ER star to have breast tumour op

Maura Tierney was nominated for an Emmy for her long-standing role

ER star Maura Tierney is to undergo surgery to remove a breast tumour, she has confirmed in a statement.

The 44-year-old actress, who appeared in 10 series of the medical drama, said she has been assured that her condition is "very treatable".

Production on her new television show Parenthood has been halted to allow Tierney to receive treatment.

The actress, who was Emmy-nominated for playing Dr Abby Lockhart, has also appeared in Jim Carrey film Liar Liar.

"I have discovered a tumour in my breast which requires surgery," Tierney said in a statement.

"I will not know either my exact diagnosis or course of treatment until that surgery is performed. I'm very optimistic as to the outcome."

The actress added that she was looking forward to going back to work.

She said that NBC - who are producing Parenthood - had caused "confusion and undue alarm" by announcing that filming had been delayed.