Branchial cleft cysts are congenital epithelial cysts that arise on the lateral part of the neck from a failure of obliteration of the second branchial cleft in embryonic development.[1]
Phylogenetically, the branchial apparatus is related to gill slits. In fish and amphibians, these structures are responsible for the development of the gills—hence the term branchial (from Greek branchia ["gills"]).
Surgical excision is definitive treatment for branchial cleft cysts. Antibiotics are required to treat any related infections or abscesses. Patients should be reassured that branchial cleft cysts are benign.
At the fourth week of embryonic life, the development of four branchial (or pharyngeal) clefts results in five ridges known as the branchial (or pharyngeal) arches, which contribute to the formation of various structures of the head, the neck, and the thorax. The second arch grows caudally and, ultimately, covers the third and fourth arches. The buried clefts become ectoderm-lined cavities, which normally involute around week 7 of development. If a portion of a cleft fails to involute completely, the entrapped remnant forms an epithelium-lined cyst with or without a sinus tract to the overlying skin.[1]
These lesions may be clinically divided into four main types (first, second, third, and fourth branchial cleft cysts) according to their location and the arch involved in their pathogenesis. The majority of branchial cleft cysts arise from the second branchial cleft.[1]
Although most of these cysts are benign, rare cases of malignant transformation have been reported.[2]
The exact incidence of branchial cleft cysts in the US population is unknown. In the pediatric population, branchial cleft cysts are the second most common congenital cause of a neck mass.[1] An estimated 2-3% of cases are bilateral. A tendency exists for cases to cluster in families.
Although branchial cleft cysts are congenital in nature, they may not present clinically until later in life, usually by early adulthood. No sexual predilection is recognized for branchial cleft cysts, nor has any racial predilection been reported.
Many branchial cleft cysts are asymptomatic. They may become tender, enlarged, or inflamed, or they may develop abscesses, especially during periods of upper respiratory tract infection, as a consequence of the lymphoid tissue located beneath the epithelium. Spontaneous rupture of an abscessed branchial cleft cyst may result in a purulent draining sinus to the skin or the pharynx.
Depending on the size and the anatomic extension of the mass, local symptoms, such as dysphagia, dysphonia, dyspnea, and stridor, may occur.
After surgical excision of branchial cleft cysts, the recurrence rate has typically been low, at an estimated 3%, unless surgical treatment has previously been performed or recurrent infection has developed, in which case rates as high as 20% have been reported.
In a study using data from the American College of Surgeons (ACS) National Surgical Quality Improvement Program adult (NSQIP) and pediatric (NSQIP-P) databases, Moroco et al assessed outcomes of surgical excision of branchial cleft cysts in children (n = 1775) and adults (n = 677).[3] The postoperative complication rate was low in both groups: 3.9% in children and less than 1% in adults. In adults, smoking status had a significant effect on the complication rate. The readmission rate was also low in both groups: 1.1% in children and 1.2% in adults.
In another study that used NSQIP-P data, Raghavan et al reported a postoperative complication rate of 3% in pediatric patients who underwent excision of a branchial cleft cyst.[4]
A branchial cyst commonly presents as a solitary, painless mass in the neck of a child or a young adult. A history of intermittent swelling and tenderness of the lesion during upper respiratory tract infection may exist. Discharge may be reported if the lesion is associated with a sinus tract.
In some instances, branchial cleft cyst patients may present with locally compressive symptoms. A family history of branchial cleft cysts may be present.
A primary branchial cleft cyst lesion is a smooth, nontender, fluctuant mass that occurs along the lower one third of the anteromedial border of the sternocleidomastoid muscle between the muscle and the overlying skin. A secondary branchial cleft cyst lesion may be tender if secondarily inflamed or infected. When associated with a sinus tract, mucoid or purulent discharge onto the skin or into the pharynx may be present.
Rarely, branchial cleft cysts have been reported as fluctuant nodules on the thorax[5] and even in the posterior mediastinum.[6]
No specific laboratory investigations are required in the workup of a branchial cleft cyst. No other investigations are needed beyond routine preoperative workup.
A sinogram may be obtained. If a sinus tract exists, radiopaque dye can be injected to delineate the course of the tract and determine the size of the cyst.
Ultrasonography (US) helps identify the cystic nature of these lesions.[8, 9] A retrospective study (N = 17) examining the accuracy of US in the diagnosis of branchial cleft cysts reported a sensitivity of 82.4% and a specificity of 66.7% for US diagnosis.[10]
Contrast-enhanced computed tomography (CT) will show a cystic and enhancing mass in the neck (see the images below). It may aid preoperative planning and identify compromise of local structures.
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First branchial cleft cyst, type II. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals an ill-defined, nonenhanc....
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Second branchial cleft cyst. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals a large, well-defined, nonenhanci....
Magnetic resonance imaging (MRI) yields finer resolution during preoperative planning. The wall may be enhancing on gadolinium scans.[8]
Fine-needle aspiration (FNA) may be helpful for distinguishing branchial cleft cysts from malignant neck masses.[11] This is generally a safe procedure, but complications (eg, infection) can occur on occasion.[12]
FNA and culture may help guide antibiotic therapy for infected cysts.
Most branchial cleft cysts are lined with stratified squamous epithelium with keratinous debris within the cyst. In a small number, the cyst is lined with respiratory (ciliated columnar) epithelium. Lymphoid tissue is often present outside the epithelial lining. Germinal center formation may be seen in the lymphoid component, but true lymph node architecture is not seen. In infected or ruptured lesions, inflammatory cells are seen within the cyst cavity or the surrounding stroma.
