Management of Retropharyngeal Node Metastases from Thyroid Carcinoma

Parapharyngeal Nodal Metastasis in Papillary Thyroid Carcinoma: Catching Early

Background

Metastasis to parapharyngeal space in papillary carcinoma of the thyroid is rare and often missed in routine clinical and radiological investigations. Although contrast CT /MRI can be done to locate the parapharyngeal lesion, the diagnosis of metastasis mostly deepened upon aspiration cytology, which is a challenge in difficult anatomical locations. Here, we have emphasized the management dilemma of parapharyngeal metastasis in papillary carcinoma of the thyroid.

Case Report

A 30-year-old female presented with multiple right-side neck swelling for two months. Ultrasonography of right thyroid showed TIRAD V and left thyroid showed TIRAD II. Aspiration cytology of the right thyroid showed Bethesda III and aspiration cytology revealed thyroid follicles. Due to the diagnostic ambiguity, contrast-enhanced CT scan was advised. It revealed a hypervascular lymph node in the parapharyngeal space besides multiple right cervical lymph nodes and later changed the treatment plan.

Conclusion

- Metastasis to parapharyngeal space in Papillary carcinoma of the thyroid is rare and often missed on routine evaluation. Contrast-enhanced CT/MRI can be added as a primary investigation in challenging cases of suspicious malignancy of the thyroid.

Parapharyngeal Metastasis of Papillary Carcinoma of Thyroid Gland: A Case Report and a Review of the Literature

Papillary carcinoma is the most frequently encountered differentiated thyroid carcinoma. Usually, metastasis occurs along lymphatic pathways in the central compartment and along the jugular chain. Nevertheless, lymph node metastasis in the parapharyngeal space (PS) is a rare but possible event. In fact, a lymphatic pathway has been identified that connects the upper pole of the thyroid and the PS. We describe the case of a 45-year-old man with a two-month history of a right neck mass. He underwent a complete diagnostic path that highlighted the presence of a parapharyngeal mass associated with the presence of a thyroid nodule suspected to be malignant. The patient underwent surgery (thyroidectomy and removal of the PS mass that was found to be a metastatic node of papillary thyroid carcinoma). The aim of this case is to underline the importance of detecting these kinds of lesions. Nodal metastasis in PS from thyroid cancer is a rare occurrence that is not easily detectable by a clinical examination until the metastasis reaches a considerable dimension. Computed tomography (CT) and magnetic resonance imaging (MRI) permit early identification, but unfortunately, these are not usually employed as a first-level imaging technique in patients with thyroid cancer. The treatment of choice is surgery with a transcervical approach that allows for better control of the disease and of the anatomical structures. Non-surgical treatments are usually reserved for patients with advanced disease, with satisfactory results.

Papillary Thyroid Carcinoma with Extensive Cervical Lymph Node Metastasis and Initial Retropharyngeal Lymph Node Metastasis: A Case Report and Literature Review

Papillary thyroid carcinoma (PTC) is prone to regional lymph node metastasis, which is more common in central lymph nodes and lateral cervical lymph nodes, and retropharyngeal lymph node metastasis (RLNM) is extremely rare. A male with PTC presented with extensive cervical lymph node metastasis and the initial RLNM. After full evaluation by preoperative imaging examination, the patient underwent total thyroidectomy + left central lymph node dissection + left neck lymph node dissection (II III IV V) + left retropharyngeal tumor resection, and the postoperative recovery was good without recurrence long-term complications, and no local recurrence and metastasis were found during one-year follow-up.

Different surgical approaches in retropharyngeal lymph nodes dissection in head and neck cancer: A systematic review

OBJECTIVE

To perform a systematic review of studies analyzing different surgical approaches in the treatment of retropharyngeal lymph node (RPLN) metastases.

METHODS

The study was performed according to the PRISMA guidelines.

RESULTS

Twenty-one studies were included in the review, for a total of 481 patients (median age: 55.8 years; male: n = 279/393, 70.1%). The success rate by type of approach was 100% (n = 233/233), 93.5% (n = 29/31), 95.7% (n = 67/70), 100% (n = 14/14), 100% (n = 82/82), and 100% (n = 51/51) in the transcervical, endoscopic-assisted transcervical, TORS, transoral, maxillary swing and transmandibular cohorts, respectively. The complication rate by type of approach was 11.2% (n = 26/233), 48.4% (n = 15/31), 48.6% (n = 34/70), 14.3% (n = 2/14), 6.1% (n = 5/82) in the transcervical, endoscopic-assisted transcervical, TORS, transoral and maxillary swing cohorts, respectively. Oncological outcomes were reported by 17 studies (n = 404/481; 84%). Overall, after a median follow-up of 28 months (n = 339/481; IQR 23-40.5), no evidence of disease (NED) was found in 238 patients (58.9%), recurrence at the RPLNs in 14 (3.5%), local recurrence in 22 (5.4%), regional recurrence in 23 (5.7%), locoregional recurrence in 16 (4%), distant metastases in 42 (10.4%), death from disease in 36 (8.9%), death from other cause in 23 (5.7%), and death from unspecified cause in 26 (6.4%).

