Axillary lymph node metastasis in recurrence of papillary thyroid carcinoma: a case report

Papillary thyroid cancer usually metastasizes to regional lymph nodes and to distant sites such as lungs and bones. We report a case of axillary lymph node metastasis as a result of recurrence of papillary carcinoma in a 62-year-old woman with papillary thyroid cancer extending locally beyond the thyroid capsule. Six years after initial surgical treatment, a lymph node metastasis in the left axillary region was diagnosed with positron tomography. To our knowledge, only one previous case of confirmed axillary metastasis of thyroid cancer has ever been reported. These two cases provide some evidence that thyroid carcinoma may exceptionally spread to axillary lymph nodes. Hypotheses that may account for such unusual localization include hematogenous dissemination or retrograde dissemination to regional lymphatic channels. Thus, when recurrence of thyroid carcinoma is considered, careful clinical examination of the axilla is recommended. Furthermore, thyroid carcinoma must be considered in the differential diagnosis of an axillary mass, especially when breast cancer is ruled out.