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238 Neck: Cysts, Sinuses, and Fistulas
Differential Diagnosis 8. Strict haemostasis is maintained and the wound closed in layers. It
Midline dermoids, which occur commonly in the submental triangle, are is unnecessary to reapproximate the hyoid bone. Drainage is usually
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the commonest differential diagnosis. Ectopic midline thyroid, enlarged unnecessary unless haemostasis is unsatisfactory or there is previous
pyramidal lobe of thyroid gland, and thyroid adenomas may also present infection. A subcuticular stitch may be used to close the skin.
as midline masses. 9. Perioperative antibiotics are justified if previous infection of a cyst
Investigations has occurred or after operation on thyroglossal fistula.
Neck ultrasonography and thyroid iodine scintigraphy may be needed to Histologically, the tract usually contains pseudostratified ciliated
confirm the diagnosis and rule out ectopic thyroid tissue. columnar respiratory epithelium in 60% of cases and stratified
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Complications squamous epithelium in the rest. More than 100 carcinomas have
Thyroglossal fistula may result from infection of the thyroglossal cyst been reported from thyroglossal duct remnants. These are either
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or after drainage of a thyroglossal abscess. The fistula is usually in the papillary adenocarcinomas or squamous carcinomas. Most of these
midline. Sinograms are unnecessary for diagnosis, and sclerotherapy as malignancies arise in the substance of the ducts and not from metastasis
a means of treatment has not been described. from the thyroid glands. The tumours are slow-growing and confined to
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the neck for long periods. Most, including the affected lymph nodes.
Surgical Management can be managed surgically with the Sistrunk operation.
Both thyroglossal cysts and fistulas are surgically approached by the
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Sistrunk operation described by Walter Sistrunk in 1920. The aim of Other Rare Neck Masses
the operation is to completely excise the duct with the middle part of Many rare neck masses appear low in the neck and may have connec-
the body of the hyoid bone and a cuff of the tongue muscles because tions to masses in the thoracic cavity.
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side branches of the duct may occur within the muscles of the tongue. Bronchogenic Cysts
Complete excision of the duct is essential to prevent recurrence or Bronchogenic cysts are attached to the hilum of the lung and may
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malignant degeneration. present as low neck masses, where they may compress the trachea,
For the procedures outlined below, the patient is given general causing stridor.
anaesthesia with endotracheal intubation. In the supine position, a Lymphangiomas
sandbag is placed under the patient’s shoulders to extend the neck, and
Lymphagiomas involving the posterior mediastinum may extend to the
a head ring is used to steady the head. The neck, lower jaw, and upper
lower part of the neck, generally to the left of the trachea.
part of the chest are cleaned and draped.
Thymic Cysts and Mediastinal Tumours
Thyroglossal cyst
Thymic cysts and mediastinal tumours may rarely present with exten-
1. A transverse skin incision is made at the midpoint of the mass. The sions in the lower part of the neck.
incision is deepened through platysma and subcutaneous tissues to
reach the edge of the cyst. With strict haemostasis using diathermy, the Evidence-Based Research
tract is easily identified on the upper part of the cyst. Table 36.2 presents a retrospective study that reviews the types of congeni-
tal cysts, their management, and problems associated with management.
2. Thereafter the procedure follows as for a thyroglossal fistula.
Table 36.2: Evidence-based research.
Thyroglossal fistula
Title Congenital cysts and fistulas of the neck
1. An elliptical skin incision is made around the ostium. This skin
incision is deepened through platysma until the tract is identified. Authors Nicollas R, Guelfucci B, Roman S, Triglia JM
Institution Service d’ORL Pediatrique, Federation ORL Hospital de
2. Keeping very close to the tract, the tract is dissected between the la Timone, Marseille, France
sternohyoid muscles until the hyoid bone is identified.
Reference Intl J Pediatr Otorhinolaryng 2000; 55:117–124
3. The body of the hyoid bone is cleared from the sternohyoid
muscle inferiorly and the mylohyoid and geniohyoid muscles Design Retrospective study
superiorly with diathermy. Aim To review types of congenital cysts seen, the management
given, and problems associated with management.
4. An artery forceps is used to separate the body of the hyoid bone
from the thyrohyoid membrane inferiorly. Period 1984–1999.
Exclusion Preauricular cysts and cystic hygromas.
5. The middle portion of the hyoid bone is then excised either with a
strong straight scissors or with small bone cutters. Result Of 191 children with congenital cysts and fistulas, 123 were
malformations of the midline, 102 were thyroglossal duct
6. The hyoid bone is then held with towel clips and lifted to expose cysts, and 21 were dermoid cysts. Of the 68 malformations
the proximal part of the tract. This is now dissected to the floor of the of the laterocervical region, 37 were cysts and fistulas of
second cleft, 20 were cysts of first cleft, 7 were cysts of
mouth. The anaesthetist may be asked to depress the tongue with a
fourth pouch, and 4 were thymic cysts.
gloved finger to assist the surgeon to locate the foramen caecum but
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this manouvre is usually not necessary. Problems in Diagnosis and management of midline masses are usually
management straightforward. Misdiagnosis of lateral cysts is common and
7. At the foramen caecum, a small rectangular piece of hyoglossus and often leads to inadequate treatment and recurrence.
genioglossus are excised with the tract.