Ectopic thymus presenting as a solid submandibular neck mass in an infant: case report and review of literature

Ectopic thymic tissue in subglottis of children: evaluation and management

OBJECTIVES

Ectopic thymic tissue in the subglottis is an extremely rare disease that causes airway obstruction. Few cases reported were accurately diagnosed before surgery.

METHODS

A case of a 2-year-old boy with airway obstruction caused by a left subglottic mass was reported. The presentation of radiological imaging, direct laryngoscopy and bronchoscopy, pathology, and surgical management were reviewed. An extensive search in PubMed, EMBASE, Web of Science, Google Scholar, and EBSCO of English literature was performed without a limit of time.

RESULTS

Besides our case, only six cases were reported since 1987. The definitive diagnosis on these patients were made with the findings of pathology, of which, five were ectopic thymus and two were ectopic thymic cysts. Our case was the only one with a correct suspicion preoperatively. Four cases underwent open surgical resection, and two cases underwent microlaryngeal surgery, while one deceased after emergency tracheostomy. No recurrences were found by six patients during the follow-up after successful treatments.

CONCLUSION

Ectopic thymus is a rare condition, infrequently considered in the differential diagnosis of subglottic masses. Modified laryngofissure may be an effective approach to removing the subglottic ectopic thymus and reconstructing the intact subglottic mucosa.

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 thymus as a cause of Horner's syndrome

Ectopy of the thymus is a rare anomaly arising during fetal development, where the thymus does not make a complete decent into the thoracic cavity where it should involute in adolescence. The most common complications of an ectopic thymus include tracheal or esophageal compression presenting in childhood. This is a report of a single case of ectopic cervical thymus identified in a 2-month-old infant presenting with Horner's syndrome. Thymic ectopy should be on the differential when performing a radiologic evaluation of a neck mass when imaging characteristics are similar to thymic tissue.

Ectopic Thymus: An Unusual Case of Subglottic Mass

Objectives:

The aim of our study is to report a case of a child with subglottic thymus that was suspected during diagnostic work-up for severe airway obstruction, excised surgically and confirmed with final histopathological examination. Moreover, we performed a narrative literature review to outline clinical and diagnostic features of this rare condition and to report suggestions for the management of subglottic masses.

Methods:

We report the case of a 7-month-old boy who was admitted to our Pediatric Airway Team Unit due to a history of worsening biphasic stridor and recurrent episodes of upper airway obstruction. The successful diagnostic work-up and a narrative literature of analogous cases of subglottic thymus were reported.

Results:

Ectopic thymus is a very rare condition in which thymic tissue is found outside the normal pathway of its embryonic migration. It usually presents as a cystic or, more rarely, solid mass, showing an indolent course toward spontaneous involution. In some cases, however, it becomes symptomatic exerting compression on surrounding vital structures. Due to its rarity, the initial diagnosis is normally mistaken with inflammatory diseases or malignancies and the definitive diagnosis is only achieved after histological examination of the excised specimen. To our knowledge, only four other cases of subglottic ectopic thymic tissue have been reported in the English literature so far and the diagnosis has never been suspected preoperatively.

Conclusion:

It is mandatory to consider ectopic thymic tissue in the differential diagnosis in children presenting with airways obstruction in order to prevent unnecessary, extensive, and exploratory surgery.

[Ectopic thymus: A rare cause of neck mass in children]

INTRODUCTION

Ectopic cervical thymus (ECT) is a rare embryological abnormality in children. It can be revealed by a compressive neck mass mistaken for a malignant tumor. Through a new case of ECT, we review the embryopathogenesis, diagnostic difficulties and therapeutic features.

