Cystic lymph node metastasis of papillary thyroid cancer: clinical facts

The therapy planning for cystic cervical lesions is dizzying. Although it is mostly a benign disease, it can also be a cystic lymph node metastasis with the origin of papillary thyroid cancer (PTC).

Included were all patients with histological confirmed PTC, who underwent a thyroid resection from January 2012 to December 2017 (N.=680). Analyzed were demographic data including family history and radiation exposure, preoperative workup including thyroid ultrasound and laboratory test of the TSH value complimented by fine-needle aspiration in case of suspected malignancy, and clinicopathologic features. This study aimed to specify preoperative findings and patients' clinical presentation with cystic lymph node metastasis of PTC.

In 0.7% (5/680) of all patients with PTC a cystic cervical lesion was histologically confirmed as cystic lymph node metastasis. Preoperatively, only two of these patients were suspected of lymph node metastasis with unknown origin. In three patients, the resected cystic lymph node metastases were the only lymphatic metastasis. Interestingly 80% (4/5) of the patients suffered from papillary microcarcinoma (MPTC).

Cervical cystic lesions may be challenging in diagnostics and therapy. Although the recommended thyroid ultrasound may detect no pathological findings, a papillary microcarcinoma can be the primary tumor.