Dr Briony Scott, wife of ABC boss Mark Scott, diagnosed with lung cancer

Dr Briony Scott, the principal of Sydney private school Wenona and the wife of ABC boss Mark Scott, has been diagnosed with lung cancer.

Dr Scott informed parents and staff in a letter today that she had to undergo immediate treatment after receiving the news, reports the Sydney Morning Herald.

In the letter, Dr Scott said she had never smoked and it was "just one of those things".

"I am full to the brim of hope and have witnessed countless examples in our own community of both girls and parents who have faced similar challenges, with courage and humour," she wrote.

Dr Scott also announced that she would be on leave for the rest of 2015 and is expected to return early next year.

She has been the principal of the north shore boarding school since July 2011, and holds a PhD from the University of Sydney in education.

She is the wife of the ABC managing director, Mark Scott, who has held the top job there since 2006.