Congenital Neck Masses

Thyroglossal Duct Cyst

A thyroglossal duct cyst is a fibrous cyst that forms from a persistent thyroglossal duct. The thyroglossal duct is an embryological midline structure that joints the point of formation of the thyroid gland (foramen cecum at the posterior tongue) to the anatomical position of the thyroid duct. Normally, the thyroglossal duct atrophies. If it persists, oral secretions and mucus accumulate in the duct to eventually form a cyst.

65-70% of thyroglossal duct cysts are below the hyoid bone, 20% are above, and the rest are at the hyoid bone.

• Patient History
  • Less than 20 years old (majority are school-age children)
• Signs and symptoms
  • Midline neck mass
    • Region of the hyoid bone
    • Painless
    • Smooth
    • Cystic in appearance
    • Approximately 1-2 cm in diameter
    • Moves upwards with protrusion of the tongue
  • Dysphagia and Stridor if the cyst is large enough
• Physical exam
  • Midline mass that moves with tongue protrussion
• Differential diagnosis
  • Goiter: get thyroid function tests
• Investigations
  • Ultrasound: best initial test
    • Hypoechoic in relation to surrounding tissue
  • CT scan: if the patient is an adult. To rule out malignancy
  • Thyroid function test: to rule out goiter
• Treatment
  • Surgical excision: Sistrunk procedure
    • Involves removing the cyst, sinuses, fistulas, and the middle third of the tongue
    • Surgery is contraindicated during acute infection

Branchial Cleft Cyst

Branchial cleft cysts are an epithelial lined cysts developing from failure of the 2nd and 3rd branchial archest to fuse. All branchial cleft anomalies are found along the sternocleidomastoid and anterior triangle. Branchial cleft cysts are commonly found in the preauricular part of the anterior triangle (superior part)

• Signs and symptoms
  • Lateral neck mass
    • May grow and shrink with the coming and going of various infections e.g. URTI
  • Rarely large enough to cause dysphagia and stridor
• Investigations
  • Ultrasound
  • CT scan with contrast: in adults or if ultrasound is non-diagnostic. Also useful pre-op.
• Treatment
  • Surgical excision

Cystic Hygroma

A cystic hygroma is a congenital deformity of the lymphatic vessels in the neck causing a multiloculated benign lesion that varies in size. It occurs in the posterior triangle but can extend into the anterior triangle and even cross the midline. Its size can vary depending on the amount of lymph drained. They are usually diagnosed antenatally. There is also an association with Turner’s syndrome. If a cystic hygroma is presumed antenatally from ultrasound the neonate can be delivered in a facility with a NICU by an obstetrician via C-section, then referred to a pediatric surgeon.

• Patient History
  • Turner syndrome
    • School-aged girl with short stature, low-set ears, learning difficulty, webbed neck
    • Not yet menstruated or developed secondary sex characteristics
    • Lymphedema of hands and feet
    • Coarctation of aorta
• Signs and symptoms
  • Neck mass
    • Transilluminates
    • Increases in size during infection (lymphatic drainage increases)
    • Sudden increases in size can pose the risk of hemorrhage
  • Facial and neck distortion
  • Difficulty feeding
  • Respiratory distress
  • Compression of the brachial plexus
    • Upper extremity pain
    • Weakness
• Investigation
  • MRI with contrast: best initial diagnostic test. Provides better soft-tissue detail than CT. Contrast to differentiate between hemangioma
• Treatment
  • Partial surgical resection. Rarely removes all of the hygroma
  • Sclerosing agents

Thymic Cyst

A thymic cyst is a remnant of the thymus in the neck. Unlike thymomas, thymic cysts are not associated with myasthenia gravis. They are associated with both malignant and benign hyperplasia.

95% are unilateral.

• Signs and symptoms
  • Neck mass in the anterior triangle
  • Dysphagia if large enough
• Investigations
  • CT: to rule out other possibilities including thymoma
  • Biopsy: to rule out malignant transformation
• Treatment
  • Surgical excision

Parathyroid Cyst

Parathyroid cysts are rare. They occur in a paratracheal position just inferior to the thyroid.

• Patient History
  • 30-50 year old concerned about a ‘thyroid nodule’
• Signs and symptoms
  • Hoarseness, respiratory obstruction, and tracheal deviation
  • Signs associated with hypercalcemia in “functioning cysts”
• Treatment
  • Surgical excision

Benign neck masses

Primarily found in children

Hemangioma of the neck

This is a tumour involving blood vessel epithelial cells, resulting in an abnormal collection of vessels. It is the most common tumor of the head and neck in pediatric patients. Symptoms depend on the specific type of hemangioma. Cutaneous hemangiomas are grossly visible, while invasive hemangiomas are palpable and non-compressible masses. Treatment is on a case-by-case basis.

• Types
  • Capillary hemangioma: most common in pediatrics. Has cutaneous lesions (nevus flammeus, strawberry nevus), and extracutaneous lesions (typically in the liver). Early proliferation and spontaneous regression. Unless grotesquely large, capillary hemangiomas are left to be. If they don’t regress by age 5, treat with steroids (prednisolone) or surgical removal (laser incision). Nevus flammeus, which is a two-dimensional “birthmark”. Source Strawberry nevus, which is a palpable mass. Source
  • Cavernous hemangioma: more common in adults, occurs in deeper tissues (CNS, liver, eyes)
  • Arteriovenous hemangioma: occurs in various places, and especially associated with congenital syndromes eg. Sturge-Weber syndrome
  • Invasive hemangioma: extends deeper into subcutaneous tissue, fascia, and muscles, often painful
  • Subglottic hematoma: capillary hemangioma presenting at birth, associated with stridor and airway obstruction. They require airway stabilization, steroids, and laser excision.
• Diagnosis
  • Capillary hemangiomas
    • CT head and neck with contrast
  • Cavernous hemangiomas
    • CT head and neck with contrast
  • Invasive hemangiomas
    • Suspected based on physical exam, doppler sonogram, CT
    • Most accurate test: angiogram
  • Subglottic hemangiomas
    • Direct visualisation of the airway

Teratoma of the neck

Teratomas are neoplastic growths of multiple tissue types foreign to the part of the body in which they arise due to post-meiotic cells. May be benign or malignant. Pediatric cases are almost always benign. Cervical teratomas are usually present at birth or shortly thereafter. The average size at presentation is 5-12cm and they are typically unilateral. Best initial diagnostic test is CT, followed by FNA. Treatment is by surgical incision.

• Symptoms
  • Due to tracheal compression
    • Stridor
    • Cyanosis
    • Tracheal deviation
    • Palpable neck mass
    • Neck swelling

Laryngeal papilloma

Most common laryngeal tumour. It may occur at any age.

• Cause
  • HPV 6 or 11; which may be transmitted during vaginal delivery from an infected mother
• Symptoms
  • Usually a slow progression (over 6 months) from hoarseness to stridor to obstruction
• Diagnosis
  • Most accurate test: biopsy
  • Bronchoscopy
• Treatment
  • Surgical excision by either laser vaporisation or cold knife resection
  • Cidofovir: used for recurrent cases