Joan Rivers Dr. Gwen Korovin Surfaces Mum on Selfie Allegation

9/18/2014 9:40 AM PDT

Joan Rivers' personal ENT who was performing a procedure on the comedienne when she stopped breathing was seen for the first time in NYC Thursday ... and she clearly didn't want to talk.

An independent photog asked Dr. Gwen Korovin if she took a selfie while performing a biopsy on Joan ... but she was having none of it as she entered her office building.

TMZ broke the story ... Dr. Korovin is the ENT Joan brought in for the procedure. Dr. Korovin's other celebrity patients include Celine Dion, Lady Gaga, John Mayer and Hugh Jackman.