Axillary Lymph Node Metastases From Papillary Thyroid Carcinoma: A Case Presentation and Review of the Literature

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer.While it is generally non-aggressive, it commonly metastasizes to the cervical lymph nodes.Distant metastases, and specifically those to the axillary lymph nodes however, are very rare.Here we present the case of a 78-year-old woman with a history of PTC requiring total thyroidectomy in 2001, who presented to the emergency room with an enlarging neck mass measuring 13 cm.Fine needle aspiration revealed recurrent metastatic PTC, which was treated with a lateral neck dissection.Five months post-operatively, the patient was found to have a persistent submental mass, new right-sided neck enlarged lymph nodes, and enlarged bilateral axillary masses.While the axillary masses were originally suspected to be the result of a new-onset breast malignancy, biopsy revealed that the axillary masses were PTC metastases to the axillary lymph nodes.The patient subsequently underwent neck dissection and bilateral axillary dissections.Post-operatively, she is planned to undergo radiation therapy and will follow-up with positron emission tomography scans every six months to evaluate for any new growth.This is one of few cases demonstrating axillary lymph node metastases of PTC.Given the lack of direct lymph drainage from the thyroid to the axillary lymph nodes, more research is necessary to determine the exact mechanism of spread and best treatment approach.