Central neck dissection in papillary thyroid carcinoma: Results of a retrospective study

Nomogram to assess risk of central cervical lymph node metastasis in patients with cN0 papillary thyroid carcinoma

OBJECTIVE

This study developed and validated an individualized prediction risk model for the need for central cervical lymph node dissection in patients with cN0 papillary thyroid carcinoma (PTC) diagnosed by ultrasound.

METHODS

Upon retrospective review, derivation and internal validation cohorts comprised 1585 consecutive patients with PTC treated from January 2017 to December 2019 at Hospital A. The external validation cohort consisted of 406 consecutive patients treated at Hospital B from January 2016 to June 2020. Independent risk factors for central cervical lymph node metastasis (CLNM) were determined through univariable and multivariable logistic regression analysis. An individualized risk prediction model was constructed and illustrated as a nomogram, which was internally and externally validated.

RESULTS

The following risk factors of CLNM were established: the solitary primary thyroid nodule's diameter, shape, calcification, and capsular abutment-to-lesion perimeter ratio. The areas under the receiver operating characteristic curves of the risk prediction model for the internal and external validation cohorts were 0.921 and 0.923, respectively. The calibration curve showed good agreement between the nomogram-estimated probability of CLNM and the actual CLNM rate in the three cohorts. The decision curve analysis confirmed the clinical usefulness of the nomogram.

CONCLUSION

This study developed and validated a model for predicting risk of CLNM in the individual patient with cN0 PTC, which should be an efficient tool for guiding clinical treatment.

Incidental thyroid carcinomas. A retrospective study

AIM

The aim of the present study is to report our series of incidental thyroid carcinomas in the last 15 years and their follow-up, discussing therapeutics indications and surgical choices.

PATIENTS AND METHODS

We have considered 1793 patients operated on Surgical Sciences Department of "Sapienza" University of Rome from January 1, 2001 to December 31, 2015. The study was conducted on 83 totally thyroidectomized patients with a real incidental thyroid carcinoma, by clinical, laboratory and instrumental controls. Whole-body scan was the most important test in postoperative evaluation.

RESULTS

In our series, the incidence of incidental carcinomas was 4.62%. Compared to the total number of cancer patients, the percentage is 21,9%. In 15.66% of cases there was multifocality and in 7.23% also bilaterality. Regarding the histological type, in all cases they were papillary carcinoma. The size of the neoplastic lesions ranged from a minimum of 3 to a maximum of 10 mm. Whole-body scan revealed lymph node metastasis in 57.69% of patients.

DISCUSSION

Comparing these data with our previous studies we have seen a significant increase in incidence of incidental thyroid carcinomas over the years. Our therapeutical choice is total thyroidectomy and complection thyroidectomy after lobectomy, because of a relevant percentage of multifocality and/or bilaterality of these tumors. Many Authors on the contrary prefer a more conservative approach invoking the good prognosis of these tumors. The 57.69% of lymph node metastasis at postoperative whole-body scan comfort us in our setting.

CONCLUSION

Incidental thyroid carcinomas are not uncommon. We consider only tumors until 1 cm in diameter. Multifocality and bilaterality are often present such as occult lymph node metastasis. Our therapeutical choice is total thyroidectomy in order to conduct a proper follow-up.

Decision making for the central compartment in differentiated thyroid cancer

The central compartment is a common site for nodal spread from differentiated thyroid carcinoma, often occurring in patients without clinical or ultrasonographic (US) evidence of neck lymph node metastasis (cN0). However, the role of elective central compartment neck dissection (CND) among patients with DTC remains controversial. We performed a systematic literature review, also including review of international guidelines, with discussion of anatomic and technical aspects, as well as risks and benefits of performing elective CND. The recent literature does not uniformly support or refute elective CND in patients with DTC, and therefore an individualized approach is warranted which considers individual surgeon experience, including individual recurrence and complication rates. Patients (especially older males) with large tumors (>4 cm) and extrathyroidal extension are more likely to benefit from elective CND, but elective CND also increases risk for hypoparathyroidism and recurrent nerve injury, especially when operated by low-volume surgeons. Individual surgeons who perform elective CND must ensure the number of central compartment dissections needed to prevent one recurrence (number needed to treat) is not disproportionate to their individual number of central compartment dissections per related complication (number needed to harm).