Cristina Fernandez, Argentina's president, has returned home from a Buenos Aires hospital after medical tests analysing her surgically removed thyroid gland revealed no trace of cancer, which she was "falsely" diagnosed with last month, her spokesman says.

The operation to remove the gland went well. However, when the gland was analysed it turned out to have never contained cancerous cells, Alfredo Scoccimaro, Frenandez's spokesman, said on Saturday.

"The original diagnosis has been modified," he told a news conference. "The presence of cancer cells was discarded."

The president is expected to return to work late this month.

Several hundred Fernandez supporters had been camped out near the hospital where she was treated, carrying banners that said, "Strength Cristina".

The president, who won re-election with 54 per cent of the vote in October, is popular among Argentines who agree with her generous welfare spending.

Business leaders and farmers in the country's key grains sector however say her state-centric interventions in the economy scare away investment.