Currently, cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) is known as the best option for diagnosing<unk><unk>  tumors. Unenhanced (left) and nephrographic phase (right) CT scans display a 1-cm low-attenuation<unk>  tumor (arrow) in the right<unk>  cortex Computed tomography (CT) Contrast-enhanced computed tomography (CT) is most commonly used to identify the subtypes of RCC.<unk>  can be differentiated from other types of RCC due to its distinguishing features, displaying a small hypovascular<unk>  tumor on T2 weighted images. Typically,<unk>  tends to appear homogeneous while clear cell RCC is likely to be in a heterogeneous form when the tumor is less than 3 cm in diameter. Comparatively, in cases of tumors larger than 3 cm in diameter,<unk>  is generally heterogeneous with areas of necrosis and hemorrhage compared to chromophobe RCC. Solid, small<unk>  tumors (<3 cm in diameter) are more easily viewed on nephrographic, excretory phase images rather than on unenhanced, corticomedullary phase images. Magnetic resonance imaging (MRI) Magnetic resonance imaging (MRI) is recommended instead of CT for patients with an allergy to iodinated contrast materials. As some<unk>  tumors do not enhance significantly on CT, MRI examination is required to be performed with more sensitive contrast enhancement. On MRI, the distinct features of<unk>  are fibrous capsules and homogeneously low single intensity on both T1- and T2-weighted images. Specifically,<unk>  exhibits hypointensity due to its dense collagenous matrix or deposition of calcium and hemosiderin within the tumor. Such visual features help<unk>  to be differentiated from clear cell RCC, which has heterogeneously higher single intensity shown on T2-weighted images.<unk>  displays the smallest tumor-to-cortex enhancement at corticomedullary and nephrographic phases when juxtaposed with clear cell and chromophobe RCCs. Grading System<unk>  type 1, grade 2: Nucleoli (one annotated by arrows) are conspicuous and eosinophilic at 400 magnification and visible but not prominent at 100 magnification. The WHO/ISUP system is histological tumor grading system for<unk>  cell<unk> , suggested by the International Society of Urologic Pathologists (ISUP) in 2012 to diagnose tumor grades based on nucleolar prominence. Currently recommended by the WHO, this four-tiered WHO/ISUP grading system has also been validated for<unk> . +WHO/ISUP system for<unk>  <unk>  Grading Grade Definition 1 Nucleoli are absent or inconspicuous and basophilic at 400 magnification. 2 Nucloeli are conspicuous and eosinophilic at 400 magnification and visible but not prominent at 100 magnification. 3 Nucleoli are conspicuous and eosinophilic at 100 magnification 4 There is extreme nuclear pleomorphism, multinucleate giants cells, and/or rhabdoid an/or sarcomatoid differentiation Earlier, the Fuhrman system was largely used, and was similarly based on nuclear features.
Papillary renal cell carcinoma
Renal medullary carcinoma
Renal anaplastic sarcoma
Renal medullary fibroma
Renal oncocytoma
Clear cell renal cell carcinoma
Clear cell papillary renal cell carcinoma
Renal cell carcinoma