Pediatric Neck Masses
Pediatric neck masses are a common reason for a child to visit a pediatrician's office or emergency department. They are often categorized as congenital, inflammatory, or neoplastic. The vast majority of neck masses are inflammatory with up to 40% of infants and 55% of children having palpable benign cervical lymph nodes. The goal of this article will be to discuss the workup of a pediatric neck mass to aid in diagnosis, describe the most common types of neck masses, and briefly review management for many of these masses.
History As with the workup of any new patient, an accurate history can lead to a correct diagnosis most of the time. The age of onset of the mass, symptom duration, associated symptoms, and progression in size are all pertinent pieces of the history. Determining the age of onset helps delineate a congenital mass from an acquired mass. Associated symptoms such as pain would point to an inflammatory lesion. The presence of any degree of airway obstruction would warrant prompt treatment. A mass that progresses in size over the course of days is consistent with an inflammatory process, whereas rapid growth over weeks may be concerning for a malignancy. Recent travel is important to know especially in the case of scrofula (cervical tuberculosis). Environmental exposures to cats or contaminated water, for example, may lead to a diagnosis of cat-scratch disease or atypical mycobacterium, respectively. Finally, the presence of constitutional symptoms such as fever, weight loss, night sweats, or vomiting may favor a malignancy.
Physical Exam Critical elements of the physical exam include location in the neck, presence of skin changes, mobility of the mass, presence of tenderness, and size. Location is probably the most crucial part of the exam that can narrow down a diagnosis. Midline neck lesions in children are most commonly thyroglossal duct cysts, dermoid cysts, or benign lymph nodes. Antero-lateral masses may be consistent with branchial cleft cysts, lymphangiomas, or metastatic thyroid lymphadenopathy. Supraclavicular and posterior triangle masses may be worrisome for malignancy. Finally, lymphadenitis and lymphangiomas can cross all boundaries in the neck. Fluctuance or erythema of the skin is present mostly in inflammatory lesions and mobile lesions tend to be benign. Lesions less than one centimeter are consistent with benign lymph nodes and tenderness can denote an inflammatory process. Other head and neck findings are important to note as well. For example, tonsillar enlargement with exudates in the presence of cervical lymphadenopathy may be consistent with infectious mononucleosis.
Laboratory Tests While exhaustive laboratory testing is not recommended, certain tests can point to certain diagnoses. If an inflammatory/infectious process is suspected, CBC with differential and a CRP value can help determine the severity of inflammation. A PPD is often recommended as well to rule out tuberculosis or even atypical mycobacterium. Bartonella titers can be drawn from patient serum to diagnosis cat-scratch disease.
Imaging The three most common imaging modalities used in evaluation of head and neck masses are ultrasound, CT scan, and MRI. Neck ultrasound is a great initial screening tool because it is minimally invasive, lacks radiation exposure, does not require sedation, and is low in cost. Ultrasounds are able to distinguish cystic from solid lesions, approximate size of the lesion, and accurately evaluate the thyroid gland. In addition, it is a critical tool to assess the presence of normal thyroid tissue in its normal location during the workup of a thyroglossal duct cyst. Serial ultrasounds may also be used to follow the size of a benign appearing lymph node or nodes in neck if observation is the chosen treatment plan. Despite the many advantages of ultrasound imaging, there are several limitations. Accuracy of the exam is dependent upon the experience of the technician performing and interpreting the scan. Additionally, resolution and detail are inferior to CT or MRI and one is limited by the air-soft tissue interface and by bone. Nevertheless, ultrasound imaging tends to be underused as an initial imaging tool because of the availability of the CT scan. CT imaging can clearly delineate vital structures in the neck (neurovascular bundle) in relation to the lesion. A CT scan is the most common modality used to evaluate deep space neck infections and can be critical for surgical planning in any head and neck procedure. CT scan imaging is also most preferred when optimal bony resolution is required. However, radiation exposure is a concern with CT scan imaging so judicious use is important. MRI imaging is preferred for soft tissue lesions and neurovascular structures while delineating soft tissue planes where bone involvement is not a concern, such as in lymphangiomas or vascular malformations. MRI is no better than CT in detecting cellulitis or neck abscesses. In summary, ultrasound is a great initial screening that is often underutilized to evaluate cystic lesions, the thyroid gland, and lymphadenopathy. CT scan imaging is important for surgical planning, but premature use should be avoided due to cost and radiation exposure.
