

Aggressive phenotype Imaging every 3 – 6 months

Intervals vary Longer interval for small lesions

Uroepithelial tumors of renal collecting system

• Transitional cell carcinomas (TCC) 90%

• Squamous cell carcinomas 5-0%

• Adenocarcinomas < 1%

Transitional cell carcinoma

Mass in renal pelvis causing slight hydronephrosisin keeping with transitional cell carcinoma

Chapple CR et al. Practical urology: essential principles and practice.Springer-Verlag, London , 2011.

Transitional cell carcinomaTissue harmonic imaging (THI)

Schmidt T et al. AJR 2003 ; 180 : 1639 – 1647.

Fundamental B-mode sonogram

Tumor of upper pole of kidney Slightly hypoechoic to renal sinusBorder of process not well defined

Phase-inversion THI

Fewer scattering artifactsTumor better delineated

Internal structure of process visible

Better lateral & axial resolution Enhanced signal-to-noise ratio Reduced artifacts

Theoretic advantages of THI

Less degradation of sonographic images

Causes of upper tract filling defects

• Calculus

• Thrombus

• Tumor

• Sloughed papilla

• Fungus ball

• Pyelo-ureteritis cystica

Pyeloureteritis cysticaRare abnormality (200 published cases)

• Older individuals, males = females, bilateral in 1/3• Cause: irritating agent on epithelium especially infection• Epithelial bodies below mucosa: cell nests of von Brunn• Not appear to be premalignant lesion• Symptoms: accidental, lumbar pain, UTI, hematuria• IVP or retrograde urography is gold standard for dg

Multiple small (2–3mm) smooth filling defects• No specific treatment

Salpigidis G et al. Hipokratia 2010, 14, 4 : 284 – 285.

Pyeloureteritis cystica

Duplex collecting systemMultiple rounded filling defects within left renal pelvis & ureters

Squamous cell carcinoma

Enlarged kidneyChunky calcification with AS

Longitudinal US of left kidney CFD of left kidney

Increased vascularity in the mass

Large areas of necrosis

Difficult to differentiate from XGPN by imaging

Renal metastases

Renal metastasesMultiple hypoechoic mass

Most common primary tumors: lung, breast, GIT, & melanomaMost common appearance: multiple hypoechoic cortical masses

Usually asymptomatic

Renal metastases

Multiple hyperechoic mass

Right kidney Left kidney

Schmidt T et al. AJR 2003 ; 180 : 1639 – 1647.

Metastatis of small cell bronchial carcinomaTissue harmonic imaging (THI)

Fundamental B-mode sonogram

Suspicious hypoechoic lesionadjacent to right kidney

Phase-inversion THI

Clear solid exophytic massHypoechoic rim (arrow)

Features of kidney clearly delineated

Renal lymphoma

Solitary lesion Multiple lesions Diffuse infiltration of one or both kidneys Renal sinus involvement Preferential involvement of perinephric space Direct extension from retroperitoneal adenopathy

Wide variety of manifestations

Sheth S et al. RadioGraphics 2006 ; 26 : 1151 – 1168.

Unless renal lesion manifests in setting of widespread lymphoma, percutaneous biopsy is indicated

Renal lymphomaSolitary lesion (10 – 25% of patients)

CECT scan

Low-attenuation mass in left kidneythick walls lesion

Stranding in perinephric space

Transverse US of left kidney

Complex partially cystic massThick wall & multiple septa

Minimal through transmission

Renal lymphomaMultiple lesions (Most common, 50 – 60%)

Hypoechoic parenchymal massesNormal shape of kidney

Transverse US of right kidney

CECT scan

Bilateral renal massesLower attenuation than cortex

Paraaortic retroperitoneal adenopathy

Renal lymphoma

Diffuse infiltration of one or both kidneys

Longitudinal gray-scale US of left kidneyNephromegaly without distortion of the normal shape

More common in Burkitt lymphoma (disseminated or limited)

14.8 cm

Renal lymphomaRenal sinus involvement – Uncommon

Poorly defined infiltratingmass in renal pelvis

Sagittal US of left kidney Color Doppler US

Well vascularized kidney Hypovascular mass

Renal lymphomaPreferential involvement of perinephric space (10% )

Differential diagnosis Sarcoma from renal capsule Metastases to perinephric space Perinephric hematoma Retroperitoneal fibrosis Amyloidosis Extramedullary hematopoiesis

Surrounding hypoechoic

perirenal mass

Renal lymphoma

Direct extension from retroperitoneal adenopathy

Large hypoechoic massdisplacing & infiltrating left kidney

Mild hydronephrosis

Sagittal US of left kidney Transverse color Doppler

Mass encasing left renal artery& vein

Leukemic involvement of kidney (rare)

• Focal renal mass (chloromas) Acute myelogenous leukemia: seen in 10% of patientsAcute lymphocytic leukemia: less commonFocal hypovascular soft-tissue masses in one or both kidneys

• Diffusely infiltrating renal mass • Perirenal mass

Perinephric extension of renal lesionIsolated leukemic involvement

Surabhi VR et al. RadioGraphics 2008 ; 28 : 1005 – 1017.

Nonspecific imaging findingsBiopsy required to obtain definitive diagnosis

Pickhardt PJ et all. Radiographics 2000 ; 20 : 215 – 243.

Leukemia in a 3-year-old boy with hypertensionLongituinal sonogram of right kidney

Enlarged heterogenous kidneyLoss of normal corticomedullary differentiation

Percutaneous biopsy in renal masses

Role of percutaneous biopsy in renal masses

Silverman SG et al. Radiology 2006 ; 240 : 6 – 22.

Established indications (sufficient data)

Emerging indications (more studies needed)

• Renal mass & known extrarenal primary malignancy• Renal mass & findings suggesting unresectable renal cancer• Renal mass & surgical comorbidities• Renal mass that may be caused by infection

• Small, hyperattenuating, homogeneously enhancing renal mass• Renal mass for which percutaneous ablation is considered• Indeterminate cystic renal mass

Complications of renal biopsy for mass

• Bleeding Most frequent complicationUsually subclinical (90% by CT)Major bleeding (transfusion) uncommonPA & A-V fistula: months after biopsy

• Pneumothorax Uncommon

• Seeding along needle track: extremely rare (0.01%)

Silverman SG et al. Radiology 2006 ; 240 : 6 – 22.

Thank You

Ultrasound of the urinary tract - Renal tumors

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