Lymphadenektomie beim Schilddrüsen- und Nebenschilddrüsenkarzinom

Prognostic value of lymph node metastases of differentiated thyroid cancer (DTC) according to the local advancement and range of surgical excision

In differentiated thyroid carcinoma (DTC) with primary tumor smaller than 1 cm, the routine central lymph node (LN) dissection is questioned, due to increased risk of post-surgery complications and lack of confirmed benefit.

Aim

The analysis of prognostic significance of LN metastases, in DTC patients to verify the potential role of central neck lymphadenectomy on disease staging.

Materials and methods

The group of 195 DTC patients, primarily operated between 2004 and 2005, was retrospectively analyzed. 184 patients after radical operation, with no distant metastases diagnosed before surgery, were included into analysis. LN metastases were observed in 55 of cases (28%). In 124 cases only dissection of central LN compartment was performed, in 36 patients also uni- or bilateral modified cervical lymphadectomy was carried out. In 24 patients with tumor limited to the thyroid gland without suspicious lymph nodes, the routine central lymph node dissection was not done.

Results

Median follow-up was 4 years. The 5-year overall and disease free survival standardized ratio were 100% and 95% respectively. The risk of LN metastases increased with the more locally advanced cancer. In the group of 124 patients, in whom only central LN dissection was performed, LN metastases were diagnosed in 15 cases (12%). No significant relation between multifocality and frequency of central and/or lateral LN metastases was noticed. Significant correlation between N feature and extrathyroidal invasion was observed (p = 0,0003). The presence of LN metastases was related to worsening of disease free survival from 99 to 90%. During the follow-up recurrence occurred in 6 (3%) cases. In 24 patients in whom only total thyroidectomy was done, no local or distant recurrence was observed. The assessment of early postoperative complications (hypoparathyroidism, paresis of vocal cords) indicated that the frequency of early calcium balance disturbances was significantly lower in patients in whom central LN dissection was not performed (p = 0,04)

Conclusions

Our result indicate that in the early diagnosis of thyroid cancer, the occurrence of LN DTC metastases is rarer and was observed only in 12% of elective dissections of central LN node compartment, if no lateral dissection was indicated due to the lack of clinical suspicion. In DTC patients with tumor diameter <1 cm and no sonographical or inraoperative suspicion on LN involvement, routine central lymphadenectomy may be not obligatory.

[Globus sensation as a sign of medullary thyroid carcinoma]

Medullary carcinomas represent 4% of all thyroid carcinomas. Most important for diagnosis are ultrasound criteria and determination of serum calcitonin, using the pentagastrin test if necessary. We report on a 51-year-old woman who was suffering from persistent globus sensation. Ultrasound examination detected a small thyroid nodule with microcalcification in the right thyroid gland. Serum calcitonin representing the most important tumor marker was massively increased. We performed a total thyroidectomy with dissection of the paratracheal compartments and a conservative neck dissection on the side of the tumor. Postoperatively, serum calcitonin decreased but still remained increased overall. Because there is no other therapeutic option besides surgical treatment, the initial intervention is of tremendous importance. In addition, examination for a possible hereditary medullary thyroid carcinoma is required, which influences the patient's prognosis considerably and necessitates screening examinations of other relatives.