"Manisha will undergo a surgery on Monday (December 10), in New York for ovarian cancer," Subroto Ghosh, Manisha's manager, told IANS.
Speculation swirled about the health last week after she was hospitalised in Mumbai Nov 28. The rumours about her cancer are now confirmed.
In a post on her Facebook page Thursday, Manisha, 42, admits she was shocked to know about her illness, but she is confident all will be well soon.
"Dear friends, thank you for all your wishes. I am in good place and in good hands. With all your love and prayers I am sure I'll recover. It was shocking to know, but then life is full of surprises," Manisha wrote.
"One must deal with it and move on with faith and dignity. Whatever is the outcome, it is for best. I know that. So people, don't worry! I have had a beautiful life so far and I know, whatever will happen will all be good. Thank you from the bottom of my heart for your prayers... love, M Koirala," she added.
The actress, who belongs to an influential family in Nepal, has taken the news gracefully and says it is a part and parcel of life. She only wants her family, friends and fans to be happy.
"I am writing this as a request - please no sadness, I have told my closest friends and family too. This is part of life," she said.
"I am fine and will be fine no matter the outcome. I am in gratitude with all the gifts I have received from this life - like your love and prayers. Let us celebrate life in all forms. Thank you again for your prayers," she added.
Manisha was admitted to Mumbai's Jaslok Hospital Nov 28 after she reportedly fell unconscious. However, the reason behind her illness was not made clear. Later it was reported that she is flying to the US for treatment.
The actress, who has worked in critically acclaimed films like "Dil Se" and "1942: A Love Story", made her debut with "Saudagar" in 1991. She recently made a comeback with Ram Gopal Varma's "Bhoot Returns".