Branchial Cleft CystBranchial Cleft Cyst

What is a Branchial Cyst?What is a Branchial Cyst?

Definition:Definition:

Congenital Congenital epithelial cystsepithelial cysts, which arise , which arise on the on the lateral part of the necklateral part of the neck due to due to failure of obliteration of the failure of obliteration of the second second branchialbranchial cleft in embryonic development. cleft in embryonic development.

Branchila cleft cyst = Lymphoepithelial Branchila cleft cyst = Lymphoepithelial cyst “Lymphatic origin, Modern Theory”cyst “Lymphatic origin, Modern Theory”

The name branchial means in Greek The name branchial means in Greek “Gill” , Those structures are responsible of “Gill” , Those structures are responsible of development of Gills in fish. “Classic development of Gills in fish. “Classic Theory”Theory”

Commonest cysts to arise in the neck. Commonest cysts to arise in the neck.

Classical locationClassical location

Anterior to the Anterior to the sternocleidomastoid sternocleidomastoid muscle. muscle.

However there have However there have been a number of been a number of case reports case reports describing cysts describing cysts which were found in which were found in areas other than the areas other than the classical position. classical position.

EtiologyEtiology

Many theoriesMany theories They can be grouped into two categories: They can be grouped into two categories:

the congenital the congenital The cervical lymph nodes cystic The cervical lymph nodes cystic

transformation theories. transformation theories.

Easier approach to EmbryologyEasier approach to Embryology

Structures between the developing head Structures between the developing head and the heart (i.e., the face, neck, and the heart (i.e., the face, neck, oropharynx, and the larynx) develop from oropharynx, and the larynx) develop from the branchial apparatus. the branchial apparatus.

There are six branchial arches; the last There are six branchial arches; the last two are rudimentary.two are rudimentary.

Each arch has a bar of mesoderm.Each arch has a bar of mesoderm.

Caudal to each of the four arches is an internal Caudal to each of the four arches is an internal

pouch lined with entoderm. pouch lined with entoderm.

Externally is branchial cleft, lined with ectoderm. Externally is branchial cleft, lined with ectoderm.

Between each bar, a branchial plate, composed Between each bar, a branchial plate, composed

of entoderm and ectoderm, separates the of entoderm and ectoderm, separates the

branchial cleft from the branchial pouch. branchial cleft from the branchial pouch.

Anatomical ConsiderationsAnatomical Considerations The second arch grows The second arch grows

downwards and ultimately downwards and ultimately covers the third and covers the third and fourth arches. fourth arches.

The buried clefts normally The buried clefts normally disappear around the disappear around the seventh week of seventh week of development. development.

If a portion of the cleft If a portion of the cleft remains entrapped and remains entrapped and fails to disappear, its fails to disappear, its remnants form a cyst.  remnants form a cyst. 

Second cleft Cyst with tract Second cleft Cyst with tract extending up to Pharynx extending up to Pharynx

Note tract goes Note tract goes between internal & between internal & external carotid external carotid arteries and close to arteries and close to cranial nerves IX, X, cranial nerves IX, X, XII which control XII which control among other functions among other functions tongue movement and tongue movement and swallowing.swallowing.

Clinical PresentationClinical Presentation

History History

Solitary, painless mass in the neck of a child Solitary, painless mass in the neck of a child or a young adult. or a young adult.

History of intermittent swelling and History of intermittent swelling and tenderness of the lesion during upper tenderness of the lesion during upper respiratory tract infection may exist.respiratory tract infection may exist.

Discharge if associated with a sinus tract. Discharge if associated with a sinus tract. May present with locally compressive May present with locally compressive

symptoms. symptoms. ++ family history. family history.

Physical ExaminationPhysical Examination

Primary lesion: Branchial cysts are smooth, Primary lesion: Branchial cysts are smooth, nontender, fluctuant masses, which occur nontender, fluctuant masses, which occur along the lower one third of the anteromedial along the lower one third of the anteromedial border of the sternocleidomastoid muscle border of the sternocleidomastoid muscle between the muscle and the overlying skin. between the muscle and the overlying skin.

Secondary lesion: The lesion may be tender Secondary lesion: The lesion may be tender if secondarily inflamed or infected. When if secondarily inflamed or infected. When associated with a sinus tract, mucoid or associated with a sinus tract, mucoid or purulent discharge onto the skin or into the purulent discharge onto the skin or into the pharynx may be present.pharynx may be present.

