Uncommon and recently described renal carcinomas

Abstract

Major consensus conferences held over a decade ago laid the foundations for the current (2004) WHO classification of renal carcinoma. Clear cell, papillary and chromophobe carcinomas account for 85-90% carcinomas seen in routine practice. The remaining 10-15% of carcinomas consist of rare sporadic and hereditary tumors, some of which had been long recognized, but many of which only emerged as distinct entities in the decade leading up to the WHO publication. Collecting-duct carcinoma is a rare, often lethal form of carcinoma. Medullary carcinoma associated with sickle cell trait, has emerged as a distinctive tumor showing some overlapping features with upper tract urothelial carcinoma. Mucinous tubular and spindle-cell carcinoma and tubulocystic carcinoma were earlier considered as patterns of low-grade collecting-duct carcinoma, but are now recognized as separate tumor entities. Carcinomas associated with somatic translocations of TFE3 and TFEB comprise a significant proportion of pediatric renal carcinomas. Oncocytoid renal carcinomas in neuroblastoma survivors was recognized as a unique tumor category in the WHO classification. Renal carcinoma associated with end-stage renal disease is now recognized as having distinct morphological patterns and behavior. In addition there is a group of rare recently described carcinomas, including clear cell papillary carcinoma, oncocytic papillary renal cell carcinoma, follicular renal carcinoma and leiomyomatous renal cell carcinoma. It behooves the surgical pathologist to not only be capable of diagnosing the common forms of renal cancer, but also to be aware of the rare types of renal carcinoma, many of which have emerged in recent years.

Canadian guideline on genetic screening for hereditary renal cell cancers

“…17 Uncommon and new emerging entities of RCC may also represent sources of hereditary cases. 18 The benefit of identifying hereditary RCC is to inform the medical management of affected individuals. As well, the identification of a single affected family member frequently leads to the diagnosis of a hereditary predisposition in other asymptomatic family members; surveillance can then be offered to these family members before any cancer develops.…”

Review of tubulocystic carcinoma of the kidney with focus on clinical and pathobiological aspects

“…Most TCKs are discovered incidentally and are typically small in size (almost 40% are smaller than 2 cm) [3,13,14]. However, some patients are symptomatic and may present with abdominal pain, abdominal distention and hematuria [15]. Radiologically, TCK may demonstrate Bosniak type II, type III or even type IV.…”

“…Radiologically, TCK may demonstrate Bosniak type II, type III or even type IV. Hence, this disease may pose a serious challenge in differential diagnosis and clinical management [6,11,15]. The radiological features of TCK overlap with other benign or malignant lesions including cystic nephroma (CN), mixed epithelial and stromal tumor (MEST), renal oncocytoma (RO) with tubulocystic pattern, multilocular cystic RCC and renal carcinoma associated with Xp11.2 translocations/TFE3 gene fusions (Xp11.2 RCC).…”

Multistep regulation of TFEB by MTORC1

“…[1][2][3] In these tumors, the TFEB gene is translocated and overexpressed. TFEB is a bHLH (basic helix-loop-helix) leucine zipper transcription factor of the MITF family.…”