By Alexis Furze, M.D.

THE PEDIATRIC NECK MASS

The Pharyngeal or Branchial arches first appear in the 4th week of gestation in the region of the fetal head and neck.  Each arch is separated by a cleft (ectoderm) externally and a pouch (endoderm) internally.  Clefts and pouches resemble the formation of gills in fish and amphibia but never connect to form true gills in the human.  The tissue in the clefts, arches and pouches grows and migrates to create structures of the head and neck which is essentially completed by the 7th week of gestation.

Anatomical Divisions of the Head and Neck

The neck is divided into a number of triangles bounded by various anatomical landmarks.  These include the submental, submandibular, carotid, muscular, occipital and subclavian triangles and are bounded by the following:

Submental – bilateral anterior bellies of the digastric muscles and the hyoid bone.  This is a midline triangle and therefore does not exist bilaterally like the other triangles.

Submandibular – anterior belly of the digastric muscles, posterior belly of the digastric muscle, and the mandible.

Carotid – posterior belly of the digastric, superior belly of the omohyoid, sternocleidomastoid muscle.

Muscular – superior belly of the omohyoid, sternocleidomastoid muscle and the midline.

Occipital – sternocleidomastoid muscle, trapezius muscle, inferior belly of the omohyoid muscle.

Subclavian – sternocleidomastoid muscle, clavicle, inferior belly of the omohyoid muscle.

The neck is also divided into six lymph node levels each draining specific anatomical sites of the head and neck and are as follows:

Level 1 – submental and submandibular nodes draining from lips, tongue, floor of mouth, gums, and mucosa of cheek.

Level 2 – upper jugular nodes – located anterior to sternocleidomastoid muscle, spanning from skull base to the level of the carotid bifurcation.  Drains nasopharynx and oral cavity.

Level 3 – Mid jugular chain - located along internal jugular vein from the level of the carotid bifurcation to the level of the inferior belly of the omohyoid muscle.  This level is responsible for draining the oral cavity, the pharynx, and the larynx.

Level 4 – Lower jugular chain – located along the lower jugular vein from the level of the inferior belly of the omohyoid muscle down to the clavicle.  This level is responsible for draining the thyroid, piriform sinuses and upper esophagus.

Level 5 – nodes located in the posterior triangle (posterior to the sternocleidomastoid muscle) are responsible for draining the nasopharynx, the posterior scalp, ear, temporal bone, and skull base.

Level 6 – nodes are located in the midline anterior neck and receive drainage from the skin and musculature of the anterior neck.

Differential Diagnosis of the Pediatric Neck Mass

Congenital Neck Masses

Branchial Cleft Cyst

•       Pathophysiology: Developmental alterations of the branchial apparatus results in cysts, sinuses, or fistulas
•       Cysts usually appear from 10-40 yrs of age
•       Sinuses and Fistulas usually appear in 1st decade
•       Different types associated with each cleft
•       Diagnosis: CT with contrast
•       Tratment: Full excision after resolution of any infection

 

First Branchial Cleft Cyst

Type 1

•      Usually Preauricular cyst
•       Duplicated external auditory canal
•       Composed of ectodermal elements only
•       Course: Begins preauricularly then passes laterally to facial nerve then parallels the EAC and ends in a blind sac near the mesotympanum
•      Treatment: Full excision after infection resolution.  May need superficial parotidectomy

Type 2

      More common than type 1

•       Submandibular cyst
•       Duplicated membranous external auditory canal and Pinna
•       Composed of Ectodermal and Mesodermal elements
•       Course: Begins near the mandibular angle then passes laterally or medially to facial nerve and then ends near or into the external auditory canal
•       Treatment: Full excision after infection resolution.  May need superficial parotidectomy

 

Second Branchial Cleft Cyst

•       Cyst along the anterior sternocleidomastoid muscle
•       Most common of the branchial cleft cysts (90-95%)
•       Course: External opening at lower neck which tracks along the carotid sheath and then passes between ext. and int. carotids and lateral to crainial nerves IX and XII and then opens internally at middle constrictors or in tonsillar fossa

