RESUMO
Objective To explore the constituent ratio and clinical characteristics of multifocal thyroid papillary carcinoma (MPTC).Methods The clinical data of 1616 cases of papillary thyroid carcinoma(PTC) were retrospectively analyzed from January 2002 to December 2011 of the First Affiliate Hospital of Dalian Medical University,which operated at the first time and confirmed by pathology.The change of constituent ratio of MPTC in PTC was analyzed and the differences of the clinical characteristics of the multifocal group and single focal group were analyzed.Results The constituent ratio of MPTC in PTC was increasing from 8.33％ (4/48) in 2002 to 30.38％ (96/316) in 2011 gradually.Compared to the single focal group,MPTC group had higher rate of neck lymph node metastasis(45.09％ vs 25.02％ ; P =0.000) and extrathyroidal invasion (20.95％ vs 9.04％ ;P =0.000).Compared with pure microcarcinoma,none pure microcarcinoma had higher rate of neck lymph node metastasis (P =0.000).More than two focuses has higher rate of neck lymph node metastasis than two focuses (P =0.000).The rate of recurrence with lymph node metastasis was higher than that without lymph node metastasis (24.05％ vs 8.98％ ;P =0.000) conformed by postoperative pathology.Conclusions The number and constituent ratio of MPTC in PTC is increasing gradually.MPTC group has high proportion of lymph node metastasis and extrathyroidal invasion than single focal group.None pure microcarcinoma has higher rate of neck lymph node metastasis than pure microcarcinoma;more than two focuses has higher rate of neck lymph node metastasis than two focuses.The recurrence rate is correlated with the rate of lymph node metastasis.