It is important to know the normal spectrum of radiographic appearance of thymus to avoid misdiagnosis of thymoma or any other thymic lesion.
Knowledge of the normal spectrum of thymic appearances is important to prevent over-diagnosing or underdiagnosing thymic lesions. 
Computed tomography and pathologic correlations of thymic lesion
. J Thorac Imaging 1988; 3: 61-5.
Anterior mediastinal lesions are thymic lesions
, teratomas, and cystic hygromas.
In general, differentiation of lymphoma from other thymic lesions, particularly thymoma, is difficult on the basis of imaging findings alone, and diagnosis may require invasive procedures (15).
Thymic lesions in patients with myasthenia gravis: characterization with thallium 201 scintigraphy.
The rate of unnecessary or nontherapeutic thymectomies carried out according to a previous CT diagnosis is 43.8% (of which 17.1% are thymic hyperplasia cases) which emphasizes the importance of accurate preoperative diagnosis of thymic lesions
It describes clinical and surgical perspectives with comparison to other diagnostic modalities, thoracic and mediastinal anatomy, technical aspects of performing EBUS-TBNA, indications and diagnostic performance, specimen collection and processing, cytological evaluation and adequacy assessment, normal and nonneoplastic components, and pulmonary epithelial neoplasms, nonpulmonary metastatic carcinomas, nonepithelial neoplasms, thymic lesions
and neoplasms, as well as contamination, background material, and artifacts.
Furthermore, after the review of the immunohistochemical studies and comparison with our patient's previous pituitary and thymic lesions
, we excluded the diagnosis of LCH.
It has been suggested that certain fat-suppression MRI techniques, namely chemical shift imaging, are useful in differentiating thymic hyperplasia from other solid thymic lesions
. Chemical shift imaging is acquired using a fast multiplanar T1W spoiled gradient echo fat-suppressed sequence with in- and out-of-phase images (Figure 14).
Regarding this patient's case, prior to MRI evaluation, reasonable differential diagnoses may also have included lymphoma, thymoma or other thymic lesions
, and germ cell tumors.
Since 1901, approximately 90 cases of aberrant cervical solid and cystic thymic lesions
have been reported in the literature and were identified at either surgery or autopsy.[1-3] Nearly two thirds of all reported cases were identified in children younger than 10 years. Ectopic thymic tissue in the neck is rare in patients older than 20 years.