Cervical ectopic thymus: a case report and review of the literature

doi:10.1016/S0165-5876(02)00210-0

International Journal of Pediatric Otorhinolaryngology

Volume 66, Issue 1, 21 October 2002, Pages 77-80

https://doi.org/10.1016/S0165-5876(02)00210-0 Get rights and content

Abstract

Ectopic cervical thymic tissue is rarely reported in medical literature, but it should be included in the differential diagnosis of neck masses, especially in children. The authors present the case of a young male with a soft right mid-cervical mass. The patient underwent complete excision of the lesion and histological examination showed an ectopic thymic cyst. The embryological development, clinical presentation and management of ectopic thymic lesions are discussed together with a review of the literature.

Introduction

Ectopic cervical thymic tissue is a rare cause of neck masses. It may be found at any level of the pathway of normal thymic descent, from the angle of the mandible to the superior mediastinum. Seldom considered in the differential diagnosis of neck masses, its presence is often revealed by pathologic examination of an excised specimen. Adolescents and children comprise the majority of the typically asymptomatic patients. As such, the presence of a mediastinal thymus must be confirmed prior to the surgical resection of a neck mass to prevent inadvertent total thymectomy with possible negative effects on the developing immune system. We report the clinical presentation, diagnostic evaluation and therapeutic management of one case of ectopic cervical thymic tissue, accompanied by a short review of the relative literature.

Section snippets

Case report

A 6-year-old child was referred to the Otolaryngology Clinic of S. Orsola-Malpighi Hospital, Bologna, Italy, for the evaluation of a large right mid-cervical mass with the suspicion of lymphadenopathy. The mass was asymptomatic and was noted by the parents in conjunction with a previous upper respiratory tract infection. Although the patient followed an antibiotic therapy regime, the lesion failed to change significantly. The family history and past medical history were unremarkable. Physical

Discussion

Cervical thymic anomalies may occur as a consequence of an arrest in descent during the 9th week of embryonic growth, a sequestration of thymic tissue during descent or a failure of involution [1], [2], [3], [4]. Of the more specific origins proposed [5], the two favored theories for the development of cervical thymic cysts are the persistence of thymopharyngeal ducts (congenital) and the degeneration of Hassall's corpuscles within ectopic thymic remnants (acquired) [6].

A cervical thymic cyst

Conclusion

Ectopic cervical thymus cysts are uncommon but should be included in the differential diagnosis of neck masses, especially in the young. Such anomalies are rarely diagnosed pre-operatively and can be easily confused with other neck lesions. Once diagnosed, surgery is the definitive treatment if the mass is symptomatic and cosmetically unbecoming. Prior to surgery, the presence of a mediastinal thymus should be confirmed to prevent the risk of a total thymectomy. The prognosis after removal of

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Cited by (52)

