VATICAN CITY -- Surgeons removed a large tumor from the colon of Pope John Paul II yesterday and predicted a complete recovery, although it will take four or five days to determine conclusively whether the growth was malignant.
The 72-year-old pontiff underwent four hours of surgery at the Gamelli Hospital in Rome. The operation included the removal of the tear-shaped, 2 1/2 -inch-long tumor and more than six inches of the colon. The pope's gallbladder, which was found to contain stones, was also taken out.
Later, the Vatican said that the pontiff was awake and resting comfortably and was expected to remain in the hospital for about 10 days. The pope is "in very good shape," said Dr. Attilio Maseri, a cardiologist who is caring for him.
The surgery was followed with rapt attention by the press and a crowd of well-wishers who kept a vigil under the pope's 10th-floor window at the sprawling modern hospital building as the early morning surgery proceeded.
The pope entered the hospital Sunday for tests after complaining of abdominal swelling and pain.
On the morning of the surgery, the pope rose before dawn to celebrate Mass alone at a makeshift chapel in his hospital quarters, said his spokesman, Joaquin Navarro.
After the operation, the official Vatican medical bulletin said "the operation was radical and curative because the lesion [tumor] was of a benign nature."
But the size of the tumor led American experts on gastrointestinal cancers to express strong concerns that it might turn out to be cancerous, despite the results of preliminary tests showing no evidence of malignancy.
"It is a very big tumor," said Dr. Jorge Valenzuela, a professor of medicine at the University of Southern California Medical School. "The chances are very high that it is a malignancy."
"There is a high likelihood that it is a malignancy," said Dr. Michael J. Zinner, chairman of the department of surgery at University of California, Los Angeles, Medical Center. Nevertheless, he said there was also "a high likelihood" that a malignancy would have been cured by the operation.
A more detailed examination of the entire tumor, as well as tissue from the surrounding intestine and nearby lymph nodes, is necessary before pathologists can offer a final verdict on whether malignancy is present. If a malignancy is found, these further microscopic exams will also allow doctors to determine if the tumor has spread and if the operation was curative.
The tumor was found by a colonoscopy, an exam of the colon with a lighted tube. It was located in the final part of the colon, which connects to the rectum. At 2 1/2 inches, the tumor was much larger than the normal diameter of the colon, explaining why it caused the pontiff significant discomfort.
The gallstones were discovered with a CAT scan of the abdomen, an X-ray test. While the stones probably had nothing to do with the pontiff's discomfort, it is fairly common for surgeons to remove the gallbladder when abdominal surgery is being performed for other reasons and when the gallbladder removal does not increase the overall risk of the operation, according to Dr. Zinner. The gallbladder aids digestion of food, but people can live without it.
After leaving the hospital, the pope is to continue his convalescence at Castel Gandolfo, his summer residence. His spokesman said he still plans to make a visit to the Dominican Republic and other countries in October to commemorate the 500th anniversary of Columbus' voyage to the New World.