Background:

The incidence of papillary thyroid microcarcinoma (PTMC) is increasing.

Objective:

To analyze the long-term prognosis of PTMC.

Method:

Study population: patients with a histopathological diagnosis of PTMC (size ≤ 1 cm) treated according to the risk of recurrence of the Latin American Thyroid Society. Inclusion criteria: minimum follow-up of 2 years, availability of histopathological samples, and treatment compliance. Exclusion criteria: previous thyroid surgery, other synchronous malignancies or ectopic location of the PTMC. Study variables: persistences, recurrences and mortality.

Results:

Based on the risk of recurrence, PTMC has very low risk in 65.2% (n = 105), low risk in 17.4% (n = 28) and high risk in 17.4% (n = 28). In high risk patients, total thyroidectomy was performed in all cases, cervical lymphadenectomy in 57,1% (n = 16) and metabolic therapy with I131 in all cases. During a mean follow-up of 119,8 ± 65 months, 0.6% (n = 1) of recurrences took place. Risk factors associated to recurrence were not identified. No patient died due to MCPT.

Conclusions:

PTMC treated based on its risk of recurrence has a good long-term prognosis, without persistences, with a low number of recurrences and absence of disease-associated mortality.