Background: Parapharyngeal lymph node (PPLN) metastasis from thyroid carcinoma is rare. We describe the clinical features, diagnosis, and surgical treatment of this condition.
Methods: Twenty-five patients with PPLN metastasis from thyroid carcinoma were treated at our institution from January 1999 to December 2010, including 22 patients with papillary carcinoma, two with medullary carcinoma, and one with follicular carcinoma. Of these, 16 had a history of surgical treatment prior to PPLN metastasis. Of the nine patients without a history of surgical treatment, five had widespread cervical lymph node metastases and four had occult papillary thyroid carcinoma. PPLN metastasis was diagnosed by enhanced computed tomography in 22 cases.
Results: Resection of metastases was performed via a transcervical approach in 23 patients and a transmandibular approach in two patients. After a median follow-up time of 31 months (range: 6 - 130 months), nine patients developed distant metastases, and six of these died of their disease. The 5-year survival rate was 63.8%.
Conclusions: PPLN metastasis from thyroid carcinoma may occur in patients: with previous neck dissection, with widespread metastases to cervical lymph nodes prior to initial treatment, and with occult thyroid carcinoma. Enhanced computed tomography is helpful for diagnosis in the first two presentations. Surgical resection remains the mainstay of treatment for this disease. PPLN metastasis has a tendency to be associated with distant metastases and a poor prognosis.