Authors: Yasuhiro Ito Akira Miyauchi Hiroyuki Inoue Mitsuhiro Fukushima Minoru Kihara Takuya Higashiyama Chisato Tomoda Yuuki Takamura Kaoru Kobayashi Akihiro Miya
Publish Date: 2009/11/30
Volume: 34, Issue: 1, Pages: 28-
Abstract
The recent development and spread of ultrasonography and ultrasonographyguided fine needle aspiration biopsy FNAB has facilitated the detection of small papillary microcarcinomas of the thyroid measuring 1 cm or less PMC The marked difference in prevalence between clinical thyroid carcinoma and PMC detected on mass screening prompted us to observe PMC unless the lesion shows unfavorable features such as location adjacent to the trachea or on the dorsal surface of the thyroid possibly invading the recurrent laryngeal nerve clinically apparent nodal metastasis or highgrade malignancy on FNAB findings In the present study we report comparison of the outcomes of 340 patients with PMC who underwent observation and the prognosis of 1055 patients who underwent immediate surgery without observationThe proportions of patients whose PMC showed enlargement by 3 mm or more were 64 and 159 on 5year and 10year followup respectively Novel nodal metastasis was detected in 14 at 5 years and 34 at 10 years There were no factors related to patient background or clinical features linked to either tumor enlargement or the novel appearance of nodal metastasis After observation 109 of the 340 patients underwent surgical treatment for various reasons and none of those patients showed carcinoma recurrence In patients who underwent immediate surgical treatment clinically apparent lateral node metastasis N1b and male gender were recognized as independent prognostic factors of diseasefree survivalPapillary microcarcinomas that are not associated with unfavorable features can be candidates for observation regardless of patient background and clinical features If there are subsequent signs of progression such as tumor enlargement and novel nodal metastasis it would not be too late to perform surgical treatment Even though the primary tumor is small careful surgical treatment including therapeutic modified neck dissection is necessary for N1b PMC patients
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