 

Third Branchial Cleft Cyst

•       Cyst in lower anterior neck
•       Course: Ext. opening at lower ant. neck  which tracks superficial to CN X and the carotid and then passes over XII and inferior to IX and then pierces the thyrohyoid membrane and opens internally at the upper piriform sinus

 

Fourth Branchial Cleft Cyst

•       Cyst Anterior to the inferior portion of the SCM
• n      Course: Ext. opening anterior to the inferior SCM which tracks superiorly over CN XII and the carotid bifurcation and then passes inferiorly to loop under the aortic arch or subclavian artery and then passes superior to open at the apex of the piriform sinus

 

Lymphovascular Malformations

•     AKA – Lymphangioma or Cystic Hygroma
•     Pathophysiology: abnormal development or obstruction of primitive jugular lymphatics that undergo irregular growth
•       Signs and symptoms: soft, painless, multiloculated, compressible neck mass.
•       Often presents in the posterior triangle (80%)
•      65% are present at birth
•      Lesion transilluminates
•      Diagnosis: U/S, CT or MRI
•      Complications: infection, compressive symptoms, facial deformity
•       Treatment: Spontaneous regression in 15%.  Otherwise medical vs. surgical management
•      Sclerosing agents such as Bleomycin and OK-432 (group A strep with Pen G) can be injected with success rates up to 60%
•      Treatment primarily remains as surgical excision without violation of important structures with recurrence rates from 10-50%
•       More likely to recur if lesion involves multiple sites or involves the aerodigestive tract

 

Dermoid Cysts and Teratomas

•      Pathophysiology: derived from pleuripotent embryonal crest cells
•      Teratoma – composed of all three embryologic layers
•      Dermoid Cyst – ectodermal and mesodermal elements only – midline neck or floor of mouth
•      Teratomoma – differentiated to organ structure (usually fatal)
•       Epignathi – differentiated to body parts (usually fatal)
•     Signs and symptoms: soft, midline neck mass, may be associated with tufts of hair
•      Diagnosis: Biopsy
•     Complications: rare malignant potential, airway compromise
•      Treatment: Excision after resolution of any infection

Thyroglossal Duct Cyst

•       Pathophysiology: Failure of complete obliteration of the thyroglossal duct
•     Signs and symptoms: midline neck mass with cystic and solid components that elevates with tongue protrusion
•     Complications: rare malignant potential, may be the patient’s only thyroid tissue
•      Diagnosis: Clinical /- CT
•      Treatment: Sistrunk Procedure (cyst excision with removal of the middle one-third of the hyoid bone) is associated with the lowest recurrence rate which is about 3%.

 

Thymic Cysts

•      Pathophysiology: remnant of third pharyngeal pouch between angle of mandible and the midline neck
•      Signs and symptoms: Mass along the path of thymus migration
•      Diagnosis: Biopsy, CT/MRI
•      Treatment: Excision

 

Pseudotumor of Infancy (POI) and Torticollis

•       Pathophysiology: intrauterine or birth trauma causing muscle injury, hematoma, and resultant fibrosis of the sternocleidomastoid muscle
•       Unclear distinction between POI and torticollis
•     Signs and Symptoms: the head is turned toward and chin turned away from the affected side
•      Firm thickened mass confined to sternocleidomastoid muscle
•    Diagnosis: Clinical
•     Treatment: observation, passive range of motion exercises, physical therapy, few may require surgical muscle release

 

External Laryngocele

•      Pathophysiology: congenital or acquired expansion of laryngeal saccule (ventricle) from increased intraglottic pressure
•      Signs and symptoms: Lateral, compressible mass that enlarges with intralaryngeal pressure
•      Diagnosis: indirect mirror exam, fiberoptic laryngoscopy, endoscopy, CT
•      Complications: infection, malignant potential
•     Treatment: Marsupialization of the laryngocele, open surgical approach

