Surgeons removed a lesion from Venezuelan President Hugo Chavez's pelvis and the socialist leader is in "good physical condition" after the operation, his vice president said on Tuesday.
Chavez, 57, had new surgery in Cuba despite his previous insistence that he had been cured of cancer after two procedures by doctors in Havana last year.
The latest health setback has fueled fresh doubts about Chavez's health, his ability to campaign for re-election in October and his fitness to govern the South American nation for another six-year term if he wins.
"President Chavez is in good physical condition. ... The pelvic lesion was extracted completely along with the surrounding tissue," Vice President Elias Jaua told Venezuela's parliament in Caracas, smiling as jubilant supporters applauded and chanted "Chavez will not leave!"
"There were no complications relating to his local organs. ... He is recovering correctly," Jaua added, saying tests would be carried out on the extracted tissue in the coming hours to determine whether the lesion had been malignant.
The vice president did not say what type of cancer Chavez has been fighting. Jaua did not mention any possible follow-up treatment, and did not say when Chavez would return home.
One medical source close to the team that had been treating the Chavez in Venezuela said the surgery on Monday night at Havana's closely guarded Cimeq Hospital had lasted 90 minutes.
Before departing Venezuela on Friday, Chavez said he would need surgery on a probably malignant lesion found in his pelvis, where a large cancerous tumor was removed in June. He has also said he might need radiation treatment after the new operation, raising the prospect of another lengthy convalescence.
"President Chavez appreciates, from his heart, the warm support he has received from the Venezuelan people, as well as the countless expressions of solidarity from men and women all over the world," Jaua said.
Sunil Daryanani, an oncologist at the Hospital de Clínicas Caracas, said the vice president presented a positive scenario, but that many details remained unknown.
"We have to wait for the pathology results to see what they found, which should take three to five days," he said, adding that a patient's recuperation time for the procedure that Jaua described would normally be a week to 10 days.
Chavez traveled to Cuba for treatment because the communist-led Caribbean island's former president, Fidel Castro, is a close friend and his main political mentor.
According to Chavez, it was Castro who broke the news to him by his hospital bed that he had cancer last June. Chavez has since returned for chemotherapy sessions and medical tests in Cuba, where he is guaranteed privacy and tight security.
Chavez's health could hobble his re-election campaign, when he would normally want to crisscross the country during the run-up to the Oct. 7 vote.
He faces opposition candidate Henrique Capriles, a 39-year-old state governor who hopes to woo former Chavez voters with a promise of a Brazilian-style "modern left" government.
Before the announcement that he would need more surgery, opinion polls showed Venezuelans broadly split - a third pro-Chavez, a third pro-opposition and a third undecided.
But the polls indicate Chavez might have a slight edge in voter enthusiasm - attributed to his popularity among the poor and an increase in welfare spending for the most needy.
While Chavez may get a "sympathy bump" in the polls in the weeks ahead, voter perceptions of weakness - particularly in contrast with Capriles' youthful image - could offset that.
Chavez has avoided grooming a successor and has dominated the political stage himself since his first election win in 1998, so rumors abound as to who from his inner circle could take over if he were to be incapacitated.
None of his closest supporters share his man-of-the-people charisma, or the political and rhetorical talents that have forged his close connection with Venezuela's poor majority.
The opposition has called on Chavez to name a temporary replacement during his recovery, but that is unlikely given that he chose to govern from his hospital bed in Havana during his extended absences last year.
Venezuelans are talking about little else than Chavez's health. Some still suspect he may have even invented the cancer to draw sympathy and create the image of a conquering return to fitness, while others speculate he could die within months.
Supporters have been holding vigils for him around the nation. State media has been awash with goodwill messages and old footage of a young and vigorous Chavez.
The Gaza Strip at night as seen from the International Space Station.
76-year-old Fuad Masum, who also served as the first prime minister of autonomous Iraqi Kurdistan in 1992-1993, reportedly emerged as the only candidate of the Kurdish blocs.
A missing Air Algerie plane that lost contact en route from Burkina Faso is an Airbus A320 carrying 110 passengers to Algiers
1,300 tonnes of chemicals removed from Syria were now being destroyed at various locations
Nearly 300 people, 193 of them Dutch citizens, were killed when the Malaysia Airlines plane en route from Amsterdam to Kuala Lumpur was brought down in eastern Ukraine
Ukraine's army has forced the rebels back to their two main strongholds of Donetsk and Luhansk, taking villages and suburbs around them
Politicians and activists have complained that while Ukraine has a new president, it has yet to elect a new parliament since the toppling of pro-Russian leader Viktor Yanukovich
Udaltsov, who has been under house arrest since February 2013, and Razvozhayev were accused of coordinating the protests which turned violent on May 6, 2012
PM's resignation paves the way for an interim government to take over in August and a general election in October
Human rights group B'Tselem will petition Israel's supreme court after advert was deemed to be 'politically controversial'
The bus crossed the track at an unmanned crossing in Telangana state without stopping to check if the way was clear, said Indian Railways spokesman
A huge attack on a prisoner convoy in Iraq has reportedly killed at least 60 people.
Salzburg police said on Thursday around 20 people with flags and placards, mostly Austrians of Turkish origin, stormed the pitch shouting slogans about the Gaza conflict
The leaders of rivals China and Taiwan both expressed condolences over the deaths. Ten people were injured and taken to hospital.
The Strasbourg-based court ruled that Poland had violated articles of the convention on, among others, the prohibition of torture, the right to liberty, and to an effective investigation of their allegations.
More than 50 people have died so far in the violence that has deepened fears post-war Libya is slipping into lawlessness