CLINICAL OBSERVATION

A 19-month-old girl presented a right cervical mass that quickly increased in size, causing intermittent dyspnea. The physical examination objectified a 6-cm, soft and compressible, painless right cervical tumefaction, extending from the mastoid area to the ipsilateral supraclavicular fossa. The diagnosis suggested based on CT was a cervicomediastinal cystic lymphangioma. The diagnoses discussed based on MRI were a collection of necrotic lymphadenopathy, rhabdomyosarcoma or neurofibroma debris. The mass was surgically excised through a laterocervical incision. A whitish multilobular tissular mass was found, adherent to the neurovascular axis of the neck. Pathological examination concluded in normal ectopic thymus tissue. The postoperative course was uneventful.

CONCLUSION

Although ECT is a rare benign anomaly, it should be considered as a possible cause of a neck mass in children. Surgery is the curative treatment. Before surgery, the presence of a mediastinal thymus must be confirmed to avoid the risk of a total thymectomy in children. MRI is helpful in delineating thymic ectopia compared to the mediastinal thymus.

[A Case of Infantile Cervical Ectopic Thymus]

We report herein on a case of ectopic cervical thymus in a 5-year-old boy and the literature is reviewed. Swelling of the right neck was seen in the patient in his newborn period and it was diagnosed as cystic disease of the neck in a previous hospital at 4 months of age. Ultrasonography (US) and MRI revealed a cervical tumor consisting of a solid component in our hospital, and histopathologic examination showed no evidence of malignancy. The lesion revealed almost no change in size but showed a mosaic pattern on US, whereon the parents agreed to the removal of the tumor. Intraoperatively, the tumor could be easily dissected from the surrounding tissue and resected. The pathological diagnosis was normal thymic tissue. The postoperative course was uneventful and no complication or immunological disorders were seen. A cervical ectopic thymus is a congenital lesion that results from abnormal thymic migration during embryogenesis. Most patients are asymptomatic and the condition is found incidentally. Preoperative diagnosis of cervical ectopic thymus in children is rarely made, so surgical treatment is the definitive means of pathological diagnosis. This disease should be listed in the differential diagnosis for neck masses in children, and should be suspected when the mosaic pattern is detected in the lesion on US.

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.

Cervical thymic cyst in an adult

Cervical thymic cysts (CTCs) are unusual lesions, representing only 1% of cystic cervical masses. Diagnosis of this condition in adults is even rarer. We report a 34-year-old female who presented with asymptomatic progressively growing left-sided neck swelling. Neck ultrasound (US) showed a large cystic lesion with septation, compressing the ipsilateral vessels. Magnetic resonance imaging (MRI) confirmed the US findings. Surgical excision was performed which subsequently showed findings consistent with CTC. CTC in adult is extremely rare, with few reported cases identified in the literature. Thymic gland anomalies in the neck are the consequences of an arrest in the descent of the gland, sequestration of the thymic tissue, or failure of involution. The diagnosis of this condition is rarely done prior to surgical excision. The clinical presentation, radiologic imaging, surgical findings, and histologic appearance are all essential components to make the correct diagnosis of this very rare differential diagnosis of cystic lateral neck swelling.

Cervical thymic cyst mimicking laryngocele

Cervical thymic cysts are nearly 0.3% of all congenital cervical cysts. Thymic cysts are asymptomatic, but they rarely complain of dysphagia or tracheal obstruction symptoms. A soft, mobile, and painless mass increasing with valsalva maneuver directs the diagnosis of laryngocele. There has not been any study in the literature in which thymic cyst presenting like laryngocele. We hereby present a case of thymic cyst mimicking laryngocele that has not been reported so far.

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.

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.

Ectopic cervical thymus: case report and review of pathogenesis and management

Objective:

Ectopic cervical thymus is a rare anomaly, and 50 per cent of cases occur in children. The aim of this report was to remind clinicians of this rare condition, which is part of the differential diagnosis of a paediatric neck lump.

Method:

Case report together with literature review of the pathogenesis and management of ectopic cervical thymus.

Results:

The ectopic cervical thymus is a rare cause of a benign neck mass, and is thus usually misdiagnosed as lymphadenopathy or neoplasia. We discuss its embryology, aetiology, presentation, histopathology, radiology and management, with reference to the reported case.

