THE PLOT THICKENS: JOBS HAD LIVER TRANSPLANT

Nonetheless, "Steve continues to look forward to returning at the end of June, and there's nothing further to say," said Apple spokeswoman Katie Cotton.

Jobs, who has been on medical leave from Apple since January to treat an undisclosed medical condition, may be encouraged by his physicians to initially "work part-time for a month or two" on his return, a person familiar with the thinking at Apple told reporters Yukari Kane and Joann Lublin. That could mean "a more encompassing role" for COO Tim Cook, who’s been running the show since Jobs left the day-to-day. Further, Cook may be appointed to Apple's board in the not-too-distant future, according to the same person.

At least some Apple directors were aware of Jobs’ surgery, the story continued. As part of an agreement with Jobs in place before he went on leave, some board members have been briefed weekly on the CEO's condition by his physician.

The 54-year-old Jobs revealed on Aug. 1, 2004, that he’d just been treated for a rare form of pancreatic cancer, called islet cell neuroendocrine tumor, which can be cured by surgery if removed promptly. In a memo to Apple employees, he said that the tumor was diagnosed in time, that he had undergone surgery to remove it and that he wouldn't require any chemotherapy or radiation.

But concerns returned last year during several Apple dog-and-pony shows when it became obvious that Jobs had lost a lot of weight, and was looking gaunt and sickly. In early January, he said he had a hormone imbalance that was "relatively simple and straightforward" to treat. But about a week later, he announced that the issue was more complex than he had thought, and in a letter to staff he said he’d be taking a leave and that Cook would take over while he was away.

Surgeon William Hawkins explained to the WSJ that the type of slow-growing pancreatic tumor Jobs had five years ago will commonly metastasize in another organ during a patient's lifetime, and that the organ is usually the liver. "All total, 75% of patients are going to have the disease spread over the course of their life," said Dr. Hawkins.

Getting a liver transplant to treat a metastasized neuroendocrine tumor is controversial because livers are scarce and the surgery's efficacy as a cure hasn't been proved, Dr. Hawkins added. He said that patients whose tumors have metastasized can live for as many as 10 years without any treatment, so it’s hard to determine how successful a transplant has been in curing the disease.

The specifics of Jobs's surgery couldn't be established, but having the procedure done in Tennessee makes sense because its list of patients waiting for transplants is shorter than in many other states, as is the typical waiting period. The five-year survival rate for liver-transplants patients is around 75%.