Typically, PRCC 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, PRCC is generally heterogeneous with areas of necrosis and hemorrhage compared to chromophobe RCC. Solid, small PRCC 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 renal 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 PRCC are fibrous capsules and homogeneously low single intensity on both T1- and T2-weighted images. Specifically, PRCC exhibits hypointensity due to its dense collagenous matrix or deposition of calcium and hemosiderin within the tumor. Such visual features help PRCC to be differentiated from clear cell RCC, which has heterogeneously higher single intensity shown on T2-weighted images. PRCC displays the smallest tumor-to-cortex enhancement at corticomedullary and nephrographic phases when juxtaposed with clear cell and chromophobe RCCs. Grading System
The WHO/ISUP system is histological tumor grading system for renal cell carcinoma, 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 PRCC.
The FDA granted the approval of Nulibry to Origin Biosciences, Inc., in February 2021. Society and culture
Legal status
On 21 July 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization under exceptional circumstances for the medicinal product Nulibry, intended for the treatment of patients with molybdenum cofactor deficiency (MoCD) Type A. The applicant for this medicinal product is Comharsa Life Sciences Ltd. Fosdenopterin was approved for medical use in the European Union in September 2022. References
External links
"Fosdenopterin". Drug Information Portal. U.S. National Library of Medicine.