Immediate Surgery Might Be a Better Option for Subcapsular Thyroid Microcarcinomas

Abstract

For high-risk papillary thyroid microcarcinomas (PTMCs), immediate surgery is recommended. This study aimed to evaluate the location of PTMCs in the thyroid lobe and determine whether location is associated with an aggressive biology and the necessity of immediate surgery. This retrospective study included 288 patients who underwent initial surgery for PTMC. Clinical data were extracted. Subcapsular thyroid microcarcinomas (STMs) and nonsubcapsular thyroid microcarcinomas (NSTMs), distinguished by ultrasound, were compared in terms of tumour size, extrathyroidal extension, cervical lymph node metastasis, and multifocality. The preoperative ultrasound features predictive of recurrent laryngeal nerve (RLN) involvement were assessed. There were no statistical differences in tumour size (P = 0.985), multifocality (P = 0.866), lymph node metastases to the central compartment (P = 0.154), or lateral lymph node metastases (P = 0.929) between STM and NSTM groups. Macroscopic extrathyroidal extension was exclusively found in the STM group. For assessing RLN involvement, the sensitivity, specificity, and positive predictive value of the presence of an abnormal thyroid capsule margin between the STM and the presumed RLN course, assessed on preoperative ultrasonography images, were 100%, 43.3%, and 43.3%, respectively. Immediate surgery appears to be a better option than conservative treatment for these high-risk STM patients.

2020 Chinese guidelines for ultrasound malignancy risk stratification of thyroid nodules: the C-TIRADS

“…(2) Multifocality, subcapsular nodule, trachea, and recurrent laryngeal nerve invasion are considered as predictors of poor prognosis of PTC [145][146][147][148][149]. Thus, when category 4A nodules are multiple, or immediately adjacent to the trachea or recurrent laryngeal nerve, ultrasound-guided FNA can be considered if the nodule is >10 mm; (3) For solitary nodule of ≤10 mm that is not immediately adjacent to the capsule, trachea or recurrent laryngeal nerve, regular follow-up is optional; (4) If the nodules are too large to cause compression symptoms or cosmetic problems, the management principle of TIRADS 2-3 nodules can be referred to, provided the biopsy results are benign.…”

Meta Analysis of the Outcomes in Doing Active Surveillance and Surgical Approach for Micropapillary Thyroid Carcinoma

“…Micropapillary thyroid carcinoma has a less aggressive behavior and mostly presence without any symptoms [3]. Recent studies have shown more than 400% increase in micropapillary thyroid carcinoma prevalence along with the improvement of imaging technologies [33].…”

“…Recently, some authors classified there were low-risk and high risk disease. Thus, immediate surgical management was being reconsidered and debated [3]. Active surveillance has emerged to address the concern for over-treatment of low-risk papillary microcarcinoma [4].…”

What is the difference between the tall cell variant and the classic type of papillary thyroid carcinoma on ultrasonography?

“…According to K-TIRADS, decision-making concerning the FNA of subcentimeter high-suspicion nodules depends upon the management strategy of the thyroid microcarcinomas and FNA is recommended in patients with poor prognostic factors, including suspected cervical LN metastases, obvious ETE to adjacent structures, confirmed distant metastases, or suspected medullary thyroid cancer [23]. However, subcapsular location of tumor also known to have been associated with aggressive behavior of papillary thyroid microcarcinoma, and it may be on the same spectrum of disease progression with ETE as a more frequent subcapsular location may more often progress to ETE [27][28][29][30]. Our results are compatible with those studies in terms of different therapeutic strategies being required when dealing with aggressive variants of PTC that tend to show more ETE-favoring preoperative US findings.…”