The University of Pennsylvania is keeping mum on the resignation of a dean of its graduate school, who duped the Ivy League school into believing he had a doctoral degree from Columbia University.

A report this week by the Philadelphia Inquirer raised questions about the pedigree of Doug Lynch, vice dean of the graduate school of education, who claimed to have received a master's degree and a doctorate from Columbia University in 2005 and 2007, respectively.

Neither of those claims is true, according to Columbia officials. Lynch did received a master's degree in 2010, and has entered -- but not yet completed -- the doctoral program.