To know the embryological origin and the period of normal involution of the thymus.
To know the differential diagnosis of masses that can simulate tumors but that in reality are regions of ectopic thymus.
Exposure of several cases related to the thymus and associated derived masses.
The thymus is an organ displayed in the paediatric population that can lead to errors when it is in an ectopic location,
leading to misinterpretation of the images obtained.
In the embryo,
each lobe of the thymus can leave remains in its migration route from the pharynx to the mediastinum.
The ectopic thymic tissue may be cystic or solid.
Knowing the existence of this pathology matters for the differential diagnosis with other cervical cystic masses,
such as lymphatic malformations ("lymphangiomas"),
neoplasias or vascular malformations,
Findings and procedure details
The thymus arises from the third and fourth pharyngeal pouches in the sixth week of gestational life 1.
It is in the course of the seventh week when the thymic nuclei migrate medially and caudally,
forming the so-called thymsopharyngeal conduit,
until its final location that will take place in the anterior portion of the mediastinum 1,2.
The accessory ectopic thymic tissue can appear at any point of the path of the thymsopharyngeal duct,
which extends from the mandibular branch-angle to the cranial portion of the...
Before a solid or cystic mass of cervical location,
mainly on the left side,
the diagnostic possibility of ectopic thymic tissue must be taken into account,
and the mistake of thinking about malignant tumor pathology,
which is the most frequent (more rarely the ectopic thymic tissue goes into other locations than the cervical).
In addition to histology,
which provides the diagnosis of certainty,
imaging tests have a very important role.
The radiologist must know the possible variations in the position and appearance of the normal...
The thymus: a comprehensive review.
Erratum in: Radiographics.
Otto and A.
Pediatric chest radiographs: comon and less common errors. American Journal of Roentgenology 2016 207:4,
Superior cervical extension of the thymus: a normal finding that should not be mistaken for a mass.