DiagnosisDiagnosis Cyst arising off midline of the neck and having Cyst arising off midline of the neck and having

lymphoepithelial characteristics should be lymphoepithelial characteristics should be regarded as a branchial cyst. regarded as a branchial cyst.

Usually occur in the 2nd or 3rd decade of life. Usually occur in the 2nd or 3rd decade of life. Most commonly found in the anterior triangle of Most commonly found in the anterior triangle of

the neck anterior to the upper third of the the neck anterior to the upper third of the sternomastoid. sternomastoid.

A cyst occupying the posterior triangle is A cyst occupying the posterior triangle is extremely rare. extremely rare.

Hence they should be suspected in all the cystic Hence they should be suspected in all the cystic swellings of the neck except the median ones. swellings of the neck except the median ones.

ImagingImaging

On general principle it’s less helpful than On general principle it’s less helpful than expectedexpected

Although you can always tell where is the Although you can always tell where is the lesion, but differentiating between other lesion, but differentiating between other causes of cystic neck masses is not causes of cystic neck masses is not always easy.always easy.

UltrasoundUltrasound Well defined, echogenic mass usually Well defined, echogenic mass usually

anterior to the carotid artery, draped anterior to the carotid artery, draped anterior to the sternocleidomastoid muscle anterior to the sternocleidomastoid muscle

CTCT

Well defined, low density unilocular mass Well defined, low density unilocular mass with a thin uniformly enhancing rim with a thin uniformly enhancing rim

Axial contrast-enhanced CT scan shows a left-sided cyst with a thick, enhancing

rim. This cyst is behind the submandibular gland, lateral to the carotid sheath

structures, and deep to the anterior margin of the sternocleidomastoid muscle.

There is an enhancing tract (arrow) extending from the cyst toward the left palatine

tonsil. This was an infected second branchial cleft cyst with an internal tract. Such

a tract typically passes between the internal and external carotid arteries and ends

in the palatine tonsil.

MRIMRI

MRI allows for finer resolution during MRI allows for finer resolution during preoperative planning. The wall may be preoperative planning. The wall may be enhancing on gadolinium scans.enhancing on gadolinium scans.

Differential Diagnosis Differential Diagnosis Branchiogenic carcinomaBranchiogenic carcinoma Tuberculous adenitisTuberculous adenitis LipomaLipoma Metastatic malignant neoplasms (SCCA from a primary site in the Metastatic malignant neoplasms (SCCA from a primary site in the

aerodigestive tract)aerodigestive tract) Cystic hygroma (lymphangioma)Cystic hygroma (lymphangioma) Carotid body tumorsCarotid body tumors LymphomasLymphomas HemangiomasHemangiomas Thyroid cystsThyroid cysts Ectopic thyroidEctopic thyroid Cervical thymic cystsCervical thymic cysts Thyroglossal duct cystThyroglossal duct cyst Parotid cystic tumorsParotid cystic tumors

Axial contrast-enhanced CT scan shows a well-delineated fatty mass in the subcutaneous tissues of the back of the neck.

Branchial cleft cyst

Branchial cleft cystCystic hygroma Cystic lymphangioma

Parotid, malignant tumors. Axial T1-

weighted MRI with fat saturation and

contrast enhancement shows an

enhancing mass extending into the

superficial and deep lobes of the right

parotid gland. Pathology indicated a

squamous cell carcinoma.

Branchial cleft cyst

T1-Weighted MRI. A well defined mass is present along theanterior triangle of the neck on the right side. There are low signal regionswithin this mass suggesting the presence of calcifications and flow-voids (arrows).

T2-Weighted Axial Images Through the Submandi-bular Region. The mass is bright on T2-weighted images and again exhibits focal lucencies

compatible with flow voids.

Contrast Enhanced MR in the Axial Plane.There is bright enhancement of the mass. Flow voidsproduce a "salt and pepper" appearance.

Paragangliomas

Axial contrast-enhanced CT scan shows a well-delineated irregular mass lesion taking early KM enhancment

Hemangioma

Branchial cleft cyst

TreatmentTreatment

The treatment of branchial cleft cysts is The treatment of branchial cleft cysts is surgical excision.surgical excision.

This branchial cleft cyst was followed superiorly to the This branchial cleft cyst was followed superiorly to the region of the oropharynx, but no communication was region of the oropharynx, but no communication was

found.  The picture below shows the anatomy of the carotid found.  The picture below shows the anatomy of the carotid triangle after removal of the cyst. triangle after removal of the cyst.

Thank YouThank You

Marina Waves, Salmiya Waterfront, KuwaitMarina Waves, Salmiya Waterfront, Kuwait