Published online Sep 6, 2024. doi: 10.12998/wjcc.v12.i25.5646
Revised: April 24, 2024
Accepted: May 27, 2024
Published online: September 6, 2024
Processing time: 127 Days and 7.1 Hours
We point out the issue of differential diagnosis regarding the finding of ectopically localised thymic tissue (a thymic cyst) in the neck. Thymic tissue can be found anywhere along its developmental tract of descent, from the angle of the mandible to the upper mediastinum. Disruption of the thymic descent can result in ectopically/abnormally localised islets of accessory thymic tissue, which may undergo cystic changes, as described in a case report by Sun et al. This anatomical variation of the thymus may be clinically misinterpreted as a neoplasm or other congenital anomalies as a branchial cyst, lymphatic malformation or cystic hygroma. The present editorial focuses on the challenge of establishing a diagnosis of ectopically localised tissue of thymus often presented as a lateral cervical mass, especially in the case of cystic variation/degeneration of this thymic tissue. We summarise hypotheses on the origin of such congenital cervical thymic cysts from the point of view of evolutionary history and embryology. We also discuss lesser-known facts about the anatomy, histopathology and developmental biology of the thymus as one of the most enigmatic organs in the human body.
Core Tip: In this editorial, we comment on a case report by Sun et al, entitled: Multilocular thymic cysts can be easily misdiagnosed as malignant tumor on computer tomography. We focus specifically on the pertinence of establishing a diagnosis in clinical practice of the ectopically localised tissue of thymus, especially in the case of cystic variation of this thymic tissue. We also summarise lesser-known facts about the anatomy, histopathology and developmental biology of the human thymus as one of the most enigmatic organs in the human body.