Abstract
Introduction: Encapsulated follicular variant of papillary thyroid carcinoma [EFV-PTC] is an indolent variant of papillary thyroid carcinoma [PTC]. Based on capsular and vascular invasion, EFV-PTCs are divided into non-invasive [NIEFV-PTC] and invasive [IEFV-PTC] subtypes. Recently, NIEFV-PTC was re-classified as a non-malignant thyroid neoplasm. This study evaluates the clinicopathological characteristics and management of NIEFV-PTC among patients treated at King Abdulaziz Medical City, Jeddah, Saudi Arabia
Methods: A Retrospective cross-sectional study involving 44 cases of NIEFV-PTCs. They were identified after reviewing the pathology reports of all thyroid gland surgeries performed from January 2011 to December 2015 at King Abdulaziz Medical City. Clinical data and follow up were obtained from patient's records.
Statistical analysis used: IBM SPSS 22 [SPSS Inc., Chicago, Il, USA] was used. Chi-square and one-way ANOVA tests were used to delineate statistical significance.
Results: Cases included 40 women and 4 men, with a mean age of 35-years-old. All had a unilateral tumor[s] [37 unifocal and 7 multifocal], with an average tumor size of 3.4 cm. Histologically, these tumors were surrounded by a well-defined capsule, with no capsular or vascular invasion and all lacked extrathyroidal extension, perinural invasion, positive resection margins, and/or high mitotic activity. No lymph node or distant metastases were identified. Patients were treated by total thyroidectomy [n=24], completion thyroidectomy [n=19], or lobectomy [n=1] combined with radioactive iodine ablation in 25 patients with a mean dose of 92.8 +/- 25.4 mCi. A median follow-up of 19 months was available for 95.5% patient, none of them demonstrated any evidence of disease recurrence/metastasis.
Conclusions:
NIEFV-PTC is an indolent thyroid tumor with very low-likelihood of metastases. To avoid over-treatment, we recommend the incorporation of the recently coined term [NIFTP] into the management algorithms for patients with thyroid tumors.