Infectious Neck Masses

Bacterial Cervical Adenitis

•       Pathophysiology: draining infection causes cellular response in lymph node group(s)
•   Bacterial pathogens often include Group A Strep or S. Aureus (80% of cases), TB, Atypical Mycobacterium
•    Signs and symptoms: Acute development of tender, mobile cervical mass, associated with constitutional symptoms (fever, malaise)
•       Diagnosis: Clinical exam, needle aspiration for culture and sensitivity
•      Treatment: Antibiotics, Incision and drainage for abscess
•       Usually affects only one LN group if bacterial
•     If adenitis adenitis is suppurative or there is liquifactive necrosis it is most likely adenitis of bacterial etiology.

Atypical mycobacterium adenitis

•     Usually caused by Mycobacterium avium-intracellulare but also includes M. chelonei and M. Kansasai
•    Typically presents in children < 5 yrs as slow growing, painless neck nodes at level I and II
•      PPD negative 50% of the time
•      Diagnosis: Fine needle aspiration for culture and sensitivity
•      Treatment: Traditionally surgical with resection or currettage
•      Avoid Incision and Drainage – chronically draining sinuses may occur
•      Recent studies have shown that Macrolide antibiotics can be effective in completely resolving or decreasing adenopathy size in many patients

Cat Scratch Fever

•     Caused by Bartonella Henselae
•      May occur weeks to months after cat bite or scratch
•      Signs and Symptoms: papular lesions at primary site, tender cervical adenopathy (single node), mild fever and malaise
•       Diagnosis: history, culture from lesion, cat-scratch antigen
•       Histology: intracellular, gram negative bacillus, Warthin-Starry stain, central avascular necrosis
•       Treatment: observation with supportive care vs. antibiotics in the immunocompromised.  Incision and drainage should not be performed in order to prevent a chronically draining sinus.

Viral Cervical Adenitis

•      Most common cause of lymphadenitis
•      Pathogens include Epstein-Barr virus, cytomegalovirus, Herpes Simplex, adenovirus, enterovirus, roseola, rubella, HIV, Echovirus, Rhinovirus, respiratory synctial virus
•     Signs and symptoms: similar to bacterial adenitis, lower grade fevers, more indolent course, bilateral involvement, can persist for weeks
•     Diagnosis: history and physical exam
•      Treatment: Supportive

 

Other (more rare) lymphadenitis causes and organisms

•      Tuberculosis – if adenitis is present, this suggests hematogenous spread
•     Syphilis
•     Toxoplasmosis – usually occurs in the posterior cervical triangle and presents with a single enlarged node
•      Tularemia
•      Pasturella Multicida
•      Brucellosis
•      Rat Bite Fever (Spirillum minus)

Endocrine mediated neck masses

Endocrine causes include:

•       Thyroid Hyperplasia – Goiter – Pendred Syndome
•       Thyroid Nodules
•       Aberrant Thyroid Tissue
•     Thyroiditis
•      Parathyroid Cyst
•     Thyroid/Parathyroid Neoplasia

 

Pendred Syndrome

•      Defect in tyrosine iodination
•      Severe to Profound Sensorineural hearing loss
•       Mondini Deformity – developmental arrest of bony and membranous labyrinth – single turn, curved cochlea – no interscalar septum
•       Multinodular goiter at 8-14 years old caused from failure of iodine organification
•       Diagnosis: Perchlorate Test
•      Treatment: Exogenous thyroid hormone, thyroidectomy is typically not needed, amplification or cochlear implant for the sensorineural hearing loss.

