Poor guy. He fell down a few days ago and was diagnosed with a bleeding ulcer, but upon further review it’s quite a bit worse than that: B-cell lymphoma, which is fast-growing but evidently responds well enough to chemo that half the people who are treated for it recover. Here’s hoping.

The Democrat still plans to finish out his current term – his fifth in the Senate – and seek re-election in 2014.

“This doesn’t change any of that,” Lautenberg’s chief aide, Dan Katz, said of the senator’s political plans. “After he receives his treatment, back to normal.”

Moments ago, Lautenberg’s office issued a statement from the senator’s oncologist, James F. Holland, saying:

“We expect a full and complete recovery for Senator Lautenberg. The senator will be treated with chemotherapy administered approximately every three weeks. We anticipate that he will receive between six and eight treatments, and in between treatments, the senator is expected to be back at work in the Senate.”

He’s 86, which means he’d be seeking reelection in 2014 as … a 90-year-old cancer survivor. He can take as much time away from Congress as he needs to recuperate — remember how long Tim Johnson’s absence was after he had that stroke? — but this is another thorn in Reid’s side in the short term. He’s been busy looking for the 60th vote for the Democrats’ jobs bill and now, suddenly, he has to look for a 59th vote too. When it rains, it pours.

Something worth flagging in case Lautenberg opts for early retirement: New Jersey Democrats introduced a bill in the state legislature back in November, almost certainly with him in mind, to replace special elections for vacant U.S. Senate seats with a rule that would let the governor appoint a successor. With one catch — the governor could only appoint someone from the same party as the outgoing senator. Obviously, that’s a response to Chris Christie’s gubernatorial win, with state Dems worried that in this political climate a special election would be no automatic win even in a state as blue as Jersey. Their fears proved well founded two months later in Massachusetts; I wonder what’ll happen to that bill in light of today’s news.