Editing Collecting duct system (section)

==Collecting duct carcinoma==
{{Main|Collecting duct carcinoma}}
Carcinoma of the collecting duct is a relatively rare subtype of renal cell carcinoma (RCC), accounting for less than 1% of all RCCs.<ref>Kennedy ''et al.'', 1990{{full citation needed|date=April 2014}}</ref><ref>Rumpelt ''et al.'', 1991{{full citation needed|date=April 2014}}</ref> Many reported cases have occurred in younger patients, often in the third, fourth, or fifth decade of life.<ref name="ReferenceA">Carter ''et al.'', 1992{{full citation needed|date=April 2014}}</ref> Collecting duct carcinomas are derived from the medulla, but many are infiltrative, and extension into the cortex is common.<ref>Pickhardt ''et al.'', 2001{{full citation needed|date=April 2014}}</ref> 
Most reported cases have been high grade and advanced stage and have not responded to conventional therapies.<ref name="ReferenceA"/><ref>Chao ''et al.'', 2002b{{full citation needed|date=April 2014}}</ref> 
Most patients are symptomatic at presentation.<ref name="ReferenceB">Tokuda ''et al.'', 2004{{full citation needed|date=April 2014}}</ref> Immunohistochemical and molecular analyses suggest that collecting duct RCC may resemble transitional cell carcinoma, and some patients with advanced collecting duct RCC have responded to cisplatin- or gemcitabine-based chemotherapy.<ref>Milowsky ''et al.'', 2002{{full citation needed|date=April 2014}}</ref><ref>Peyromaure ''et al.'', 2003{{full citation needed|date=April 2014}}</ref>