Cervical thymic cysts: CT appearance of two cases including a persistent thymopharyngeal duct cyst

Differentiating thymoma from thymic cyst in anterior mediastinal abnormalities smaller than 3 cm

Background

Computed tomography (CT) screening for lung cancer has led to frequent findings of small anterior mediastinal masses. It is very hard to distinguish small thymomas from thymic cysts. The objective of this study was to develop a clinical model for predicting small thymomas (<3 cm) in asymptomatic patients.

Methods

Patients who underwent thymectomy for anterior mediastinal masses between 2004 and 2016 were included. All preoperative CT scans (pre- and post-enhanced) were retrospectively reviewed. Size, location, contour, shape, presence of calcification, and enhancement [Hounsfield units (HU)] were evaluated. A nomogram was built based on the predictive factors. For external validation, patients undergoing thymectomy in 2017 were enrolled and thymoma prediction was computed using the proposed nomogram.

Results

The study population consisted of 43 patients with thymoma and 57 with thymic cyst. The multivariable analysis identified a lobulated contour and a large difference in HU between post- and pre-enhancement as predictive factors of thymoma. These factors were included in the nomogram, which showed 95% (19/20) power for predicting thymoma after external validation.

Conclusions

This clinical model can be used to predict thymoma in patients with small, asymptomatic thymic abnormalities on CT screening.

Multislice computed tomography performance in differential diagnosis of high-density thymic cyst and thymoma in lesions less than 3 cm

Background

This study was conducted to evaluate the performance of multislice computed tomography (MSCT) to diagnose high‐density thymic cysts and thymomas in lesions measuring < 3 cm.

Methods

The records of 42 patients admitted to Ningbo No. 2 Hospital with an anterior mediastinal mass (diameter < 3 cm) suspected of carcinoma originating from the thymus were retrospectively analyzed. All patients underwent surgery and pathological examination. Twenty‐eight were diagnosed with thymic cysts and 14 with thymoma. The features of thymic cysts and thymomas revealed on MSCT were compared.

Results

Mediastinal masses with a triangular or teardrop shape and a straight mediastina–lung border were more likely to be diagnosed as thymic cysts (P < 0.05), while those with a bulging nodule–lung border were more likely thymomas (P < 0.05). Using the CT value as a reference for differential diagnosis, the diagnostic sensitivity, specificity, and area under the receiver operating characteristic curve for CT values of non‐contrast CT images, enhanced CT values, and ΔCT values were 0.65 (0.47–0.84), 0.95(0.86–1.00), and 0.96 (0.89–1.00), respectively.

Conclusion

MSCT of high‐density thymus gland nodules (maximum diameter ≤ 3 cm) can reveal specific features that could be helpful for differential diagnosis.

Imaging of pediatric neck masses

Palpable neck masses are a common indication for pediatric imaging. Such lesions may be caused by infectious, inflammatory, tumoral, traumatic, lymphovascular, immunologic, or congenital etiologies. Radiological assessment of neck masses in young children should be tailored based on patient presentation and physical examination, as well as clinical suspicion. The goal of imaging should be to help arrive at a diagnosis or limited differential in an efficient manner while minimizing radiation exposure.

Congenital cystic lesions of the head and neck

This article presents clinical characteristics and radiologic features of congenital cervical cystic masses, among them thyroglossal duct cysts, cystic hygromas, branchial cleft cysts, and the some of the rare congenital cysts, such as thymic and cervical bronchogenic cysts. The imaging options and the value of each for particular masses, as well as present clinical and radiologic images for each, are discussed.

Management of Congenital Third Branchial Arch Anomalies: A Systematic Review

OBJECTIVE: To systematically review the existing literature on third branchial arch anomalies and suggest guidelines for their management.

DATA SOURCES: We searched PubMed, Medline, and Embase using Scopus, and collected additional publications cited in bibliographies. We included all English-language articles and all foreign-language articles with an English abstract.

REVIEW METHODS: Two investigators reviewed all cases explicitly identified as third arch anomalies or meeting anatomical criteria for third arch anomalies; they assessed presentation, diagnostic methods, intervention, and outcome.

