AJR:204, May 2015 1031 medullary, and unclassified. Clear cell RCC is the most common histologic type, ac- counting for approximately 70–75% of RCCs [8, 10, 11]. Clear cells, which arise from the proximal convoluted tubular epithelium, are grossly yellow-tan owing to lipid content but appear clear after staining owing to their gly- cogen-rich content [8]. Granulosa and spin- dle cells may also be present in clear cell RCCs [8]. The vascular appearance of this cancer subtype is due to its characteristic network of small, thin-walled, sinusoidlike blood vessels [10, 11]. The multilocular cys- tic form of clear cell RCC consists of septat- ed, variably sized cysts lined by a monolayer of epithelial cells that contain serous or hem- orrhagic fluid [10, 11]. The papillary histologic subtype accounts for 10–15% of RCCs [10, 11]. Within these tumors, the papillae have fibrovascular cores with foamy macrophages and associated cholesterol crystals [11, 12]. Papillary RCCs are subclassified into two subtypes—baso- philic type I and eosinophilic type II [13]. These subtypes have similar clinical and his- topathologic patterns, except that type I has a substantially higher cancer-specific surviv- al rate than does type II [14–16]. This may be explained by the higher frequency of lym- phovascular invasion associated with type II papillary RCC [16]. Macroscopically, pap- illary RCCs exhibit hemorrhagic, necrotic, and cystic degeneration [10, 11]. The chromophobe subtype comprises ap- proximately 4–6% of RCCs [11]. Chromo- phobe cells are thought to arise from the in- tercalated cells of the collecting system [17]. Diagnostic Approach to Hereditary Renal Cell Carcinoma Shiva Gupta 1 Hyunseon C. Kang Dhakshina Moorthy Ganeshan Tharakeswara Kumar Bathala Vikas Kundra Gupta S, Kang HC, Ganeshan D, Bathala TK, Kundra V 1 All authors: Department of Diagnostic Radiology, University of Texas M. D. Anderson Cancer Center, Unit 1473, 1515 Holcombe Blvd, Houston, TX 77030. Address correspondence to S. Gupta (sgupta6@mdanderson.org). Genitourinary Imaging • Review AJR 2015; 204:1031–1041 0361–803X/15/2045–1031 © American Roentgen Ray Society R enal cell carcinoma (RCC) is the third most common urologic can- cer and accounts for 2–3% of adult malignancies [1, 2]. In the United States, incidence of kidney and renal pelvis cancer is on the rise, with an estimated 63,920 new cases and 13,860 new deaths by these cancers in 2014. [1, 3, 4]. Hereditary re- nal cancer syndromes account for approxi- mately 2–5% of RCCs [5–7]. The autosomal dominant inheritance in most of these syn- dromes results in a predisposition to the devel- opment of renal tumors [2, 5]. Several heredi- tary renal cancer syndromes occur equally in men and women, but some syndromes occur more often in women. These renal tumors tend to be multiple and distributed bilaterally and occur at a relatively young age [2]. Understanding the ontogeny, histopatho- genesis, and biologic behavior of these he- reditary RCCs has led to improvements in di- agnosis, treatment plans, and prognosis [8]. We provide an up-to-date discussion of these characteristics. We also introduce a pattern- based approach to the diagnosis of heredi- tary RCC syndromes that focuses on the pre- dominant histologic RCC subtype for each syndrome (adapting the Heidelberg classifi- cation of renal cell tumors [9]) and the asso- ciated renal and extrarenal imaging findings. Histopathologic Subtypes of Renal Cancers According to the 2004 World Health Or- ganization classification of renal tumors, his- tologic subtypes of RCC include clear cell, papillary, chromophobe, collecting duct, Keywords: chromophobe renal cell carcinoma, clear cell renal cell carcinoma, hereditary renal cell carcinoma syndromes, medullary renal cell carcinoma, papillary renal cell carcinoma, renal cell carcinoma DOI:10.2214/AJR.14.13514 Received July 18, 2014; accepted without revision August 20, 2014. Based on a presentation at the Radiological Society of North America 2013 annual meeting, Chicago, IL. OBJECTIVE. The purpose of this article is to discuss the histopathologic features, genet- ics, clinical presentation, and imaging of hereditary renal cancer syndromes. CONCLUSION. Hereditary renal cell carcinoma syndromes can be diagnosed with a pattern-based approach focused on the predominant histologic renal cell carcinoma subtype and associated renal and extrarenal features of each syndrome. Gupta et al. Hereditary Renal Cell Carcinoma Genitourinary Imaging Review Downloaded from www.ajronline.org by 52.73.204.196 on 05/16/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved