What is the diagnosis and treatment for a first branchial cleft cyst?

From the Guidelines

A first branchial cleft cyst should be treated with complete surgical excision to prevent recurrent infections and potential complications, as recommended by the most recent clinical practice guidelines 1. When managing a first branchial cleft cyst, it is crucial to consider the potential for malignancy, especially in adult patients, as the incidence of cancer in a cystic neck mass increases to 80% in patients over 40 years old 1.

Key Considerations

• The diagnosis of a first branchial cleft cyst is typically made through physical examination, imaging studies like ultrasound, CT, or MRI, and sometimes fine-needle aspiration (FNA) 1.
• FNA should be used as the first-line modality for histologic assessment for any adult with a cystic neck mass, but its sensitivity is lower in cystic cervical metastases (73%) versus solid masses (90%) 1.
• If malignancy is suspected in the neck mass and repeated FNA or image-guided FNA are inadequate or benign, an expedient open excisional biopsy is recommended to establish a definitive diagnosis 1.
• Complete surgical removal is essential as incomplete excision can lead to recurrence, and the surgery requires careful dissection as these cysts often have close relationships with facial nerve branches 1.

Treatment Approach

• Surgery should be performed when the cyst is not actively infected; if infection is present, antibiotics should be administered first to resolve the infection before surgical intervention.
• The procedure is best performed by an experienced head and neck surgeon or otolaryngologist due to the technically challenging nature of the surgery.
• Imaging characteristics suggestive of malignant processes, such as large size, central necrosis with rim enhancement after contrast, multiple enlarged lymph nodes, extracapsular spread, asymmetric thickness of the wall, areas of nodularity, and nonconforming nature of the cystic wall, should be assessed when a cystic neck mass is observed 1.

From the Research

Definition and Characteristics

• First brachial cleft cysts are congenital epithelial cysts that arise from the lateral part of the neck, specifically from the first branchial cleft 2.
• They may present as a cyst, sinus, or fistula, and are usually recognized in patients before the age of 5, but can also appear in adults between 20 and 40 years old 3.
• These cysts are typically smooth and resilient, and can be found in the lateral region of the neck 3.

Diagnosis and Evaluation

• Ultrasonography, computerized tomography, and magnetic resonance imaging can be used to evaluate and differentiate these lesions, as well as to reveal the presence of fistulae 3, 4.
• Fine needle aspiration cytology (FNAC) is also a useful diagnostic tool for branchial cleft cysts 4.
• Electrophysiological facial nerve localization can be used to assess the safety and efficacy of surgical excision of first branchial cleft cysts 5.

Treatment and Management

• The only effective treatment for first brachial cleft cysts is total surgical excision 3, 4, 5.
• Minimally invasive surgery under local anesthesia can be used in adequately selected cases 6.
• Complete excision is necessary to avoid recurrence and complications, such as infection and facial nerve injury 3, 4, 5.
• The surgical approach must ensure safe and complete cyst removal to avoid intraoperative complications and recurrences 4.

Types of First Brachial Cleft Cysts

• Type I anomalies are purely ectodermal and extremely rare, while type II anomalies exhibit both ectodermal and mesodermal elements 2.
• Type I lesions are typically found posterior to the pinna and concha, and are usually superior to the main trunk of the facial nerve 2.
• Type II lesions are more numerous and can be associated with the parotid gland, as well as fistulae in the concha or external auditory canal 2.