Clear cell Ca arises from the proximal tubular cells. On gross examination it's a solitary unilateral lesion usually with a pseudocapsule. On microscopic examination the tumour cells are clear and contain glycogen and lipids. Most are well differentiated. Papillary Ca arises from the DCT. It may be multifocal or bilateral. Typically they are hemorrhagic and cystic and composed of cuboidal or low columnar cells. Chromophobe Ca arises from intercalated cells of collecting duct and the tumour cells are pale eosinophilic often with perinuclear halo. Ref: Robbin's illustrated, 7th Edition, Page 1016, 1017