Though renal cell carcinoma (RCC) accounts for 2% of global cancer diagnoses and deaths, it has more than doubled in incidence in the developed world over the past half-century, and today is the ninth most common neoplasm in the United States (US). While North America and Western Europe have the highest disease burden (with the Belarus highest in incidence), Latin America, Asia and Africa are projected to see an increase in incidence as nation's transition to a Western lifestyle. Most cases of RCC are discovered incidentally on imaging, and survival is highly dependent on the stage at diagnosis, with the metastatic disease having only a 12% 5-year survival rate. Two-thirds of RCC diagnoses are made in men, and the average age of diagnosis in the US is 64. Those with genetic predispositions, namely von Hippel-Lindau disease, tend to be diagnosed 20 years earlier. RCC has a greater incidence among Hispanics and Native Americans, and a lower survival rate among African Americans in the US. Modifiable risk factors for RCC include smoking, obesity, poorly-controlled hypertension, diet and alcohol, and occupational exposures. Prevention strategies aimed at improving survival and reducing disparities include addressing lifestyle factors and access to regular healthcare among underserved populations and in developing nations, as well as more rigorous imaging guidelines to detect RCC at an earlier stage. A stronger understanding of global RCC epidemiology can facilitate prevention efforts, especially in developing nations and underserved communities where disease burden is predicted to rise in the coming decades.

/pdf/epidemiology-of-renal-cell-carcinoma-3c1nmnn1bo.pdf

Epidemiology of renal cell carcinoma

Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes.

/pdf/renal-cell-carcinoma-histological-classification-and-2neity9dxf.pdf

Renal cell carcinoma: histological classification and correlation with imaging findings

OBJECTIVE. The objective of our study was to assess the value of diffusion-weighted imaging in differentiating among the various subgroups of renal masses.MATERIALS AND METHODS. This retrospective study measured the apparent diffusion coefficients (ADCs) of renal masses. Malignant lesions were confirmed with surgical pathology results. Benign cystic lesions were stable without treatment for a minimum follow-up of 24 months.RESULTS. There were 20 and 22 patients, respectively, with benign lesions (three abscess, 31 cysts) and malignant lesions (17 clear cell, five papillary, one chromophobe, and two transitional cell cancers). The malignant lesions were larger than the benign lesions (mean diameter, 4.2 vs 2.6 cm, respectively; p = 0.01, Student's t test). The ADC values of the benign lesions were significantly higher than those of the malignant lesions (mean, 2.72 vs 1.88 × 10–3 mm2/s; p < 0.0001). The ADCs of the 31 benign cysts were significantly higher than those of the seven cystic renal cancers (2.77...

https://www.ajronline.org/doi/pdfplus/10.2214/AJR.09.3024

Usefulness of diffusion-weighted imaging in the evaluation of renal masses.

Multiparametric MRI of solid renal masses: pearls and pitfalls

Representing 2%-3% of adult cancers, renal cell carcinoma (RCC) accounts for 90% of renal malignancies and is the most lethal neoplasm of the urologic system. Over the last 65 years, the incidence of RCC has increased at a rate of 2% per year. The increased incidence is at least partly due to improved tumor detection secondary to greater availability of high-resolution cross-sectional imaging modalities over the last few decades. Most RCCs are asymptomatic at discovery and are detected as unexpected findings on imaging performed for unrelated clinical indications. The 2004 World Health Organization Classification of adult renal tumors stratifies RCC into several distinct histologic subtypes of which clear cell, papillary and chromophobe tumors account for 70%, 10%-15%, and 5%, respectively. Knowledge of the RCC subtype is important because the various subtypes are associated with different biologic behavior, prognosis and treatment options. Furthermore, the common RCC subtypes can often be discriminated non-invasively based on gross morphologic imaging appearances, signal intensity on T2-weighted magnetic resonance images, and the degree of tumor enhancement on dynamic contrast-enhanced computed tomography or magnetic resonance imaging examinations. In this article, we review the incidence and survival data, risk factors, clinical and biochemical findings, imaging findings, staging, differential diagnosis, management options and post-treatment follow-up of RCC, with attention focused on the common subtypes.

Review of renal cell carcinoma and its common subtypes in radiology.

Renal cell carcinoma (RCC) is a cause of significant morbidity and mortality, with an estimated 35,000 new cases and 12,480 deaths in the United States in 2003. Recent advances in imaging technology, pathology, urology, and oncology permit early diagnosis of RCC and facilitate optimal management. The 2004 World Health Organization classification for renal neoplasms recognizes several distinct histologic subtypes of RCC. These subtypes include clear cell RCC, papillary RCC, chromophobe RCC, hereditary cancer syndromes, multilocular cystic RCC, collecting duct carcinoma, medullary carcinoma, mucinous tubular and spindle cell carcinoma, neuroblastoma-associated RCC, Xp11.2 translocation-TFE3 carcinoma, and unclassified lesions. Different histologic subtypes of RCC have characteristic histomorphologic and biologic profiles. Clear cell RCC is the most common subtype and has a less favorable prognosis (stage for stage) than do papillary RCC and chromophobe RCC. Collecting duct carcinoma and renal medullary carcinoma are associated with aggressive clinical behavior and a poor prognosis.

Arthur D. Cortez

Papers

Common and Uncommon Histologic Subtypes of Renal Cell Carcinoma: Imaging Spectrum with Pathologic Correlation