|Year : 2022 | Volume
| Issue : 6 | Page : 753-755
Cervical thymic cyst – A rare diagnosis
Jayateertha Joshi1, Abhishek Ganguly1, Chaithra G Ventakataramana2, Sadashiva P Rao3
1 Department of Pediatric Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore, Karnataka, India
2 Department of General Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore, Karnataka, India
3 Department of Pathology, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore, Karnataka, India
|Date of Submission||14-Jan-2022|
|Date of Decision||01-Jul-2022|
|Date of Acceptance||30-Jul-2022|
|Date of Web Publication||11-Nov-2022|
Siva Sundaram Apartment Flat T4, #4 Patalamma Temple Street, Basavanagudi, Bengaluru - 560 004, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Cervical thymic cysts are rare cysts which are seen in the first decade of life in males on the left side. The following is a case of a young female with a painless swelling on the right side of the neck. She was evaluated and underwent exploration of the neck and excision of the swelling.
Keywords: Cervical thymic cyst, ectopic cyst, unusual cervical cyst
|How to cite this article:|
Joshi J, Ganguly A, Ventakataramana CG, Rao SP. Cervical thymic cyst – A rare diagnosis. J Indian Assoc Pediatr Surg 2022;27:753-5
|How to cite this URL:|
Joshi J, Ganguly A, Ventakataramana CG, Rao SP. Cervical thymic cyst – A rare diagnosis. J Indian Assoc Pediatr Surg [serial online] 2022 [cited 2022 Dec 7];27:753-5. Available from: https://www.jiaps.com/text.asp?2022/27/6/753/360971
| Introduction|| |
Thymic cysts are benign lesions of the thymus characterized by thymic tissue within the cyst wall and are <1% of all cervical masses. They are commonly found in the anterior mediastinum and are usually asymptomatic. Although exact incidence is not known, cervical thymic cysts are rare and typically seen in the anterior triangle on the left side. They are more common in males with peak onset at 5–7 years. Ectopic thymic tissue often undergoes hyperplasia in the first decade of life and hence is seen in the pediatric age group. However, due to low incidence, a preoperative diagnosis is rarely established.
| Case Report|| |
This is the report of a 14-year-old female who presented with a painless swelling on the right side of the neck, noticed from 1 week. She had no preceding history of trauma, fever, or any other similar swellings. She had no difficulty in swallowing or neck movements. Examination revealed a 4 cm × 4 cm swelling in the upper part of the anterior triangle of the neck, about 5 cm to the right of the midline which was nontender, reducible, mobile, and firm in consistency. There were no overlying skin changes and no other swellings or lymphadenopathy. Differential diagnoses of lymphatic cyst/laryngocele/branchial remnant/hamartoma were considered. None of these other than laryngocele are usually reducible.
Full blood count done was within normal limits. Contrast-enhanced computer tomography scan of the neck [Figure 1] was done which showed a peripherally enhancing thin-walled lobulated cystic lesion 26 mm × 17 mm × 26 mm in the visceral space at the level of the hyoid bone on the right side. An indirect laryngoscopy was done which however showed normal larynx. Hence, decision was taken to perform a neck exploration under general anesthesia. After proper preparation, the patient was shifted to the operative table.
|Figure 1: CECT neck showing the cystic lesion on the right side. CECT: Contrast-enhanced computed tomography|
Click here to view
The swelling however disappeared after putting the child in supine position with the neck extended using the shoulder roll. This was anticipated as the swelling was reducible on examination and probably was a deep swelling. Hence, on-table ultrasound of the neck was performed to locate the swelling and the placement of incision. Preoperative ultrasound was not done however. Intraoperatively, a cystic lesion was encountered with solid component on the right side of the neck free from the larynx, located just posterior to the upper part of the larynx with a tail of fibro-fatty tissue extending down into the superior mediastinum. The whole lesion was dissected, freed from its attachments, and excised in total.
Grossly, the lesion was cystic with brownish fluid and measured about 4.5 cm × 1.5 cm × 0.8 cm in dimension. On cut section, it showed a pale white nodule with cystic component. Histopathology [Figure 2] revealed squamous epithelial lining of the cyst with underlying thymic tissue composed of lymphoid follicles and Hassall's corpuscles. Cholesterol granulomas with foreign body giant cell reaction were observed in the cyst wall.
|Figure 2: Sections showing squamous epithelial lining of the cyst with lymphoid tissue and cholesterol crystals|
Click here to view
| Discussion|| |
The thymus originates from the third and fourth pharyngeal pouch and descends up to the mediastinum. Hence, thymic tissue may be found along this path as thymic cysts. Cervical thymic cysts are commonly found more on the left side, in males, and in front of the sternocleidomastoid along the embryological line of thymic descent. They can be unilocular or multilocular and may be difficult to differentiate from branchial cleft cysts or lymphatic malformations. Exact diagnosis is usually made postoperatively when thymic elements are visualized within the cyst wall. Cysts have typically brown fluid and are benign. These lesions, though benign, can have mediastinal extension in up to 50% of cases which is a key feature during surgical excision. Two main theories of pathogenesis have been proposed by Speer – persistent thymopharyngeal duct and from Hassall's corpuscles' degeneration.
Complete excision of thymic cysts is the ideal treatment though multilocular cysts may recur due to adhesions in the mediastinum. Incomplete surgical resection can also lead to recurrence.
This report highlights the occurrence of a cervical thymic cyst on the right side in a young female patient with nonspecific clinical and radiological findings (previous reports showing male predominance and classical location on the left side of the neck). In younger individuals, there may be a role for observation rather than urgent intervention. In our case, we got a preoperative CT done and went ahead for exploration. Magnetic resonance imaging (MRI) was not considered in our case as the patient's relatives were not affordable for the same. Other similar cystic lesions would require evaluation in the form of local MRI (for branchial remnants or hamartoma) or lymphangiogram (for lymphatic malformations). With a number of possible cysts in the pediatric age group and the varied presentation of thymic cysts, thymic cysts should always be included in the preoperative differentials for cystic lesions in the neck.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Jindal A, Sukheeja D. Unilateral cervical thymic cyst in a child: A rare case report. J Sci Soc 2016;43:24-6. [Full text]
Sturm JJ, Dedhia K, Chi DH. Diagnosis and management of cervical thymic cysts in children. Cureus 2017;9:e973.
Shenoy V, Kamath MP, Hegde MC, Rao Aroor R, Maller VV. Cervical thymic cyst: A rare differential diagnosis in lateral neck swelling. Case Rep Otolaryngol 2013;2013:350502.
Coran AG, Adzick NS, Krummel TM, Laberge JM, Caldamone A, Shamberger R. Pediatric Surgery. 7th
ed. Philadelphia: Elselvier; 2012. p. 760-61.
Jaiswal AA, Garg AK, Ravindranath M, Mohanty MK. Multiloculated cervical thymic cyst- case report with review of literature. Egypt J Ear Nose Throat Allied Sci 2014;15:129-33.
[Figure 1], [Figure 2]