Cervical ectopic thymus masquerading as metastatic thyroid papillary carcinoma

Cervical ectopic thymus (CET), a common embryological anomaly detected incidentally at autopsy, is rarely described in clinical patients. Furthermore, aberrant cervical thymic tissue is an infrequently reported cause of paediatric neck masses. We report a 12-year-old female presenting with multinodular thyroid swelling since seven years of age. FNAC revealed adenomatous goitre with suspicious cystic papillary neoplastic foci, for which she underwent total thyroidectomy along with excision of a nodular swelling near the lower pole of the right thyroid lobe which was per-operatively suspected to be a lymph node. Histopathological examination revealed a follicular variant papillary carcinoma of the thyroid with background thyroiditis, and a nodule of ectopic thymic tissue. Though the presence of CET is rare, one should be aware of this entity, especially in children because it may be confused with lymph node metastasis which may lead to morbid radical neck dissection.