Silvio Berlusconi, the former Italian prime minister, is being treated in the intensive care unit of a Milan hospital for a lung infection related to a kind of leukemia that he has “had for some time,” his personal physician said on Thursday.
A medical bulletin issued by the physician, Dr. Alberto Zangrillo, said Mr. Berlusconi, 86, had chronic myelomonocytic leukemia, which was not acute, and that he was being treated both for the lung infection and for the blood cancer. Dr. Fabio Ciceri, the hospital’s head of hematology and bone marrow transplantation unit, co-signed the bulletin.
Mr. Berlusconi had been admitted to the San Raffaele hospital on Wednesday, for what Foreign Minister Antonio Tajani, a close ally of Mr. Berlusconi and a member of his political party, had described as “a problem related to a previous infection.”
While Mr. Berlusconi has a history of medical problems, the announcement on Thursday was received throughout Italy with the sense of an era coming to a close. Politicians across the political spectrum spoke about how dominating a figure he had been on the national scene for nearly three decades.
Throughout the day, family members and close friends paid visits to the hospital, though few spoke to the reporters who converged there when Mr. Berlusconi was first admitted.
Mr. Berlusconi has dealt with a variety of health issues. He was treated for prostate cancer in 1997, though he did not publicly acknowledge it until three years later in a newspaper interview, saying at the time: “I went through a nightmare lasting months. I am cured. I managed to come out of the tunnel.”
He also had a pacemaker installed in 2006 and had open-heart surgery to replace a faulty heart valve a decade later. In September 2020, he was knocked out by a case of Covid, which he described as an “infernal disease” and “very ugly.”
He spent 10 days at San Raffaele then, returning to the hospital for a considerably longer stay 10 months later because of long-term effects from the coronavirus, according to Italian news reports.
Mr. Berlusconi spent four days at the hospital again last week, for what Italian news outlets reported were routine medical checks. After being discharged, he posted upbeat messages on his Facebook page, including a photo last Sunday showing him smiling outside his home, surrounded by tulips.
Several lawmakers with Forza Italia, the political party that Mr. Berlusconi founded in 1994, said he had called them earlier on Thursday, something they took as an encouraging sign.
“I was relieved after the call,” said Paolo Barelli, the Forza Italia leader in the lower house of Parliament.
“His call is a sign of hope,” said the Senate vice president, Maurizio Gasparri. “He was positive, he called others, telling us to be alert, on the game,” the ANSA news agency reported.
Mr. Berlusconi, elected three times as prime minister, won a seat again in Parliament in September after spending nearly a decade on the political sidelines after being banned from office following a tax fraud conviction in 2012. But he continued to act as a kingmaker on the national scene.
Leaving the hospital on Thursday afternoon, Fedele Confalonieri, a close friend and the president of Mediaset, a broadcast company founded by Mr. Berlusconi, told reporters that there “is concern, but we’re optimistic.”