Conclusion:

Ectopic cervical thymus should always be considered in the differential diagnosis of a paediatric neck lump. The diagnosis can often be confirmed by cytology and radiology prior to surgical excision.

Inspiratory stridor and dysphagia in two newborn infants caused by ectopic thymus tissue

We report two cases of ectopic cervical thymus, a solid thymic lesion, and a thymus cyst causing inspiratory stridor and mild dysphagia in the neonatal period. Because of the rarity of thymic dystopia, the two masses were initially misdiagnosed as more common entities, namely, lymph node enlargement and lymphangioma, respectively. The correct diagnosis was made only after surgical excision and histopathological examination. This case report is completed by a short review of embryogenic development, diagnostic procedures with differential diagnoses, and therapeutic outcome of ectopic thymus.

Solid cervical ectopic thymus in an infant

Cervical ectopic thymus presenting as a neck mass is rare in a neonate. Just more than 100 cases have been reported in the literature with less than 10% occurring in infants. We report a case of solid cervical ectopic thymus in an asymptomatic 2-month-old boy. We review the literature and discuss the embryology, pathophysiology, diagnosis, and management of an infantile ectopic thymus.

Cervical thymic cysts

Thymic cysts are rare embryonic remnants along the course of thymic migration in the neck or the anterior mediastinum which may result in cervical masses in children, often misdiagnosed. We present the experience gained by three European tertiary care medical centers in the treatment of thymic cysts as well as the current data on the embryology, clinical presentation, diagnosis and management of thymic cysts. A retrospective study was carried out in nine patients with thymic cysts during the period 1986-2002 at the departments of Pediatric Surgery of Children's University Hospital "Federico II" and "Santobono" Pediatric Hospital of Naples in Italy and "Aghia Sophia" Children's Hospital of Athens in Greece. All cases were asymptomatic, appearing mainly as masses resembling branchial cyst or lymphatic malformation. Laboratory and imaging investigations were not useful for preoperative diagnosis. In one case the mass extended into the mediastinum. The histological findings of thymic tissue and Hassal's corpuscles in the cystic wall were diagnostic. In all cases, surgery was successful and uneventful. Surgical excision was accomplished by dissection of the cystic masses from the jugular vein, carotid artery and vagus nerve and from the sternocleidomastoid muscle. The presence of a normal thymus in the mediastinum must be documented preoperatively in order to avoid the risk of total thymectomy. If a cervical thymic cyst extends into the normal thymus, attempts should be made to preserve the thymus, especially in younger patients. Thymic cysts should always be included in the differential diagnosis of lateral cervical masses, especially in children.

Ectopic thymic hyperplasia in a patient treated for Burkitt lymphoma

Thymic hyperplasia results from thymic regrowth after atrophy during stressful conditions such as burns, surgery, infection, and chemotherapy. Although thymic lesions are relatively common causes of anterior mediastinal masses, they also can develop in other mediastinal compartments on rare occasions. It is well known that thymic tissue can develop in ectopic intrathoracic lesions. Few cases of ectopic thymus associated with disturbance during thymus embryogenesis have been reported as incidental findings. We report the case of a 4-year-old boy with true thymic hyperplasia from an ectopic thymus after successful treatment for Burkitt lymphoma. This is a rare finding in the differential diagnosis of a middle mediastinal mass in a child following chemotherapy for lymphoma. The diagnosis of thymic hyperplasia from an ectopic thymus can be confirmed only histologically.

Ectopic cervical thymus in an infant

We report a case of accessory cervical thymus presenting as a unilateral neck mass in a 2-month-old boy. Ultrasonography (US) showed a mass isoechogenic to muscle in the left neck. Computed tomography (CT) revealed a well-defined, mildly enhanced mass located anterior to the sternocleidomastoid muscle, anterolateral to the carotid sheath, and posterior to the submandibular gland. On magnetic resonance imaging (MRI), the mass was isointense to muscle on T1-weighted images and hyperintense to muscle on T2-weighted images. Diffusion-weighted images showed relatively low apparent diffusion coefficient (ADC) values, and the mass was slightly enhanced after administration of contrast material. We suspected ectopic thymus, but we could not exclude the possibility of a malignant lesion. Therefore, the tumor was surgically resected. The histological diagnosis was ectopic cervical thymus. Ectopic thymus should be included in the differential diagnosis of a submandibular or cervical mass in infants. US and MRI can provide useful information for the diagnosis of ectopic cervical thymus.

