Solid cervical ectopic thymus in an infant

Diagnosis and management of ectopic cervical thymus in children: Systematic review of the literature

BACKGROUND/PURPOSE

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.

METHODS

Systematic review of the literature (1997-2020) using PRISMA guidelines.

RESULTS

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.

CONCLUSIONS

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.

Ectopic Cervical Thymus: A Common, yet Rarely Symptomatic Pediatric Neck Mass

Ectopic thymic tissue is an unusual finding that is generally asymptomatic. We present a case series of five pediatric patients with cervical ectopic thymuses. In two patients, the ectopic thymic tissue was symptomatic, and in three patients, it was an incidental finding. We highlight the need to include this anomaly in the differential diagnosis for a pediatric neck mass. We also propose observation, rather than surgical excision, as the treatment of choice for asymptomatic cervical ectopic thymus.

Ectopic cervical thymus in children: Clinical and radiographic features

OBJECTIVES

Ectopic thymus is rare and can be a diagnostic challenge. This study evaluated the management of children radiographically diagnosed with ectopic cervical thymus.

METHODS

A retrospective review of 100 patients was performed. Data related to clinical presentation, radiological imaging, pathology, and management were collected. Changes in lesion volume were tracked over time. Clinical characteristics were compared based on lesion location in the neck using analysis of variance modelling.

RESULTS

There were 115 lesions with radiographic features of ectopic cervical thymus (15 children had bilateral lesions). Diagnosis was based on ultrasound in 98% of patients, magnetic resonance imaging in 18%, and computed tomography in 11%. Mean (SD) follow-up duration was 2 (2.2) years. Forty-four percent (51/115) of lesions involved the thyroid gland, 29% (33/115) were in the central neck but separate from the thyroid, 18% (21/115) had mediastinal extension, and 8% (9/115) involved the submandibular region. Location was unclear for two patients. Submandibular lesions were on average 12.4 cm³ larger (95% CI, 8.2, 16.6) than mediastinal lesions at diagnosis, P ≤ .001. Volume of thymic tissue decreased over time, from a mean (standard deviation [SD]) volume of 4.3 cm³ (9.2) at initial ultrasound to 2.7 cm³ (6.1) at final ultrasound (paired t-test, P = .008). Only two patients required surgery: one for compressive symptoms, and the other to rule out malignancy.

CONCLUSION

Ninety-eight percent of children with ectopic cervical thymus were managed conservatively without issues. We propose a classification system based on location to ease communication among clinicians and to help follow these lesions over time.

LEVEL OF EVIDENCE

4, case series Laryngoscope, 130:1577-1582, 2020.

[Ectopic thymic tissue and ectopic thymic tumors]

Ectopic thymic tissue outside its core position in the antero-superior mediastinum is quite common owing to the complexity of embryonal thymus development, whereby reported prevalence values (1 to 90%) are heavily dependent on the method of investigation and the intensity of the workup. The debated prevalence and relevance of ectopic thymic tissue and its accessibility underlie the ongoing discussion whether modern, minimally invasive thymectomy strategies can match the proven benefit of the radical transsternal thymectomy procedure for the treatment of Myasthenia gravis. In this context, the following article covers the etiology, prevalence, and location of normal-looking, reactive, and neoplastic ectopic thymic tissue. Furthermore, ectopic tissues and tumors inside or adjacent to the thymus are mentioned.

Bilateral ectopic cervical thymus presenting as a neck mass: Ultrasound and magnetic resonance imaging

Ectopic cervical thymus (ECT) is a rare cause of neck mass in the pediatric age group. It is extremely uncommon in infants. Overall more than 100 cases have been reported in the literature, though fewer than 10% involved infants. Furthermore, ECT is usually unilateral and more frequently seen in men than in women. Ultrasound (US) is the preferred initial imaging modality, especially in pediatric neck masses given its wide availability, low cost and lack of radiation exposure. US can show the location, extension, and echotexture of the ECT. Magnetic resonance imaging (MRI) can be performed to verify the diagnosis and confirm communication between the ECT and the mediastinal thymus. Diffusion restriction can aid diagnosis when seen in a neck mass similar to that in the mediastinal thymus. Herein is described a case of bilateral ECT in a 2-month-old boy with associated US and MRI findings.

