Clinicopathological characteristics of incidental papillary thyroid microcarcinoma in an endemic goiter area

Abstract

Papillary thyroid microcarcinoma (PTMC) is a common malignant disease of the endocrine system, which has rapidly increased in incidence and prevalence in recent decades. The aim of our paper was to identify correlations between pathological and clinical features of cases of PTMC. A total of 612 patients of both genders, who were operated on for benign thyroid diseases in the 3rd Surgical Unit of St. Spiridon University Hospital of Iasi, were monitored for a period of 2 years. According to pathological reports, PTMC was diagnosed in 144 cases. Of those cases, 81.2% were female and 18.8% were male, with an overall mean age of 54.77 ± 11.9 years. The mean diameter of tumors was 3.04 ± 2.2 mm (75.7% were under 5 mm), and 35.4% were multifocal tumors. Of all tumors studied, 76.4% were the follicular variant, 13.2% were conventional, and 10.4% of cases included tall cell, hobnail, or columnar variants. The underlying diseases were multinodular goiters (73.6%), adenomas (25%), Hashimoto thyroiditis (17.4%), Basedow's disease, and other types of hyperthyroidism (4.9%), primarily hyperparathyroidism (7.6%), with a small percentage presenting a combination thereof. Extracapsular invasion was present in 14.6% while 5.6% presented perineural invasion and 0.7% of cases had vascular invasion. Lymphatic emboli were found in 9% of cases and lymph node metastasis in 5.6% of cases. PTMC is not as innocent as believed, and further studies, performed on larger batches, would be necessary in order to identify high oncological risk cases and to determine when a more aggressive surgical approach is indicated.