Background: Ectopic thyroid tissue is a rare condition, especially when present inside lateral cervical lymph nodes. Only two similar cases have been reported. Case Presentation: A case of ectopic thyroid tissue in the lymph nodes of the lateral neck in a 34-year-old woman is reported, leading to a challenging differential diagnosis between micropapillary thyroid cancer with skip metastases or recurrent ectopic thyroid tissue. As a definitive diagnosis could not be made based on imaging or cytology, a diagnostic hemithyroidectomy was performed in combination with a total lateral neck dissection to avoid future ectopic thyroid tissue recurrence. Conclusion: The presence of ectopic thyroid tissue in the lateral neck is rare, especially when present within the lymph nodes themselves. Important differential diagnosis with a thyroid malignancy must be made. Benign causes, such as ectopic thyroid tissue, are diagnoses by exclusion.

Keywords: Lymph Nodes; Thyroid Dysgenesis; Thyroid Neoplasms; Diagnosis, Differential; Thyroidectomy; Neck Dissection; Case Report