RESULTS: We found 202 cases of third arch anomalies; they presented primarily on the left side (89%), usually as neck abscess (39%) or acute suppurative thyroiditis (33%). Barium swallow, direct laryngoscopy, and magnetic resonance imaging were the most useful diagnostic tools. The recurrence rate varied among the treatment options: incision and drainage, 94 percent; endoscopic cauterization of the sinus tract opening, 18 percent; open-neck surgery and tract excision, 15 percent; and partial thyroidectomy during open-neck surgery, 14 percent. Complications after surgery appeared somewhat more frequently in children eight years of age or younger.

CONCLUSION: Third arch anomalies are more common than previously reported. They appear to be best treated by complete excision of the cyst, sinus, or fistula during a quiescent period. Repeated incision and drainage yields high rates of recurrence and should be avoided. Complications might be minimized by first initiating antibiotic treatment, delaying surgical treatment until the inflammatory process is maximally resolved, and by using endoscopic cauterization.

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.

Congenital cystic masses of the neck: radiologic-pathologic correlation

Cervical congenital cystic masses constitute an uncommon group of lesions usually diagnosed in infancy and childhood. The most common congenital neck mass is the thyroglossal duct cyst. The diagnosis is easily established from the presence of a cystic lesion in the anterior midline portion of the neck. The vast majority of branchial cleft cysts arise from the second branchial cleft. They can occur anywhere from the oropharyngeal tonsillar fossa to the supraclavicular region of the neck. Cystic hygroma is the most common form of lymphangioma. In the neck, cystic hygromas are most commonly found in the posterior cervical space. They typically extend into adjacent structures without respecting the fascial planes. Dermoid and epidermoid cysts result from sequestration of ectodermal tissue. The floor of the mouth is the most common location in the neck. Cervical thymic cysts are very uncommon lesions and are found anywhere from the angle of the mandible down to the sternum. Laryngoceles are classified into internal, external, and mixed types and have a frequent association with laryngeal carcinoma.

Congenital thymic cysts in children--mostly misdiagnosed

BACKGROUND/PURPOSE

Thymic cysts are rare lesions of the neck and mediastinum that are difficult to diagnose. Often considered inconsequential, these lesions can frequently be symptomatic. In this report the authors contrast their experience with that of the literature.

METHODS

From 1984 through 1997, the authors encountered 14 patients with this lesion. All cysts were completely excised. Patients that had an acquired cyst of the thymus were excluded from this series.

RESULTS

Of the 14 patients ranging in age from 2 weeks to 16 years, seven patients had cervical masses, five had mediastinal masses, and two children had both sites involved. Seven children were symptomatic with wheezing and upper respiratory infection, with cough and fever being the most common clinical features. Investigations included chest radiograph, contrast esophagram, sonography (US) and computerized tomography (CT). Displacement of vital mediastinal or neck structures was observed in eight patients. Only two patients received correct diagnosis before surgery. Successful and complete excision of all cysts was achieved. The cysts were benign and ranged in size from 2 to 22 cm in diameter.

CONCLUSION

Often forgotten, thymic cysts are rare benign lesions that should be considered in the differential diagnosis of cervical and mediastinal masses in children.

Aberrant cervical thymus: a case report and review of literature

This article illustrates a case of an aberrant cervical thymus presented as a neck mass. This is a case of a 4-month-old boy presenting with a right submandibular mass whose preoperative diagnosis was lymphangioma or neoplastic lesion. The mass was successfully removed and the histopathological examination showed normal thymic tissue with no diagnostic abnormality. This paper reviews the embryological background of aberrant cervical thymus, the varying clinical presentations with an emphasis on differential diagnosis, clinical work-up, and surgical treatment.

Non-nodal neck masses

Planar imaging has made significant contributions to the evaluation of patients with non-nodal neck masses. The clinical history, physical examination, and imaging characteristics of these lesions are often complimentary. Yet, planar imaging much more accurately defines the size, location, and extent of these lesions than is revealed on physical examination. The CT and MR characteristics are often sufficiently specific to arrive at the correct preoperative diagnosis in these patients. We present the classical radiographic and clinical features of several non-nodal neck masses.