Aims: To review differences in biological aggressiveness, clinical behaviors or selected surgical treatments between the PMC and the slightly larger PTC of 1.0<T<or=2.0 cm.
Methods: Two hundred and twenty-seven cases of papillary thyroid carcinoma not larger than 2.0 cm, diagnosed and treated at the Kuma Hospital, Kobe, Japan, with a 10-year follow-up from 1992 to 2003, were reviewed.
Results: The small PTCs demonstrated excellent outcomes, and persistent/recurrent disease was identified in only nine patients (4%). None of the patients died of the disease. A multivariate analysis revealed that massive extrathyroidal extension at presentation was the only independent prognostic factor for locoregional recurrence. Subdivision into PMCs and slightly larger tumors (1<T<or=2 cm) did not affect the excellent outcomes, but the patients in the latter subgroup received more lymph node surgery and displayed more aggressive clinico-histological features such as higher rates of extrathyroidal extension, lymph node metastasis, loss of polarity, invasive growth pattern and loss of cohesiveness.
Conclusions: Small PTC not larger than 2.0 cm could be considered as favorable a prognosis as PMC.