Two cases of ectopic cervical thymus: Case reports and a review of the literature

Ectopic cervical thymic tissue has rarely been reported in the medical literature. However, it should be included in the differential diagnosis of neck masses, and especially for children. This lesion generally occurs in the descent line of the thymus from the angle of the mandible to the superior mediastinum. The preoperative diagnosis of ectopic cervical thymus is seldom considered and this is often misdiagnosed as a possible tumor or as a lymph node. We report here on two cases of ectopic cervical thymus for which the patients underwent complete excision of the masses.

Ectopic thymus presenting as a subglottic mass: diagnostic and management dilemmas

The commonest subglottic mass in infants is a congenital haemangioma, which is usually managed conservatively without a histological diagnosis. Ectopic cervical thymus is rare and usually presents as a cervical mass, with only one case of subglottic ectopic thymus reported to date. Due to its rarity, the diagnosis in most cases relies on surgical excision and histological examination. However, histological diagnosis may not always be easily reached, as is demonstrated in this case report. In this article, an infant with congenital stridor secondary to a subglottic mass is described and the clinical and diagnostic difficulties in its management are discussed.

Aberrant cervical thymus mimicking a cervical mass

A case of a 9-year-old female with suprasternal extension of the thymus mimicking thyroid gland enlargement is described. Ultrasonography successfully established the diagnosis. Aberrant cervical thymic tissue is an infrequently reported cause of paediatric neck masses. It is important to be aware of this entity to prevent anxiety and inappropriate investigation and/or intervention.

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

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.

Sonographic findings in ectopic cervical thymus in an infant

We present the case of a 28-day-old boy with ectopic thymic tissue in the neck. Sonography showed a well-delineated, homogeneous lesion in the left submandibular region that was isoechoic relative to the mediastinal thymus. The lesion had angular margins and lacked a mass effect despite its large size (3 x 2 cm). On power Doppler imaging, arteries with an intermediate-impedance flow pattern were seen entering the lesion from the inferior and lateral margins. On both T1- and T2-weighted MR images, the lesion was isointense relative to the mediastinal thymus and had higher and lower signal intensity than muscle and fat, respectively. A sonographically guided needle biopsy confirmed the diagnosis of ectopic thymus.

Ectopic cervical thymus in a 12-year-old boy: a case report

The case of a 12-year-old boy with ectopic cervical thymus is reported. This is a rare differential diagnosis in cervical tumors in childhood. The clinical symptoms might present as complications; in rare cases malignant transformations have been reported. The diagnosis ectopic cervical thymus can be achieved only histologically. Due to possible malignant transformation, it is mandatory to excise this thymus tumor totally.

Congenital cysts and fistulas of the neck

This retrospective study describes a series of 191 children treated for congenital cysts and fistulas of the neck between 1984 and 1999 in the pediatric ORL Department of La Timone Children's Hospital. Preauricular fistulas and cystic hygromas were not included. The anomalies in this series were classified as either malformations of the midline or malformations of laterocervical region. Malformations of the midline included the thyroglossal duct cysts (n=102) and dermoid cysts (n=21). The most common malformations of the laterocervical region were cysts and fistulas of the second cleft (n=37) followed by those of the first cleft (n=20),those of the fourth pouch (n=7), and thymic cysts (n=4). Diagnosis of malformations of the midline is usually straightforward. However, diagnosis of malformation of the laterocervical region can be problematic. Misdiagnosis often leads to inadequate treatment with recurrence and functional as well as cosmetic sequelae.