Pediatric Neoplastic Neck Masses

Benign Neoplasms include:

•      Neurogenic Tumors (neurofibromas & schwannomas)
•      Thyroid/Parathyroid Neoplasia
•       Hemangioma/Vascular tumor
•      Salivary Gland Tumor
•      Teratoma

Malignant Neoplasms include:

•      Lymphoma (both Hodgkin’s and Non-Hodgkin’s)
•      Sarcomas
•      Thyroid Carcinoma (Men IIa/b)
•      Nasopharyngeal Carcinoma
•      Neuroblastoma
•      Salivary Gland Malignancy
•      Malignant Teratoma

 

The likelihood of the pediatric neck malignancies can be stratified by age group and is as follows:

•       < 6 yrs: Neuroblastoma > non-Hodgkin’s > Rhabdomyosarcoma > Hodgkin’s
•       7-13 yrs: Hodgkin’s = non-Hodgkin’s > thyroid carcinoma > rhabdomyosarcoma
•       Adolescents: Hodgkin’s Lymphoma

 

Neuroblastoma

•       Malignancy of the sympathetic nervous system
•      Patients are usually less than 10 yrs old, peak incidence at 2 yrs
•      Primary head and neck tumor presents as a painless neck mass
•      60% have metastasis at presentation – bone, lung, liver, spleen
•       Associated with elevated urine catacholamines (VMA)
•       Treatment: Excision for localized disease, Chemotherapy for residual or metastatic disease
•      Adjuvant radiation treatment is useful in unresectable disease

Lymphomas

Non-Hodgkin’s

•       Usually < 13 yrs old
•       Extranodal involvement (Waldeyer’s ring)
•       Associated with AIDS and EBV
•      Includes Burkitt subtype
•      Diagnosis: Biopsy
•      Treatment: Chemotherapy, radiation treatment is reserved for emergency situations.

 

Hodgkin’s

•      Teenagers
•      Primarily nodal disease – 80% present with cervical lymphadenopathy
•      Associated with EBV
•      Reed-Sternberg cells on histology
•      Diagnosis: Excisional biopsy, Bone Marrow biopsy
•      Treatement: combination chemotherapy and radiation

 

 

Rhabdomyosarcoma

•      Most common pediatric soft tissue sarcoma
•       Only about 250 cases in US per year
•       Around 1/3 occur in the head and neck
•       50% Skull base, 25% Orbit, 25% other sites
•       Rarely involve cervical lymphatics
•      Diagnosis: Biopsy
•      Tx: complete excision if possible, neoadjuvant or adjuvant chemotherapy and possible radiation based on prognosis
•      Prognosis depends on tumor site, extent of tumor resection, and histological subtype of tumor
•      Chemotherapy: vincristine, actinomycin D, cyclophosphamide (VAC)

 

Thyroid Malignancy

•       Uncommon in pediatric population
•       Usually occurs in the group > 10 yrs old
•      Presents with asymptomatic firm and mobile anterior neck mass
•      Palpable cervical lymph nodes in 75%
•     5-10% have lung metastasis at the time of presentation
•      Pathology: Papillary > Follicular > Medullary
•      Diagnosis: FNA or Excisional biopsy with lobectomy
•      Tx:

–        Near total or total thyroidectomy

–        Functional Neck Dissection if neck disease present

–        Possible I¹³¹ – radioactive iodine ablation

Medullary Thyroid Carcinoma

•      25-30% of Medullary carcinomas are familial:

–        MEN 2A - hyperparathyroidism, pheochromocytoma

–        MEN 2B - mucosal neuromas, marfanoid features

–        Familial Medullary Thyroid Carcinoma

•       > 90% of patients with MEN type 2 mutation will develop medullary thyroid carcinoma at some point
•      Diagnosis/treatment: All medullary carcinoma patients need genetic screening for MEN type 2 and if positive, the patient’s family members need to be screened

–        MEN 2A - should undergo thyroidectomy at around 6 yrs

–        MEN 2B - should undergo thyroidectomy shortly after birth

 