Diagnosis and management of ectopic cervical thymus in children: Systematic review of the literature
2021, Journal of Pediatric Surgery
Citation Excerpt :
After the removal of duplicates, a total of 313 full-text journal articles were retrieved. Of these, 71 contained adequate data on ECT in children and were therefore included in the final review [4–8,10–13,15–76]. These included both case series and case reports.
Ectopic cervical thymus (ECT) is a rare cause of neck swelling in children. Our aim was to evaluate the diagnostic and management challenges of this condition.
Systematic review of the literature (1997–2020) using PRISMA guidelines.
A total of 192 cases of ECT were identified. Forty-two cases (4 studies) were excluded because of insufficient data resulting in 150 cases (7 bilateral) in a total of 143 patients. ECT presented as a solid mass in 71 cases (10 incidentally found at autopsy, 33 conservatively managed and 28 excised) and as a cystic mass in 79 cases (all excised). A total of 165 imaging studies in 123 patients were performed (65 ultrasound scans (USS), 51 magnetic resonance imaging (MRI) scans and 49 computer tomography (CT) scans). ECT was diagnosed by imaging in 18.7% (23/123) of patients. Fine needle aspiration cytology or incisional/needle biopsy were performed in 16% (23/140) cases; a correct diagnosis of ECT was obtained in 52% (12/23) of those cases. There were no reports of malignancy in 143 specimens analysed. A normal mediastinal thymus was absent in 2.5% (1/40) of patients investigated.
ECT is a benign and relatively rare condition in children that is seldom diagnosed on imaging before tissue sampling or surgical excision. ECT might be the only active thymus in 2.5% of cases and careful consideration should be taken prior to its excision in young children. We recommend that ECT should be considered in the differential diagnosis of neck masses in children. Conservative management might be appropriate in selected cases and the presence of a normal mediastinal thymus in the thorax should be investigated before planning surgical excision.
The paediatric thymus: recognising normal and ectopic thymic tissue
2021, Clinical Radiology
Citation Excerpt :
Although most patients with ectopic thymus are asymptomatic, there are reported cases of ectopic thymus causing dyspnoea, stridor, hoarseness, and dysphagia.10,11,24–26 The recommended management of ectopic thymic tissue is “watchful waiting” anticipating thymic involution unless the patient is symptomatic with dysphagia and/or severe respiratory symptoms; however, due to diagnostic difficulty, most reports of ectopic thymus in the literature were confirmed postoperatively.7,24,27–30 The thymus can undergo acute involution with reduction of thymic volume in response to stressful biological conditions, which include chemotherapy, systemic corticosteroid treatment, and malnutrition.1
The appearance of the paediatric thymus changes as the normal process of thymic involution occurs. Thymic tissue may be orthotopic within the anterior mediastinum or ectopically located along the course of its embryological development. The variable appearance of orthotopic and ectopic thymic tissue in children on imaging studies may lead to misinterpretation of the normal thymus as pathology. Recognition of normal thymic tissue can mitigate unnecessary further diagnostic testing and patient anxiety.
In this review, we discuss the embryological development and anatomical variants of normal thymus, and demonstrate the multimodality imaging features of the normal thymus in children, including positron-emission tomography, and diffusion-weighted imaging and in- and opposed-phase imaging on magnetic resonance imaging. We demonstrate the normal thymus mimicking pathological processes and discuss features that distinguish normal thymus, including thymic rebound hyperplasia, from pathology.
Cervical thymic cyst: A rare cause of neck mass in a female adolescent
2020, Journal of Pediatric Surgery Case Reports
Cervical mass in a 3-year-old child: raising awareness of an unusual diagnosis
2018, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Citation Excerpt :
CETs are found on the left side in more than two-thirds of patients. These masses are often located anteriorly and beneath the sternocleidomastoid muscle and usually extend into the retropharyngeal and carotid space, as in our patient.6 CT findings in patients with CETs may reveal a homogeneous mass with intimate attachment to the carotid sheath.
Cervical thymic cysts
2017, Operative Techniques in Otolaryngology - Head and Neck Surgery
Citation Excerpt :
A babcock or other gentle soft tissue grasper can be used to grasp the cyst wall and provide counter traction to blunt dissection. Other structures that can frequently be attached or adjacent to the cyst include the pyriform sinus, the SCM muscle, the retropharyngeal space, the thyroid, and the parathyroids.34,35 Regardless of where the mass is located, care needs to be taken using blunt dissection techniques to remove all thymic tissues without violating the capsule.36
Thymic cysts are rarely occurring benign neck masses, most frequently seen in children. They are remnants of the third and fourth branchial pouches. They may occur at any point along the thymic tract, though they have a predilection for the left side of the neck, often deep in the neck. Patients often present with compressive symptoms. Treatment is surgical excision. Care must be taken, however, to confirm the presence of thoracic thymic tissue before excision of this neck lesion. On histology, they are defined by the presence of thymic parenchyma and Hassal corpuscles in the cyst wall.
Ectopic cervical thymus: A clinicopathological study of consecutive, unselected infant autopsies
2014, International Journal of Pediatric Otorhinolaryngology
An ectopic cervical thymus (ECT) is regarded as a rare congenital anomaly; therefore, the optimal diagnostic and therapeutic strategy remains a debatable matter. We designed a study to elucidate the clinicopathological characteristics of ECTs in consecutive, unselected infant autopsies, to help guide case management.
We searched for ECTs in all of the 21 consecutive, unselected infant autopsy cases performed at our institution over a period of 3 years, and all ECT consensus diagnoses were confirmed by histological examination. The following clinical characteristics were evaluated in cases with ECTs: age, gender, birth week and weight, clinical symptoms due to the ECT(s), position on discovery of death, cause of death, ECT contribution to the cause of death, and concomitant congenital disorders. The anatomical features evaluated included the location, number, size, color, shape, and margins of the ECTs, and the presence of a mediastinal thymus. Histological findings of the ECT(s) and the mediastinal thymus were compared within each individual. Fusion of the parathyroid and the ECT was also investigated histologically. Spearman's rank correlation coefficient (ρ) and the corresponding P value were calculated to determine if there was an association between ECT diameter and age.
We detected 10 ECT lesions in seven cases (33%) among the 21 infant autopsy cases. The ECT cases involved five boys and two girls, with ages ranging from 1 day to 4 months. There were no reports of a positive family history of sudden death or antemortem clinical symptoms due to ECT in any of the cases. The ECTs were considered incidental regarding the cause of death, with the exception of one case that was extremely rare. Most ECTs were localized to the inferior thyroid, ranging from 0.4 to 1.9 cm in size. Size demonstrated a significant negative correlation with age (ρ = −0.75 and P = 0.034).
This study revealed that ECT is an essentially benign anomaly that occurs frequently during the development of the thymus, and may disappear over the first few years of life. These results suggest a conservative approach to the management of ECTs would be appropriate.

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Case reportCervical ectopic thymus: a case report and review of the literature

Abstract

Introduction

Section snippets

Case report

Discussion

Conclusion

Am. J. Surg.

Int. J. Pediatr. Otorhinolaryngol.

Am. J. Surg.

Am. J. Surg.

Int. J. Pediatr. Otorhinolaryngol.

Int. J. Pediatr. Otorhinolaryngol.

Case report
Cervical ectopic thymus: a case report and review of the literature