Buenos Aires (CNN) -- Argentina's president will undergo surgery next week after doctors diagnosed her with thyroid cancer, a spokesman said Tuesday.
Routine medical tests last week uncovered papillary carcinoma in President Cristina Fernandez de Kirchner's thyroid gland, presidential spokesman Alfredo Scoccimarro said.
Medical exams indicate that the cancer has not spread to her lymph nodes or grown beyond the thyroid gland, he said.
Doctors are scheduled to operate on Fernandez on January 4. She will take a medical leave and relinquish power to the South American nation's vice president from January 4-24, Scoccimarro said.
Fernandez, 58, was sworn in for a second four-year term earlier this month after she won re-election with more than 54% of the vote.
She became Argentina's president in 2007. Her husband, Nestor Kirchner, was president from 2003-2007. He died in October 2010.
During Fernandez's presidency, Argentina's economy has enjoyed sustained growth of about 8% annually.
Papillary carcinoma is the most common type of thyroid cancer and has an excellent survival rate, according to the U.S. National Library of Medicine.
More than 95% of adults with papillary thyroid carcinoma survive at least 10 years, according to a description on the library's website. Treatment includes surgery, radioactive iodine and medication, the library says.
Possible complications in surgery can include damage to a nerve that controls the vocal cords or accidental removal of a gland that helps regulate blood calcium levels, according to the medicine library.
Recently doctors have diagnosed several South American leaders with cancer.
Paraguayan President Fernando Lugo was diagnosed with non-Hodgkin's lymphoma in 2010.
Venezuelan President Hugo Chavez announced that doctors had diagnosed him with cancer in June. He did not specify what kind of cancer he had, but after undergoing several rounds of chemotherapy, he said in October that he had been cured.
Former Brazilian President Luiz Inacio Lula da Silva is undergoing treatment for throat cancer.