Cysts of the neck
Midline cyst
Lateral cyst
1. submental dermoid cyst.
1. cystic hygroma.
2. thyroglossal cyst.
2. plunging ranula.
3. subhyoid bursitis.
3. branchial cyst.
4. cyst in the thyroid isthmus.
4. cyst in thyroid lobe.
5. cold abscess in submental or
5. cold abscess.
prelaryngeal L.N.
6. Laryngeocele.
6. pharyngeal pouch.
7. pneumatocele.
7. Suprasternal dermoid.
I. dermoid cyst:
Definition : cyst which is due to continued epithelial growth under the
skin.
Types:
1- Sequestration dermoid cyst:
occurs during development where some epithelial cells become
sequestrated beneath the lines of fusion between the dermatomes. The
cyst will be formed later in life.
2- Tubulodermoid:
due to distension of embryonic duct remanent as:

thyroglossal cyst (from thyroglossal duct)

branchial cyst (from cervical sinus)

post anal dermoid cyst.
3- Implantation dermoid cyst:
occurs commonly in the fingers, palm, sole and in relation to skin wound.
They are due to puncture wounds (pin prick) in which some of the
epithelial cells are implanted into the subcutaneous tissue which will
grow forming a cyst.
4- Teratomatous dermoid cyst:
It is a benign form of teratoma. Usually occurs in the testis and ovary. It
is due to inclusion of embryonic toti potent cells in the ovary during
development. The wall is made of skin containing teeth, hair, bone and
cartilage.
Sequestration dermoid cyst:

Although it is congenital yet it may not appear except late.

It occurs at the line of fusion.
o Neck and trunk: midline anteriorly and posteriorly.
o Face:
junction
between
frontonasal-maxillary
and
mandibular process.
o Limbs: no line of fusion as the limbs develop as bud.

Pathology: the cyst is small lined by squamous epithelium contains
sebaceous material and covered by fibrous tissue.

Complications:
o Infection leading to abscess.
o Rarely external angular dermoid in the face may have an
intracranial extension.
o Malignant change is very rare.

Types of sequestration dermoid cysts:
a- External angular dermoid: occurs at the lateral side of the orbital
margin at the line of fusion of the frontonasal and maxillary
process.
b- sublingual dermoid cyst: (submental) in the midline of the neck
either:
1- Inframyelohyoid cyst: below the myelohyoid muscle. Does not
move with protrusion of the tongue nor with deglutition.
2- supramyelohoid cyst: bulges in the floor of the mouth above the
myelohoid muscle.
c- Suprasternal dermoid cyst: in the midline at the suprasternal notch.

Clinical picture of dermoid cyst: well defined cystic swelling with
smooth surface. Rounded or oval in shape, not tender unless inflamed,
mobile over the deep structures. The skin overlying could be separated
from the swelling. The cyst in not compressible nor translucent.

Treatment:
o Excision.
o If infected it is only incised and drained.
o If it has an intracranial extension it is left until adulthood
when the bones close and the stalk between the two partws
of the cyst is obliterated then the subcutaneous part is
excised.
II. Thyroglossal cyst:
It is the commenest midline neck cyst.
The thyroglossal tract arises from the foramen caecum in the tongue at
the junction between the anterior 2/3 and posterior 1/3 then descends
downwards either infront or inside the hyoid bone then passes slightly
upwards behind the hyoid bone then descends downwards again to form
the thyroid isthmus and the medial portion of the thyroid lobes. The duct
atrophies at the 6th week if it does not atrophy it persists as a thyroglossal
duct forming the thyroglossal cyst..

Pathology:
Males and females are equally effected. The age range from 4 months to
70 years. 90% are in the midline. 10% are to one side of these 95% on the
left side and 5% on the right side.
The site incidence:
Prehyoid 75%.
Thyroid cartilage 15%.
Suprahyoid 5%
Cricoid 4%
Base of the tongue 1%.

Clinical picture:
Painless swelling moving with protrusion of the tongue. The cyst is
mobile and if low in the neck the subcutaneous tract could be felt. Cyst at
the base of the tongue may cause dysarthria and should be differentiated
from lingual thyroid by thyroid scan.

Complications:
Infection leading to abscess.
Fistula: thyroglossal fistula is never congenital it is due to either
abscess in a thyroglossal cyst or incomplete removal.

Treatment:
Sistrunk operation where we remove the cyst, all the tract, the central part
of the hyoid bone and part of the base of the tongue.
III. Branchial cyst:
External auditory meatus
2nd
3rd
4th
Normally
disappear
Four grooves, branchial cleft and the intervening bars are the branchial arches.
It arises from vestigial remnant of the 2nd branchial cleft. The cyst
contains mucoid fluid with many cholesterol crystals. The wall is lined
with epithelial tissue and contains lymphoid tissue.

Clinical picture
Usually at the age of 20 years as a slowly growing painless swelling at
the upper lateral part of the neck between upper and middle third which is
partially undercover the anterior border of the sternomastoid. It
transilluminates.

Complications: infection which is treated by antibiotics - branchial
fistula - branchiogenic carcinoma.

Treatment by complete excision reaching the deep structures near the
external auditory meatus.
N.B.: the branchial fistula may be congenital due to persistence of 2 nd
branchial cleft. It occurs at the lower 1/3 of the anterior border of the
sternomastoid. The inner opening is just behind the tunsil or may be blind
(sinus). It may also be acquired due to infection or incomplete removal of
a branchial cyst. It discharge mucoid or mucopurulent material. It is
treated by complete excision via transverse neck incision.
IV. Subhyoid bursitis:
Inflammation of the subhyoid bursa giving a cystic transverse swelling
below the hyoid bone moving with deglutition.
V. Laryngeocele:
Occurs in wind instruments players due to herniation of the laryngeal
mucous membrane through the thyrohyoid membrane. It forms a tense
cystic resonant translucent swelling which is compressible and enlarge
when the patient blow and close the nose.
VI. Pneumatocele:
Herniation of the lung apex through the sibson fascia (suprapleural
membrane) which is attached between the transverse process of the 7 th
cervical vertebrae and the inner border of the 1st rib. It gives a
compressible resonant swelling at eh supraclavicular region specially on
straining.
VII. Cystic hygroma:
Due to congenital lymphatic anomaly. Where the lymphatic spaces have
afferent without efferent vessels.
It appears at birth commonly at the lower part of the neck in the posterior
triangle but it may arise in the groin, mediastinum or axilla.
It is brilliantly transleuscent cystic swelling which is partially
compressible.
Complications: infection, respiratory obstruction, obstructed labour.
Treatment: better at 2 years by excision but if causing respiratory
obstruction aspiration is done if failed tracheostomy.
VIII. Plunging ranula:
It is a buccal ranula which has a deep extension in the neck and appears
below the mandible.
A ranula is a retention cyst that arises from the glands in the floor of the
mouth (glands of Balandin and Nuhn). It also may be due to extravasation
from the sublingual gland.