CONCLUSIONS

Further prospective randomized controlled trials are needed to provide direct comparison between different approaches for RPLNs dissection.

Imaging of Treated Thyroid and Parathyroid Disease

The thyroid and parathyroid glands are endocrine structures located in the visceral space of the infrahyoid neck. Imaging plays a critical role in the evaluation of patients with thyroid cancer, both in the pre and posttreatment setting. Disorders of thyroid function, that is, hyperthyroidism and hypothyroidism, are also fairly common, although imaging utilization is less frequent with these conditions. Parathyroid dysfunction results in disordered calcium metabolism. Imaging is frequently applied in the preoperative assessment of these patients undergoing parathyroidectomy; however, routine imaging in the postoperative setting is uncommon. Parathyroid carcinoma is rare; however, imaging may be used in the pre and posttreatment setting.

Metastatic thyroid carcinoma to the parapharyngeal and retropharyngeal spaces: Systematic review with seven newly reported cases describing an uncommon presentation of a common disease

BACKGROUND

Metastatic thyroid carcinoma to retropharyngeal and parapharyngeal (RP/PP) lymph nodes is rare. Literature suggests previous lateral neck dissection (LND) may alter patterns of lymphatic drainage in the neck, predisposing to these less common sites of spread.

METHODS

PRISMA-guided systematic search for all published cases detailing RP/PP metastases of well-differentiated thyroid carcinoma from 1970 to 2019.

RESULTS

Seventy articles were identified and 44 were included, along with seven cases treated at our institution, totaling 239 cases. Cases represented both retropharyngeal (60.7%) and parapharyngeal (39.3%) metastases identified in the initial (27.6%) and recurrent (72.4%) setting.

CONCLUSION

RP/PP metastases generally present in the recurrent setting. RP/PP metastases often represent high-risk disease, and surgical treatment is recommended.

Transcervical dissection of metastatic suprahyoid retropharyngeal lymph nodes from papillary thyroid carcinoma through three anatomical barriers

Papillary thyroid carcinoma (PTC) rarely metastasizes to the suprahyoid retropharyngeal lymph nodes (SRPLNs). Studies on SRPLN metastasis from PTC and a description of the dissection of the SRPLNs via the transcervical approach are rare in the literature. In this study, the cases of six patients diagnosed with PTC with SRPLN metastasis, who underwent dissection of the SRPLNs between 2001 and 2017, were reviewed retrospectively. A transcervical approach was applied for exposure and dissection of the SRPLNs in all patients. All patients were successfully treated by transcervical resection of the metastatic SRPLNs. No patient needed a mandibulotomy or presented severe complications. The median duration of follow-up after dissection of the SRPLNs was 83 months. No recurrence of SRPLN metastasis was identified during follow-up, and none of the patients died of the disease. Surgery might be the best treatment for SRPLN metastasis from PTC. The transcervical route to the retropharyngeal space is through three anatomical barriers, including the submandibular gland, the posterior belly of the digastric muscle, and the blood vessels branching from the external carotid artery and internal jugular vein. Surgical removal of metastatic SRPLNs through the transcervical approach was safe and effective.

Management of Retropharyngeal Lymph Node Metastases in Differentiated Thyroid Carcinoma

Background: Retropharyngeal lymph node metastases (RPMs) from differentiated thyroid carcinoma (DTC) are rare. Treatment includes surgical resection, radioactive iodine (RAI) therapy, or external beam radiation therapy (EBRT). The objective of this study was to describe our experience in the management of DTC-associated RPMs. Methods: Patients diagnosed with a DTC-associated RPM from 1999 to 2018 were identified at our institution, using key search terms in imaging and histology reports. Patient and tumor characteristics were recorded, and patients were grouped according to RPM management: observation, nonsurgical treatment, or surgical resection. The estimated rates of local RPM control, disease-specific survival (DSS), and distant metastasis-free probability (DMFP) were calculated by using the Kaplan-Meier method. Results: Of the 65 patients identified, 53 (82%) had an RPM as a manifestation of recurrent disease. Twenty-five patients (38%) underwent observation, 13 (20%) received nonsurgical treatment (RAI, EBRT, and/or systemic therapy), and 27 (42%) underwent surgical resection. In the observation cohort, all patients had a stable RPM, which in the majority (80%) of cases remained <1.5 cm during the period of observation (median 28 months). Of the 13 patients in the nonsurgical treatment cohort, 3 received RAI therapy, 7 received EBRT, and 3 received systemic therapy only. In the surgical cohort, the median RPM maximum diameter was 2.0 cm (range 0.8-4.2 cm). The size of the RPM was predictive of surgical resection versus observation (p < 0.001). A transcervical approach was employed in 19 patients, and a transoral approach was used in 8 patients. The 5-year rate of local RPM control was 92%. For the whole cohort, the 5- and 10-year DMFP were 72% and 62%, respectively; the 5- and 10-year DSS were 93% and 81%, respectively. Conclusions: DTC-associated RPMs manifest as recurrent disease in the majority of patients. Select patients with a small-volume and nonprogressive RPM may be suitable for observation, whereas surgery is likely warranted in large or progressing RPMs. In general, the presence of an RPM from DTC appears to be associated with aggressive disease.

