Evolving classification of renal cell neoplasia

Abstract

The development of consensus classifications for renal epithelial neoplasia in 1996 and 1997 led to the recognition of renal adenoma, renal oncocytoma and metanephric adenoma/adenofibroma as benign tumors and conventional (clear cell) renal cell carcinoma (RCC), papillary RCC, chromophobe RCC and collecting duct carcinoma as malignant morphotypes. While the overwhelming majority of renal adenomas and metanephric adenomas are benign, malignant transformation of both types have been described and genetic predictors of malignant transformation are as yet unknown. The main groups of malignant renal tumors are associated with characteristic genetic changes; conventional RCC (-3p), papillary RCC (+7, +17, -Y), chromophobe RCC (hypodiploid). Recent studies have also shown focal loss of heterozygosity of 3p segments in papillary and chromophobe RCC, indicating that 3p mutations are not confined to the conventional RCC morphotype and suggesting the presence of an important tumor suppressor gene at this site. Sarcomatoid metaplasia may occur in any morphotype and this is associated with a poor prognosis. More recently additional varieties of conventional RCC (multilocular cystic RCC), collecting duct carcinoma (medullary renal carcinoma) and papillary RCC (Types 1 and 2), each showing a characteristic morphology, have been recognized.

Renal medullary carcinomas: histopathologic phenotype associated with diverse genotypes

“…Hybrid oncocytic and clear cell renal tumors characterize Birt-Hogg-Dube syndrome (BHD) caused by a germ line mutation in the folliculin gene on chromosome 17p11.2. Xp11 translocation RCC is a group of neoplasms characterized by translocations involving a breakpoint at Xp11.2 [6][7][8][9][10]. Hereditary leiomyomatosis with RCC (HLRCC) is an autosomal dominant tumor syndrome caused by a germ line mutation in fumarate hydratase (FH) gene on chromosome 1q42.…”

Morphologic and Molecular Charecteristics of Renal Tumors

“…Olgularda 11 yaşa inen erken tümörler tanımlanmıştır. Bu nedenle mutasyonlu olgularda 20 yaş sonrasında önerilen tarama 10 yaştan itibaren ultrason, 16-18 yaş sonrası ultrason ve manyetik rezonans görüntüleme olarak değiştirilmiştir (2,3,40,41).…”

“…Makroskopik olarak 1826'lara dayanan böbrek tümörlerinin sınıflandırma süreci morfolojik, moleküler ve genetik değerlendirmeler sürekli gelişmektedir. Dünya Sağlık Örgütü (DSÖ) 2004 sınıflandırmasından sonra 2012 Vancouver sınıflaması ile yeni alt tipler tanımlamaya alınmıştır (1,2,3). Sınıflamaya henüz alınmayan bazı alt tipler bulunmaktadır.…”

Rare histological subtypes of renal cell carcinoma in everyday diagnostic practice.

“…The classification of renal neoplasia is still based on morphology but it has been evolving dynamically over the past years due to advances in the understanding of molecular pathogenesis of these tumours [1]. Correct diagnosis of renal tumours carries significant clinical implications for patients such as prognostic risk stratification, selection of targeted therapeutics and identification of cases for further genetic testing [1][2][3].…”

“…The last WHO Classification of Tumours of the Urinary System and Male Genital Organs (2016) recognizes several distinct RCC subtypes. New tumour entities include: hereditary leiomyomatosis and renal cell carcinoma syndrome-associated renal cell carcinoma, Succinate dehydrogenase-deficient renal cell carcinoma, tubulocystic renal cell carcinoma, acquired cystic disease-associated renal cell carcinoma, and clear cell papillary renal cell carcinoma [1,[4][5]. In addition, the classification recognizes also tumour types described as emerging, which have distinct histological and genetic pattern but due to their rarity there is yet not enough data to include them as separate subtypes [1,[4][5].…”