A 29-year-old women presents with primary intrathyroidal papillary thyroid carcinoma (BRAF VE1 positive) with morphologically recognizable metastases to cervical lymph nodes (BRAF VE1 positive) as well as a focus of bland-appearing thyroid follicles within the capsule of a level II lymph node (BRAF VE1 negative). There exist various theories regarding the possible developmental origins of "benign" intranodal thyroid tissue in the lateral neck. While the true nature of the bland follicles may not be definitively resolved in this case, these findings are suggestive that they do not represent metastasis from the main papillary thyroid carcinoma. Additional insight into this unusual phenomenon may be gathered by more specific clonal analysis of these microscopic foci.
Keywords: BRAF; immunohistochemistry; lateral aberrant thyroid; lymph node metastasis; papillary thyroid carcinoma.