Surgical excision is definitive treatment for branchial cleft cysts. A series of horizontal incisions, known as a stairstep or stepladder incision, is made to fully dissect out the occasionally tortuous path of the branchial cleft cysts. Branchial cleft cyst surgery is best delayed until the patient is at least 3 months of age. Definitive branchial cleft cyst surgery should not be attempted during an episode of acute infection or if an abscess is present. An abscess should be treated by means of surgical incision and drainage, usually along with concurrent antimicrobial therapy.
The main disadvantage of the traditional surgical approach is a relatively significant degree of scarring. Accordingly, alternatives to the open surgical method have been proposed, including a retroauricular approach, a facelift approach, and endoscopic-assisted removal. All of these newer surgical methods may be limited with regard to their ability to achieve full visualization of the lesion.
A case-controlled study suggested that an endoscopic retroauricular approach may provide good surgical clearing with minimal scarring for second branchial cleft cysts.[13, 14] A systematic review (four studies; 140 operated cysts) of different surgical approaches to second branchial cleft cysts found that patients treated with an endoscopic or retroauricular approach had a higher rate of temporary complications but significantly greater scar satisfaction at 3-6 months.[15]
Sclerotherapy with OK-432 (picibanil) has been reported to be an effective alternative to surgical excision of branchial cleft cysts by some groups,[16] including some using ultrasonographic (US) guidance.[17] Other agents that have been employed in sclerotherapy for benign cystic head and neck lesions include ethanol, doxycycline, tetracycline, and bleomycin.[18]
A study assessing the clinical and aesthetic outcomes of percutaneous injection of sclerosant agents for head and neck cystic malformations found that this approach provided only limited clinical benefit for branchial cleft cysts as compared with other malformations.[19]
Untreated branchial cleft cyst lesions are prone to recurrent infection and abscess formation with resultant scar formation and possible compromise to local structures.
Complications of surgical excision of branchial cleft cysts result from damage to nearby vascular or neural structures, which include carotid vessels and the facial, hypoglossal, vagus, and lingual nerves.
There are rare case reports of malignancies having been identified in branchial cleft lesions, including branchiogenic carcinoma and papillary thyroid carcinoma.
Postoperatively, patients should be monitored for branchial cleft cyst recurrence. Because some patients have bilateral branchial cleft cyst lesions, the contralateral side should be examined.
What is a branchial cleft cyst?What is the pathophysiology of branchial cleft cyst?What causes branchial cleft cyst?What is the prevalence of branchial cleft cyst in the US and which patient groups are at highest risk?What is the prognosis of branchial cleft cyst?What should patients be told about branchial cleft cyst?What are the signs and symptoms of a branchial cleft cyst?Which physical findings are characteristic of a branchial cleft cyst?Which conditions should be included in the differential diagnosis of branchial cleft cyst?What is the role of lab studies in the workup of branchial cleft cyst?What is the role of imaging studies in the workup of branchial cleft cyst?Besides imaging studies, what other tests are performed in the workup of branchial cleft cyst?What is the role of fine-needle aspiration in the workup of branchial cleft cyst?Which histologic findings are characteristic of branchial cleft cyst?What is the role of antibiotics for the treatment of branchial cleft cyst?What is the role of surgery in the treatment of branchial cleft cyst?What are the complications of branchial cleft cyst?Which specialist consultations are required for the treatment of branchial cleft cyst?What is included in long-term monitoring of patients with branchial cleft cyst?
Chih-Ho Hong, MD, FRCPC, Clinical Associate Professor, Department of Dermatology and Skin Science, University of British Columbia, Canada
Disclosure: Nothing to disclose.
Coauthor(s)
Richard Crawford, MD, FRCPC, Head of Dermatology, Clinical Professor, Department of Medicine, Divisions of Pathology and Dermatology, University of British Columbia Faculty of Medicine, Canada
Disclosure: Nothing to disclose.
Specialty Editors
Michael J Wells, MD, FAAD, Dermatologic/Mohs Surgeon, The Surgery Center at Plano Dermatology
Disclosure: Nothing to disclose.
Edward F Chan, MD, Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania School of Medicine
Disclosure: Nothing to disclose.
Chief Editor
William D James, MD, Emeritus Professor, Department of Dermatology, University of Pennsylvania School of Medicine
Disclosure: Received income in an amount equal to or greater than $250 from: Elsevier<br/>Served as a speaker for various universities, dermatology societies, and dermatology departments.
Additional Contributors
Jean Paul Ortonne, MD, Chair, Department of Dermatology, Professor, Hospital L'Archet, Nice University, France
First branchial cleft cyst, type II. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals an ill-defined, nonenhancing, water attenuation mass (m) posterior to the right submandibular gland (g).
Second branchial cleft cyst. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals a large, well-defined, nonenhancing, water attenuation mass (m) on the anterior border of the left sternocleidomastoid muscle(s).
First branchial cleft cyst, type II. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals an ill-defined, nonenhancing, water attenuation mass (m) posterior to the right submandibular gland (g).
Second branchial cleft cyst. Contrast-enhanced axial computed tomography scan at the level of the hyoid bone reveals a large, well-defined, nonenhancing, water attenuation mass (m) on the anterior border of the left sternocleidomastoid muscle(s).
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