title: Case Report: Multifocal biphasic squamoid alveolar renal cell carcinoma.
abstract: A multifocal biphasic squamoid alveolar renal cell carcinoma in a 68-year-old man is reported. Four different peripheral tumor nodules were identified on gross examination. A fifth central tumor corresponded to a conventional clear cell renal cell carcinoma. Biphasic squamoid alveolar renal cell carcinoma is a rare tumor that has been very recently characterized as a distinct histotype within the spectrum of papillary renal cell carcinoma. Immunostaining with cyclin D1 seems to be specific of this tumor subtype. This is the first reported case with multifocal presentation.
authors.affiliation: Department of Pathology, Cruces University Hospital, Biocruces Health Research Institute, University of the Basque Country (UPV/EHU), Barakaldo, Spain.
authors.forename: Jose Ignacio
authors.initials: JI
authors.lastname: Lopez
keywords: Kidney; biphasic squamoid alveolar renal cell carcinoma; immunohistochemistry; papillary renal cell carcinoma