Endocrine Abstracts

Background and patients: The clinical significance and management of papillary thyroid microcarcinoma (PTMC) is widely debated. The objective of this study was to assess the clinical presentation, tumor characteristics and the outcome of the disease in patients with PTMC. In this retrospective study we evaluated 286 patients who were followed for a minimum of three years.

Results: Of the 286 patients with a mean age 48.9 years, 226 (79%) were females. Two hundred and sixty one patients (91.2%) underwent a near total and 25 patients an incomplete thyroidectomy. PTMC was discovered incidentally in 248 (86.7%) patients undergoing surgery for other pathology not related to thyroid malignancy, while 38 patients were operated for suspicious FNAB or positive lymph nodes. Unifocal disease was detected in 182 (63.6%) patients; with 92 having a focus of 1–5 mm and the remaining a focus of 6–10 mm. Multifocal disease was detected in 104 (36.3%) patients. From these patients, none had distant metastases; however, loco-regional extension and lymph-node involvement were detected in 13 and 29 patients respectively. Two hundred twenty six (79%) patients underwent adjuvant radioiodine ablation for worrisome histologic subtypes, thyroid capsule invasion, multifocality or thyroid remnants. The mean follow-up was 8.19 years. Disease recurrence was observed in only one patient (with lobectomy and radioiodine ablation), 20 years after the initial diagnosis. Six patients had persistent disease during the follow-up period, all of whom had undergone near-total thyroidectomy and remnant ablation. The remaining 279 (97.5%) patients were disease free.

Conclusions: PTMC appears to have a benign course in the majority of patients initially treated with near-total thyroidectomy and therefore, according to the revised ATA thyroid cancer guidelines, additional radioiodine ablation is not justified. However, an aggressive subtype of PTMC seems to exist. More prospective studies or probably molecular markers are needed, in order to identify this subtype.