Gov. Phil Murphy of New Jersey said on Saturday that he would undergo surgery next month to remove a tumor on his kidney.

“I’ve got a tumor on my left kidney and will undergo a partial nephrectomy in early March to remove it,” Mr. Murphy, a Democrat, wrote on Twitter. “The prognosis is very good and I’m profoundly grateful to my doctors for detecting the tumor early.”

He added that “over 50,000 New Jerseyans will hear the words ‘you have cancer’ this year, so I’m far from alone here.”

Mahen Gunaratna, the governor’s communications director, said the three-centimeter tumor was discovered during a recent checkup. He says that it is impossible to know whether the tumor is cancerous until it is removed, but that in 90 percent of similar cases, it is.