Cervical thymic cysts

Congenital cystic neck mass of thymic origin

Neck masses are frequently seen in children. The differential diagnosis includes infectious, congenital and neoplastic lesions. We report a case of rare thymic neck mass in a boy in his middle childhood presented with a history of a left anterolateral neck mass not associated with fever, dysphagia or shortness of breath. The radiographic evaluation showed a picture of a thymopharyngeal duct cyst. Thymic remnant and thymopharyngeal duct cyst are caused by the failure of obliteration and might appear as a lateral neck mass in children. The most effective treatment for a thymopharyngeal duct cyst is total surgical excision. This particular case highlights the importance for clinicians to have a high index of suspicion for a broad differential diagnosis when evaluating paediatric patients who present with neck mass. Additionally, we emphasise the importance of consistently considering thymopharyngeal cyst as differential diagnosis.

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.

An Uncommon Case of Cervical Thymopharyngeal Duct Cyst

Thymopharyngeal duct cyst is one of the most uncommon benign cervical lesions encountered in the paediatric population. Due to its rarity, it almost always escapes a correct preoperative diagnosis and is usually misdiagnosed as a branchial cyst or lymphangioma. Furthermore, although located at the neck it may present with retrosternal or mediastinal extension. In this case report here we present a case of a young boy with a right cervical mass, diagnosis of thymopharyngeal duct cyst was confirmed during histopathological examination of the excised specimen. Furthermore, preoperative ultrasonography and MRI did not detect the thin cord and the lower part of the lesion, which rendered operative treatment more demanding. Apropos to these findings, we reflect on the crucial points of awareness that affect the diagnostic and surgical process of this lesion.

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: a case report

Cervical thymic cysts are rare lesions often misdiagnosed clinically as branchial cyst. Here we report a rare case of multiloculated thymic cyst in a young 8 year old male child on the left side of the neck. Histopathology of the excised cyst revealed mural nodules of thymic tissue with prominent Hassal's corpuscles associated with multiloculated cyst. This case is presented here for its rarity. It should be included in the differential diagnosis of neck masses in children.

Cervical thymic cyst presenting as a possible cystic nodal metastasis of papillary carcinoma in a 53-year-old man

Cervical thymic cysts are rare embryonic remnants that develop along the course of thymic migration in the neck. They usually occur during infancy and childhood, and they are extremely rare in adults. We report a case of cervical thymic cyst in a 53-year-old man. The patient presented with a small mass of the thyroid gland and a cystic mass at the left level II area of the neck. On histopathology, the thyroid mass was identified as a papillary carcinoma and the left-sided neck mass was diagnosed as a cervical thymic cyst lined with nonkeratinizing, flattened squamous epithelium. The cyst wall contained atrophic thymic tissue composed of lymphoid cells, epithelial cords, and Hassall corpuscles. Although it is rare, cervical thymic cyst should be considered in the differential diagnosis of a lateral cystic neck mass in an adult.

Cervical thymic cysts in adults

BACKGROUND

Three types of cervical thymic anomalies have been described: ectopia, thymic cyst, and thymoma. Thymic cysts are very rare causes of benign neck masses in adults and are usually not diagnosed before surgery. Their prevalence is less than 1% of all cervical masses, and they are usually noted in childhood. We systematically reviewed the literature concerning cervical thymic cysts (CTCs) in adults.

SUMMARY

We identified 36 adult patients with a CTC. Our analysis included age, gender, cyst size, location, type, symptoms, time from cyst appearance, treatment, pathology, and follow-up. The male/female ratio was 4/5, the mean age was 36 years. Most of the cysts were asymptomatic masses diagnosed by pathology. In only one case did the differential diagnosis include a thymic cyst. Surgery should be considered the treatment of choice, but the size and location of the lesion and its relationship to nearby vital structures should be defined as clearly as possible preoperatively. Excision can be made via a transverse cervical incision. It may be a demanding procedure because of the close anatomical relationship of the CTCs with the carotid sheath and major nerves of the neck (recurrent laryngeal nerve, glossopharyngeal nerve, hypoglossic nerve, and phrenic nerve), particularly if there is adherence of the CTC with those structures.

CONCLUSIONS

CTCs are uncommon lesions causing neck swelling and are often misdiagnosed preoperatively. Surgical excision and histological examination of the specimen usually makes the diagnosis. The existence of normal thymus gland in the mediastinum should be confirmed intraoperatively, but this is not critical in adult patients. A CTC should be included in the differential diagnosis of cervical cystic masses.

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.