Mark Monahan, M.D. Virginia Urology Renal Masses Mark Monahan, M.D. Virginia Urology

Campbell-Walsh Urology, Tenth Edition

Outline Differentiating benign from malignant lesions RCC epidemiology, evaluation and primary treatment Renal cysts Angiomyolipoma What’s New in 2017

Initial Evaluation and Imaging With proper history and imaging, primary care physicians can correctly identify the majority of renal masses, which are simple cysts (50 percent by 50 years old) If the renal lesion in question appears cystic, it must be characterized as simple or complex (Bosniak classification) Any renal mass that is not clearly a simple cyst by strict ultrasound criteria warrants evaluation by CT/MRI (if possible) and urology referral

Imaging A renal mass protocol CT of the abdomen and pelvis are required for the initial work-up and staging (+chest imaging if suspicious for RCC) MRI is generally used to evaluate for tumor thrombus in the renal vein and IVC, but may also be used when CT contrast is contraindicated A central mass may suggest urothelial carcinoma and therefore urine cytology and endoscopic evaluation is generally considered Bone scan, brain imaging and PET scans are not a routine part of initial evaluation

CT Limitations In one study, the rate of contrast nephropathy in patients with a GFR > 40 was 0.6% and < 40 was 4.6% Threshold of 45 is often the cut-off for many radiologists CIN is 3rd most common cause of hospital acquired renal failure (usually after intra-arterial injection)

MRI Limitations GFR is 30-59 (stage 3 chronic kidney disease): use minimum dose of gadolinium (20 mL) GFR is less than 30 (stages 4 and 5 chronic kidney disease): gadolinium is NOT recommended, unless the patient is on hemodialysis Minimal risk of nephrogenic systemic fibrosis (NSF) in patients with renal failure (Deo et al found a risk of 2.4% in pts with ESRD)

Enhancing Renal Mass In general, any mass that enhances by more than 15 Hounsfield units should be considered RCC until proven otherwise and warrants referral to a urologist

MRI Enhancement

Epidemiology About 64,000 new cases of kidney cancer will occur in 2017 40,610 in men and 23,380 in women About 14,400 people (9,470 men and 4,930 women) will die from this disease Kidney cancer is among the 10 most common cancers in men and women Lifetime risk for developing kidney cancer is about 1 in 63 (1.6%). This risk is higher in men than in women. Rate of new kidney cancers has been rising since the 1990s, although this seems to have leveled off in the past few years. Part of this rise was probably due to the use of newer imaging tests such as CT scans, which picked up some cancers that might never have been found otherwise. The death rates for these cancers have gone down slightly since the middle of the 1990s. Median age at diagnosis is 64 years

Epidemiology, continued RCC is the most lethal of the urologic cancers Traditionally, ~40% of patients with RCC ultimately die of their disease. Stage dependent (97%-8%) The increased incidence in RCC is largely due to detection of small, localized tumors 85% of RCC’s are clear cell, followed by papillary, chromophobe and collecting duct tumors

Risk Factors Most commonly cited environmental risk factor is tobacco exposure, with a relative risk of 1.4-2.5 compared with controls Multiple studies have also shown that RCC is more common among the obese, those with low socioeconomic standing and an urban background Causative factors have not been identified Other suggested etiologic factors include viruses, lead compounds, aromatic hydrocarbons, contrast agents, radiation and anti-hypertensive medications Moderate alcohol, fruit and vegetables and fatty fish consumption may reduce risk of RCC

Risk Factors, continued Male-to-female predominance of 3:2 Incidence is 10-20 percent higher in African Americans Incidence is higher in those with a history of Wilms’ tumor, acquired renal cystic disease and in those with end-stage renal failure Relative risk of 2.9 for individuals with a first- or second-degree relative with RCC The study of several hereditary types of RCC, including von Hippel- Lindau disease (VHL), has led to significant advances in the understanding of the molecular genetics of RCC

Presentation Classic triad of flank pain, gross hematuria and a palpable abdominal mass is now rare Incidental detection accounts for more than 50% of RCC cases Usually organ confined with improved prognosis Signs of metastatic disease may include bone pain, adenopathy, or hemoptysis Paraneoplastic syndromes are found in 20% of patients, most commonly hypertension, anemia and hypercalcemia, hepatic dysfunction

Initial Evaluation A thorough physical examination should be performed with special attention to detecting supraclavicular adenopathy, an abdominal mass, lower extremity edema, a varicocele or subcutaneous nodules Laboratory evaluation includes a CBC, comprehensive metabolic panel, coagulation profile and urinalysis Imaging: CT/MRI

Renal Mass Biopsy 20-25% of clinical stage 1 renal masses are benign; if < 1cm 46% benign (Frank, J Urology 2003) Biology of renal masses are heterogeneous Traditionally served a limited role due to high false neg rate Used for suspected renal mets, abscess or lymphoma False neg rate now improved with rare cases of needle tract seeding 10-15% still indeterminate

Primary Treatment of Localized Disease Surgical resection remains the gold standard therapy for clinically localized RCC Radical nephrectomy includes resection of the kidney, perirenal fat within Gerota’s fascia, regional lymph nodes and the ipsilateral adrenal gland Can be performed either open or laparoscopically Adrenal gland can generally be spared if it appears normal on imaging

