Diagnostic Ultrasound - Abdomen and Pelvis

Renal Cell Carcinoma
Diagnoses: Urinary Tract
Renal Oncocytoma
• No imaging criteria to accurately differentiate from RCC
Renal Metastases and Lymphoma
• Metastases: Usually hypovascular; infiltrative or multiple
• Lymphoma:Usually multiple or bilateral; hypovascular solid
masses, typically associated with lymphadenopathy
Column of Bertin
• Isoechoic; located in mid 1/3 of kidney
Multilocular Cystic Nephroma
• Morphologically indistinguishable from cystic RCC but
different demographics
Complex Renal Cyst
• Septated cyst ± calcification ± internal hemorrhage or high
density ± thick wall
Renal Abscess
• Renal enlargement with complex cystic mass
• Differentiated by clinical history and urinalysis
PATHOLOGY
General Features
• Etiology
○ Risk factors:Most sporadic but can be hereditary (~ 4%)
– Genetics: von Hippel-Lindau (VHL) disease, hereditary
papillary RCC, Birt-Hogg-Dubé syndrome, tuberous
sclerosis, sickle cell trait
– Advanced age
– Long-term dialysis/acquired cystic renal
disease,kidney transplantation
– Environmental/chemical: Smoking, obesity,
diethylstilbestrol, lead, cadmium, diuretic use, HIV
infection
Staging, Grading, & Classification
• TNM classification system of RCC (American Joint
Committee on Cancer, 2002)
• Fuhrman (nuclear) grade: Most common system for grading
RCC, based on appearance of nuclei (uniform to bizarre)
and presence of nucleoli
Gross Pathologic & Surgical Features
• Completely solid to cystic mass with irregular, lobulated
margins
• Heterogeneous appearance with hemorrhage and necrosis
Microscopic Features
• Clear cell RCC: Cells with clear cytoplasm from high
glycogen and lipid content
• Papillary RCC: Small cells with scant cytoplasm arranged in
papillae
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Gross hematuria (60%), flank pain (40%), palpable flank
mass (30-40%); classical triad (< 10%)
○ Fever, anorexia, weight loss, malaise, nausea, vomiting
○ Most tumors now detected incidentally and are smaller
• Other signs/symptoms
○ Varicocele formation (tumor thrombus in left renal vein
or IVC)
○ Hypertension, hepatopathy (Stauffer syndrome),
paraneoplastic syndromes (hypercalcemia or
polycythemia)
○ 30% present with symptomatic metastases
Demographics
• Age
○ 50-70 years of age
• Gender
○ M:F = 2:1, slightly higher in African Americans
• Epidemiology
○ 8th most common malignancy affecting adults, most
common primary renal malignancy
○ 3-4% of all cancers
○ 24-45% of VHL patients develop RCC, which are
multifocal and bilateral
Natural History & Prognosis
• Prognosis: 5-year survival rate (SR): Stage I: 96%; stage II:
82%; stage III: 64%; stage IV: 23%
• Larger tumors, bilateral or multiple RCCs have poorer SR
• Clear cell RCCs have greatest metastatic potential and
chromophobe tumors have best overall prognosis
• Metastases: Lungs most common; lymph nodes, bones,
liver, brain, adrenal glands, or pancreas
• Tumor may recur locally or in contralateral kidney
Treatment
• Radical or partial nephrectomy (equally as efficacious)
○ Indications for partial nephrectomy include ≤ 4 cm size,
peripheral location, exophytic extension, no invasion of
vessels or lymph nodes
• Radiofrequency ablation and cryoablation
DIAGNOSTIC CHECKLIST
Consider
• Suspect RCC in solid renal lesions with internal vascularity or
calcifications
Image Interpretation Pearls
• Evaluate complex cystic lesions for solid nodules and
internal color flow
○ CECT and enhanced MR for lesion characterization and
staging
SELECTED REFERENCES
1. Allen BC et al: Characterizing solid renal neoplasms with MRI in adults.
Abdom Imaging. 39(2):358-87, 2014
2. Kang SK et al: Solid renal masses: what the numbers tell us. AJR Am J
Roentgenol. 202(6):1196-206, 2014
3. Klatte T et al: The contemporary role of ablative treatment approaches in
the management of renal cell carcinoma (RCC): focus on radiofrequency
ablation (RFA), high-intensity focused ultrasound (HIFU), and cryoablation.
World J Urol. 32(3):597-605, 2014
4. Patel U et al: Imaging in the follow-up of renal cell carcinoma. AJR Am J
Roentgenol. 198(6):1266-76, 2012
5. Ng CS et al: Renal cell carcinoma: diagnosis, staging, and surveillance. AJR
Am J Roentgenol. 191(4):1220-32, 2008
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