The histological features of papillary thyroid carcinomas 1.5 cm and less in size

Shin, Sun Hye; Na, Min Ah; Kang, Yang Ho; Son, Seok Man; Kim, In Ju; Kim, Yong Ki

Abstract

BACKGROUND: A number of studies have shown that papillary microcarcinomas have a more favorable prognosis than do the larger tumors. However, some microcarcinomas may have a negative outcome. So, we investigated the histological features of small (< or =1.5 cm) papillary thyroid carcinomas, and we compared them with the larger (>1.5 cm) tumors.
METHODS
Between January, 1996 and December, 2000, 178 patients were diagnosed and operated on for their differentiated papillary thyroid carcinoma at Pusan National University Hospital. We reviewed the charts and pathologic records of these patients and we analyzed them retrospectively. According to the tumor size 1.5cm, we divided the tumors into two groups and then compared the histological features.
RESULTS
Small papillary thyroid carcinomas have a favorable outcome in most cases. However, small papillary thyroid carcinomas present with signs of aggressiveness at presentation, including lymph node metastases (33.3%), multifocality (12.5%), bilateral involvement (12.5%) and extrathyroidal extension (16.7%). Compared with larger tumors, the frequency of theses signs was similar, except for lymph node metastases, in the small papillary thyroid carcinomas.
CONCLUSIONS
Approximately one third of the small papillary thyroid cancer 1.5 cm and less in size had neck lymph node metastases at presentation and the signs of aggressiveness were similarly present as compared with the larger tumors. We suggested that the standard treatment is desirable as a therapeutic strategy of small papillary thyroid carcinoma.