Nephron-Sparing Surgery Nephron-sparing surgery (NSS) was originally indicated only in clinical settings in which a radical nephrectomy would render the patient anephric Multiple studies have now shown that NSS has equivalent outcomes to radical nephrectomy when used for tumors up to 7 cm in greatest diameter Relative indications for NSS have now been expanded to include those patients with bilateral RCC, familial RCC, CRI, severe HTN or DM, reflux or hydronephrosis in the contralateral kidney, or those with tumors ≤4-5 cm and a preference for NSS

TNM Staging T1 ◦ T1a: tumor confined to kidney, <4 cm T1b: tumor confined to kidney, >4 cm but <7 cm T2: limited to kidney >7 cm◦ T2a: tumor confined to kidney, >7 cm but not >10 cm T2b: tumor confined to kidney, >10 cm T3: tumor extension into major veins or perinephric tissues, but not into ipsilateral adrenal gland or beyond Gerota's fascia ◦ T3a: Tumor grossly extends into the renal vein or its segmental (muscle-containing) branches, or tumor invades perirenal and/or renal sinus fat but not beyond the Gerota fascia T3b: spread to infra diaphragmatic IVC T3c: spread to supra diaphragmatic IVC or invades the wall of the IVC T4: involves ipsilateral adrenal gland or invades beyond Gerota's fascia

T1a Case courtesy of Dr Ahmed Abd Rabou, Radiopaedia.org, rID: 50396

T1b Case courtesy of Dr Roberto Schubert, Radiopaedia.org, rID: 14439

T2 Case courtesy of Dr Ian Bickle, rID: 26207

Nephron-Sparing Surgery NSS can be performed either open or laparoscopically Robotic assistance now more frequently used to more accurately excise renal tumors while decreasing ischemia time and blood loss

Other Treatment Options Cryoablation and radiofrequency ablation have gained acceptance as treatment options for small renal masses, especially in patients of advanced age or those with significant comorbidities that may not tolerate conventional surgery Both can be performed percutaneously or laparoscopically Long-term follow-up remains limited at this time, but most series report low rates of local recurrence, although some patients have required repeated treatments Surveillance has also emerged as a reasonable option for patients with small (<3 cm) renal masses who are elderly or poor surgical candidates Multiple studies have demonstrated an average growth rate of 3-4 mm per year and progression to metastatic disease in 1% or less after several years of follow-up Not generally considered appropriate for masses larger than 3 cm, poorly marginated tumors, or for younger patients who are able to tolerate treatment

Outcomes after Surgery Estimated 5-year survival rates for surgically treated localized RCC is 96% for stage I disease and 82% for stage II disease Prognostic factors include tumor grade, stage, presence of regional nodal involvement, and evidence of metastatic disease at presentation

Treatment Outcomes Approximately 1/3 of patients who undergo resection will have a recurrence Most common site of distant recurrence is the lung and median time to relapse is 1-2 years This has led to guidelines and recommendations for continued surveillance with periodic bloodwork, chest imaging and CTs following treatment Recent evidence suggests that follow-up for small tumors (<4 cm) may safely be stopped after several years

Other Solid Renal Masses The most common benign solid renal lesion is oncocytoma Solid masses with identifiable areas of fat density are classified as angiomyolipomas Solid renal masses may also represent metastatic disease or lymphoma (biopsy appropriate

Angiomyolipoma

Epidemiology of Renal Angiomyolipoma The prevalence in autopsies is 0.3%, with ultrasound screening 0.1%. Women are much more frequently affected than men. Age peak 50– 60 years. 45–80% of patients with tuberous sclerosis have (bilateral) asymptomatic angiomyolipomas. In tuberous sclerosis, there is an equal distribution between men and women, age peak 30 years. Signs & Symptoms Flank pain Potentially life-threatening hemorrhage due to spontaneous rupture into the retroperitoneum (Wunderlich's syndrome) Pregnancy increases the risk of rupture.

Diagnosis of Renal Angiomyolipoma Sonography of the Kidney: Sonography of the kidneys shows an echogenic mass in the kidney, caused by the high fat content. CT-Abdomen: The fat content typically causes a hypodense mass in the kidney with -20 to -80 HU, this enables the differentiation to renal cell carcinoma Calcifications are rare in renal angiomyolipoma. MRI and Angiography useful as well

Angiomyolipoma CT Case courtesy of Dr Abdallah Khateeb, rID: 44940

Renal Angiomyolipoma Treatment Conservative Treatment: Annual imaging controls are possible with angiomyolipomas less than 4 cm and mild symptoms. The annual growth rate is about 5%, in tuberous sclerosis up to 20%. Partial Nephrectomy: indicated in angiomyolipomas of >4 cm, severe symptoms or in tumors of uncertain diagnosis. Selective embolization: possible minimally invasive treatment option. Sometimes, a relapse is possible after embolization. Rarely, percutaneous drainage of necrosis is necessary. Emergency nephrectomy: necessary in rupture of angiomyolipoma with life- threatening bleeding.

Renal Cysts

Campbell-Walsh Urology, Tenth Edition

Case courtesy of Dr. David Cueta, rID: 274479 Case courtesy of Dr. Ian Bickle, rID: 21139

Bosniak II Case courtesy of Dr Ian Bickle, Radiopaedia.org, rID: 21712

Bosniak IIf Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 23385 Case courtesy of Dr Usman Bashir, Radiopaedia.org, rID: 18823

Bosniak III Slideplayer.com

Bosniak IV Case courtesy of Dr Andrew Dixon, Radiopaedia.org, rID: 23402

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