Ectopic cervical thymus: a clinicopathological study of consecutive, unselected infant autopsies

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Retropharyngeal thymus and parathyroid gland: a case report

Cervical ectopic thymus occurs when thymic tissue arrests during its embryologic descent through the neck to the upper mediastinum. Most often it presents as an asymptomatic neck mass. Rarely does it present with airway compromise, particularly in neonates. A neonate presented with a retropharyngeal mass causing dynamic upper airway obstruction, mimicking a venolymphatic malformation. Ultimately this proved to be aberrant ectopic thymus with an associated parathyroid gland. While there have been isolated reports of thymus or parathyroid in the retropharyngeal space, none of the prior reports found both within the same patient.

Ectopic cervical thymus associated with infant death: 2 case reports and literature review

An ectopic cervical thymus is a rare congenital anomaly that can be located anywhere along the developmental pathway of thymic descent. Most lesions manifest as a cystic mass and have an indolent course. Two fatal cases associated with ectopic cervical thymus in the form of a solid mass are presented in conjunction with a review of the clinicopathological characteristics of the solid form. This report emphasizes the importance of considering a diagnosis of ectopic cervical thymus in infants with neck masses, with or without obstructive symptoms, to prevent possibly fatal outcomes.

Ectopic Thymus Presenting as a Retropharyngeal Mass: Surgical Approach

Cervical ectopic thymus is a rare cause of solid neck masses in children. Most children are asymptomatic, but some may present with a palpable neck mass, with or without compressive symptoms. Cervical ectopic thymus is often discovered incidentally and mistaken for an infection or neoplasm. We present the case of an infant with retropharyngeal ectopic thymus and describe our intraoral surgical approach.

Clinical management of cervical ectopic thymus in children

OBJECTIVE

Cervical ectopic thymus (CET) is an extremely uncommon etiology of a neck mass in an infant. The aim of this study was to study and analyze the clinical manifestations, management principles, and pathological diagnosis of CET.

METHODS

From 1995 to 2010, a total of 25,237 cases of head and neck lesions were treated in the Department of Oral and Maxillofacial Surgery, Shanghai Ninth People's Hospital. Among these huge numbers of lesions, there were only 3 cases of pathological-diagnosed CET presenting as neck masses. These 3 rare cases were interesting, and here, we report their clinical management and pathological diagnosis.

RESULT

Three patients had a pathological diagnosis of CET. Their ages ranged from 4 months to 4 years. Clinically, all 3 patients presented with a painless neck mass and received surgical resection. Pathological diagnoses are based on hematoxylin and eosin and immunohistochemical staining.

CONCLUSION

Painless swelling or neck mass is the major complaint for CET. Radiologic imaging can help determine the extent of the mass and relationship with adjacent structures. Surgery with frozen section remains the main method for pathological diagnosis and management.

[Mediastinal tumors: introduction]

Mediastinal tumors are relatively uncommon, usually incidentally discovered on a chest X-ray in asymptomatic patients. Young adults are particularly concerned. Mediastinal masses represent a group of heterogeneous histological type cell. A definite diagnosis is essential leading to an adequate prompt therapeutic strategy when either benign disease or aggressive malignant tumor is conceivable. Indeed the therapeutic management of such tumors could be strictly medical, requiring exclusive surgical approach or includes a multimodal treatment. Clinical examination and imaging are important tools in the diagnostic approach. However the specific diagnosis could be complex and requires histological confirmation by an experienced pathologist after examination of large biopsies of the tumor. Several investigations, including surgical invasive exploration, should be quickly requested in order to achieve a final diagnosis and refer patients in an adequate therapeutic scheme without delay. The aim of this article is to point out the available diagnostic tools in mediastinal masses, including surgical approach, and to identify the role of surgical resection in specific subtypes.