Parotid Masses

•      In the pediatric population these are uncommon and consist of various lesions
•      Although less common than in adults, childhood parotid neoplasms have higher incidence of malignancy
•       Signs and symptoms: Obvious mass that swells or is enlarging
•      Most commonly located in the preauricular area, followed by the tail of the gland
•      Diagnosis: FNA has high sensitivity and specificity for pediatric parotid lesions
•      For non-diagnostic FNA’s or poor patient tolerance of FNA, surgical excision is an option
•      The differential diagnosis includes inflammatory, benign and malignant masses:

§         Pleomorphic Adenoma

§         Chronic sialadenitis with or without abscess

§         Hemangioma

§         Mucoepidermoid carcinoma

§         Inflammatory lymph nodes

§         1st Branchial cleft cysts

§         Lymphangioma

§         Acinic cell carcinoma

§         Adenoid cystic carcinoma

§         Lymphoma

§         Neurofibroma

§         Adenocarcinoma

•      Treatment

§         Infectious or inflammatory lesions that do not respond to conservative treatment, require surgical intervention

§         Parotid surgery in the pediatric population is associated with minimal morbidity

§         Appropriate surgical treatment results in low recurrence rates and few complications

§         Limited procedures increase risk of recurrence – recommendation for superficial parotidectomy for benign lesions and total parotidectomy for malignancy

§         Complications include Frey’s syndrome and hypertrophic scarring

Systemic/Other causes of the pediatric neck mass

•      Kawasaki Disease
•     Laryngocele
•     Plunging (Diving) Ranula
•       Rosai-Dorfman Disease

Kawasaki Disease

•      AKA mucocutaneous lymph node syndrome
•      Unknown etiology
•      Causes acute vasculitis of multiple organ systems in children
•      Signs and symptoms: High fever, cervical lympadenopathy, conjunctivitis, red or dry blistering lips, rash, “strawberry tongue”, anterior uveitis, oropharyngeal mucosal hyperemia, perianal erythema
•      Treatment: IV immunoglobulin and ASA or dipyridamol (coronary aneurysms)

Plunging (Diving) Ranula

•      Mucous retention cyst of the floor of the mouth, usually from the sublingual gland that extends into the cervical tissues
•      Signs and symptoms: cystic mass on floor of mouth, lip, buccal mucosa, or minor salivary gland
•      Diagnosis: Clinical History and Exam, excisional bx
•      Treatment: Excision or marsupialization

 

Rosai-Dorfman Disease

•       Sinus histiocytosis with massive lymphadenopathy (SHML)
•      First described by Robb-Smith in 1947
•      Symptoms: Massive painless bilateral cervical lymphadenopathy with fevers, occurs in the second decade
•      25% with extra-nodal disease including upper respiratory tract, salivary glands, orbit, testis and other sites
•       Diagnosis: Histology
•     Natural history: regression and resurgence followed eventually by complete resolution
•      Unknown cause and no treatment shown to be of benefit
•      Consider surgical intervention for compressive symptoms

Neck Mass Work Up

     Thorough History and Physical: age, location, duration, mobility, constitutional symptoms

•      Appropriate use of imaging, serology, cultures and biopsy (including FNA) can aid in diagnosis
•      Use clinical judgment and experience to tailor work-up
•      Differential diagnosis based on location:

§         Lateral

§         Branchial Anomalies

§         Laryngocele

§         Thymic Cyst

§         Pseudotumor of infancy

§         LAD

 

§         Midline

§         Thyroglossal Duct Cyst

§         Dermoid Cyst

§         Plunging Ranula

§         Teratoma

 

§         Entire Neck

§         Hemangioma

§         Lymphatic Malformation

 

§         Local infection and neoplasms can present at any location in the neck

 

 

Concluding Comments

•      Many disease processes can manifest as a neck mass in the pediatric population
•      History, Physical Exam, and Clinical Judgment should help to initially categorize a neck mass
•     FNA and imaging are important tools for diagnosis
•      Surgery becomes important not only for definitive treatment of certain neck masses, but also as part of the work up for malignancy

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