A rare case report of Ectopic Cervical Thymoma.

The thymus, a lymphoepithelial organ, during the early fetal life originates from the superior neck and descends to the mediastinum. Embryological maldescent may lead to ectopic rests of thymic tissue along the pathway of its descent, neck being the most common site of ectopic thymic rests. Ectopic cervical thymoma is an extremely rare entity, showing a striking female preponderance whereas a mediastinal thymoma has a slight female preponderance. We characterized a case of ectopic cervical thymoma using convential light microscopy and immunohistochemistry in a 40 years old male patient who presented with a neck swelling simulating a thyroid neoplasm clinically.