|Micrograph of a renal oncocytoma, a type of benign kidney tumour. H&E stain.|
|Classification and external resources|
Kidney tumours may be discovered on medical imaging incidentally (i.e. an incidentaloma), or may be present in patients as an abdominal mass or kidney cyst, hematuria, abdominal pain, or manifest first in a paraneoplastic syndrome that seems unrelated to the kidney.
There are many forms of kidney tumours:
- The most frequent, malignant, primary kidney cancer is renal cell carcinoma (RCC) - which has several subtypes:
- Clear cell RCC.
- Papillary RCC
- Chromophobe RCC
- Collecting duct RCC
- Mesoblastic nephroma, a congenital tumor of the kidney's mesenchyme (i.e. connective tissue cells) detected prenatally or, more typically, during the first <4 years of life.
- Metastatic tumour, e.g. ovarian carcinoma.
|Component||1 point||2 points||3 points|
|R (radius, maximal diameter)||≤ 4 cm||> 4 and < 7 cm||≥ 7 cm|
|E (exophytic/endophytic)||≥ 50% exophytic||< 50% exophytic||Completely endophytic|
|N (nearness to collecting system/renal sinus)||≥ 7 mm||> 4 and < 7 mm||≤ 4 mm|
|A (anterior/posterior locator)||A descriptor of “a,” “p,” or “x” is assigned for tumour location.|
|L (location relative to polar lines)||Entirely below lower polar or above upper polar line||Mass crosses polar line||50% of the mass is across polar line, or
mass is entirely between polar lines, or
mass crosses axial midline
A higher score indicates a higher difficulty in removing the tumor surgically, potentially making nephrectomy necessary.
- Gill IS, Aron M, Gervais DA, Jewett MA (February 2010). "Small renal mass". N. Engl. J. Med. 362 (7): 624–34. doi:10.1056/NEJMcp0910041. PMID 20164486.
- Gooskens SL, Houwing ME, Vujanic GM, Dome JS, Diertens T, Coulomb-l'Herminé A, Godzinski J, Pritchard-Jones K, Graf N, van den Heuvel-Eibrink MM (2017). "Congenital mesoblastic nephroma 50 years after its recognition: A narrative review". Pediatric Blood & Cancer. 64 (7). doi:10.1002/pbc.26437. PMID 28124468.
- Parsons, Rosaleen B.; Canter, Daniel; Kutikov, Alexander; Uzzo, Robert G. (2012). "RENAL Nephrometry Scoring System: The Radiologist's Perspective". American Journal of Roentgenology. 199 (3): W355–W359. doi:10.2214/AJR.11.8355. ISSN 0361-803X.