Ole Petter Fraas CLAUSEN
Professor emeritus of Pathology, University of Oslo, Consultant of pathology, Oslo University Hospital, Norway

He graduated from the University of Graz Austria, and received his PhD from the University of Oslo. He has been professor of pathology at the university of Oslo since 1987 and is professor emeritus since 2014 at the same place. He is honorary member of the Norwegian Society of Pathology and has been leader of the Board of teachers in pathology at the University of Oslo for two decades.


His main research interests are within skin and gastrointestnal pathology, where he has contributed with genotypic and phenotypic studies of neoplastic development, as well as of prognosis of colonic and skin carcinomas. He has published more than 250 papers in scientific journals within these fields.


During the last two decades he and his coworkers has focused on studies of epidermal neoplastic development with main emphasis on keratoacanthomas, which are skin neoplasms with malignant morphology like infiltrative growth and cellular atypia. Nevertheless, these neoplasm will regress despite there malignant phenotype. We are currently studying the responsible mechanisms for regression, and what is distinguishing keratoacanthomas (KAs) from there malignant counterpart cutaneous squamous cell carcinomas (c SCCs).