F1000Research Open Peer Review , AOUI Verona Italy, Guido Martignoni , University of Verona Italy Anna Calió , Jose Luis Rodriguez-Peralto Complutense University of Madrid Spain , Vita-Salute San Claudio Doglioni Raffaele University Italy Discuss this article (0) Comments 3 2 1 CASE REPORT Case Report: Multifocal biphasic squamoid alveolar renal cell carcinoma [version 2; referees: 3 approved] José I. López Department of Pathology, Cruces University Hospital, Biocruces Health Research Institute, University of the Basque Country (UPV/EHU), Barakaldo, Spain 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. José I. López ( ) Corresponding author: joseignacio.lopez@osakidetza.eus López JI. How to cite this article: Case Report: Multifocal biphasic squamoid alveolar renal cell carcinoma [version 2; referees: 3 2016, :607 (doi: ) approved] F1000Research 5 10.12688/f1000research.8451.2 © 2016 López JI. This is an open access article distributed under the terms of the , which Copyright: Creative Commons Attribution Licence permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The author(s) declared that no grants were involved in supporting this work. Grant information: Competing interests: No competing interests were disclosed. 08 Apr 2016, :607 (doi: ) First published: 5 10.12688/f1000research.8451.1 Referee Status: Invited Referees version 2 published 24 May 2016 version 1 published 08 Apr 2016 1 2 3 report report report report 08 Apr 2016, :607 (doi: ) First published: 5 10.12688/f1000research.8451.1 24 May 2016, :607 (doi: ) Latest published: 5 10.12688/f1000research.8451.2 v2 Page 1 of 7 F1000Research 2016, 5:607 Last updated: 25 DEC 2016