One Mstislav Rostropovich, 26-year-old cellist from Russia, arrived in Washington 25 years ago to play Lisner Auditorium. They couldn't even fill the house.

Or as Rostropovich -- the now older, wiser, much more famous and a little more English-speaking conductor of the National Symphony Orchestra -- put it last night to Patrick Hayes, the man who took a chance on him: "I make to you near bankruptcy."

Probably not. But they won't have any problem filling the 25th anniversary concert that Rostropovich will give April 14, playing the same pieces that he played April 14, 1956.

"He's still the world's finest cellist, Casals being dead," said Hayes, head of the Washington Performing Arts Society.

Rostropovich is also a Washington personality, the reasons for which showed last night at a party given by Buffy and William Cafritz and the 25th anniversary committee (a group of officials from the National Symphony Orchestra, the Washington Performing Arts Society, and the American University) at the Cafritz home in Bethesda.

For starters, Slava -- as his intimates and the rest of Washington call him -- arrived buoyant. From the dentist.

"My English now is worse than ever," he said. "Part of my English stays in my teeth."

And then there were his famous bear hugs and kisses for Hayes and everyone else in the room.

"You know when my wife was saying Rostropovich was the greatest kisser around, I was kind of hurt," Dale Miller good-naturedly told friends. k

"At the board meeting this afternoon," said his wife, National Symphony board member Scooter Miller, "he was kissing everyone and he said, 'You know, I have to kiss all the ladies.' I said, 'What do you mean, the ladies? 'You kiss all the men, too'".

After the maestro dashed out for a rehearsal, the Rostropovich stories kept going.

"I had the pleasure of putting a hood on Rostropovich's shoulders," said American University Provost Milton Greenberg of the honorary degree bestowed upon Rostropovich last Sunday. "He hugged me so hard I had to have my glasses fixed the next day."

The concert is part of the celebration being planned. It is invitation only -- surprise -- free. "This is not a benefit in disguise," Mary Munroe, chairman of the anniversary committee, told the group. "It's a celebration."

The committee is also trying to get April 14 proclaimed Rostropovich Day or some variation of that.

And what with all the honor being bestowed upon Patrick Hayes, Leonard Silverstein, chairman of the National Symphony Orchestra board -- who walked all the way from next door to the Cafritz party -- mentioned that the symphony was still looking for someone to be executive director.

"Pat, I know you were once an NSO manager," said Silverstein. "We are engaged in a very vigorous search now and if you want . . ."

The room dissolved into guffaws.