Preoperative Computed Tomography Changes Surgical Management for Clinically Low-Risk Well-Differentiated Thyroid Cancer

BACKGROUND

In the current guidelines for differentiated thyroid cancer (DTC), computed tomography (CT) of the neck has a limited role. The authors hypothesized that adding CT to the workup of clinically low-risk DTC size 4 cm or smaller changes the surgical management for a portion of patients due to detection of clinically significant lymph node metastases not located by ultrasound of the neck.

METHODS

A prospective cohort of DTC patients at an academic referral center between 2012 and 2016 was reviewed. All the patients with fine-needle aspiration cytopathology results suspicious for malignancy or malignant tumor (Bethesda category 5 or 6, respectively) underwent CT before surgery. Clinically low-risk DTC patients were selected if they had a tumor diameter of 4 cm or less and no evidence for local invasion or suspicious lymph nodes seen on ultrasound. Outcomes focused on alteration of the surgical plan based on CT and correlation with pathology.

RESULTS

The CT findings for 25 (22.5%) of 111 patients with clinically low-risk DTC led to a change in surgical management. Of these 25 patients, 16 (14.4% of the entire cohort) benefited due to the removal of clinically significant lymph node disease not seen on ultrasound. Categorization of the group that had a change in management showed that 6 (85.7%) of 7 lateral neck dissections and 10 (55.6%) of 18 central neck dissections (CND) harbored metastatic nodes larger than 2 mm.

CONCLUSIONS

In the group with clinically low-risk DTC, CT changed surgical management for a substantial number of the patients with clinically significant nodal disease not detected by ultrasound. This highlights the fact that in certain practice settings, adding CT to the preoperative staging may be favorable for the detection of nodal metastasis.

Functional and oncological outcomes after retropharyngeal node dissection for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma frequently metastasizes to central and lateral neck lymph nodes, but metastasis to retropharyngeal lymph nodes (RPLN) is rare.

PATIENTS AND METHODS

We retrospectively reviewed 16 patients with RPLN metastasis of PTC who underwent therapeutic dissection of RPLN metastases.

RESULTS

Among 16 patients, 7 patients underwent RPLN dissection with initial surgery and remaining 9 patients as salvage surgery. RPLN metastasis arose unilaterally in 15 patients and bilaterally in 1 patient. Eleven patients showed temporal dysphagia and four patients showed temporal vocal cord paralysis, but both symptoms eventually recovered in all cases. Two patients with salvage RPLN dissection died of distant metastasis and six patients survived with distant metastasis and/or persistent loco-regional disease. Other eight patients have been alive without disease.

CONCLUSIONS

Although transcervical approach for RPLN metastases of PTC provided acceptable functional and oncological outcomes, half of the patients with RPLN metastasis have had distant metastasis and/or persistent locoregional disease. Indications of surgery for patients with RPLN metastasis need to be performed carefully in consideration of patients' prognosis and quality of life.

An Interesting Case of Retropharyngeal Lymph Nodal Metastases in a Case of Iodine-Refractory Thyroid Cancer

Metastases to cervical lymph node are fairly common in differentiated thyroid cancer. In iodine-refractory disease, the disease may persist in the thyroid bed, cervical lymph nodes, lungs, or the bones commonly. Retropharyngeal lymph nodal involvement in thyroid cancer is unusual and may even be the presenting complaint. We represent a case of iodine-refractory thyroid cancer with retropharyngeal lymph nodal involvement in addition to lung metastases.

Chapter 4 Thyroid Malignancy: Staging and Restaging

Determining the extent of disease is necessary for guiding the management of thyroid carcinomas. Diagnostic imaging, including ultrasound, computed tomography, magnetic resonance imaging, and nuclear medicine scans, plays an essential role in staging and restaging of thyroid carcinomas. This article reviews the approaches and imaging findings for evaluating the primary tumor, regional lymph node metastases, and distant metastases. In addition, potential pitfalls are discussed and depicted.