Fine Needle Aspiration and Biopsy Fine needle aspiration (FNA) can be used to potentially diagnose thyroid malignancies, lymphomas, or rhabdomyosarcomas with cervical involvement. However, this test is under utilized in children primarily due to non-compliance. Except in possibly the adolescent population, sedation would often be required to successfully complete FNAs in children. Additionally, the role of FNA in thyroid nodule evaluation in children is under investigation and may have a limited role since pediatric thyroid nodules have a higher incidence of malignancy compared to adults and would often require lobectomy or thyroidectomy. Finally, ultrasound-guide FNA can be therapeutic when used to aspirate deep neck abscesses or fluid collections.
Excisional open biopsy is indicated to rule out malignancy in cases of supraclavicular adenopathy, fixed lesions, rapidly growing masses in the absence of inflammation, or a persistent mass in the presence of constitutional symptoms.
Inflammatory Masses Inflammatory masses are the most common pediatric neck masses encountered. They can be further subdivided into infectious and non-infectious processes. Infectious neck masses may include viral adenitis, bacterial lymphadenitis, atypical mycobacterium, cat-scratch disease, or mononucleosis. Non-infectious neck masses may include a plunging ranula, preauricular cyst, or adenopathy associated with Kawasaki's disease. This article will focus on the more common infectious head and neck masses.
Viral cervical adenitis, the most common type of cervical lymphadenopathy, is self-limited and does not warrant biopsy. It may be a result of adenovirus, rhinovirus, influenza, varicella, herpes or measles. Treatment typically only requires supportive measures. Mononucleosis may present with bilateral posterior cervical adenopathy in the presence of tonsillar enlargement with white exudates. A positive Epstein Barr Virus antibody titer and monospot test is diagnostic and treatment is also supportive with hydration , rest and IV steroids.
Bacterial lymphadenitis, a common indication for hospitalization, is characterized by a recent upper respiratory infection, fever, and tender adenopathy. While the submandibular, retropharyngeal and superior deep cervical nodes are most often involved, bacterial adenitis can affect any lymph node group in the neck. Staphylococcus aureus (80%) and group A beta-hemolytic streptococcus (15%) are the most common pathogens leading to suppuration with a rising incidence of methicillin-resistent staphylococcus aureus in the community. Evaluation of bacterial lymphadenitis involves identifying an erythematous, tender, enlargening neck mass with or without fluctuance. Elevated white blood cell count and C-reactive protein is a common finding but not necessary for diagnosis. Ultrasound is recommended as an initial imaging test to determine size and the presence of fluid (indicating abscess formation). CT imaging, which provides the best resolution for deep neck infections, is advised if there is no clinical improvement after initial treatment, minimal skin changes without obvious fluctuance, or for definitive surgical planning. Needle aspiration can be both diagnostic (culture and sensitivity) and therapeutic if an abscess cavity is present. Management of bacterial neck infections can involve oral antibiotics, IV antibiotics and/or surgical drainage. A trial of oral antibiotics is indicated as an initial treatment when only mild systemic symptoms and skin changes are present. A ten day course of a beta-lactamase resistant antibiotic is recommended. IV antibiotics are indicated in the presence of high fevers, poor PO intake, and marked enlargement of lymph nodes with cellulitis. Phlegmon or minimal suppuration seen on CT scan also predicates the need to initiate IV antibiotic therapy. Double coverage with clindamycin and cefftriaxone is a common regimen. Lack of improvement on IV antibiotic therapy over 48-72 hours or progression in size or fluctuance necessitates CT imaging, if not already done, or immediate surgical incision and drainage. Following surgical drainage, culture driven PO antibiotics are initiated for 10 to 14 days.
Cat scratch disease has an incidence of 9.3/100,000 which presents with cervical adenopathy weeks after inoculation by contact with cats. Children may have fever and malaise and only up to 30% of the nodes may suppurate. Definitive diagnosis is by serology with positive Bartonella hensalae titers. Treatment is primarily supportive but may include a short course of a macrolide antibiotic.
Atypical mycobacterium, the leading cause of cervical tuberculosis in children, affects kids between the ages of 1 and 5. The most common pathogen is Mycobacterium avium-intracellulare and inoculation is from contaminated food, water, or soil. Patients often lack systemic symptoms and present with a < 3 cm lateral submandibular neck mass that may display violaceous skin changes. The mass may spontaneously rupture leading to a draining sinus tract. PPD ought to be placed however a positive result is not needed for diagnosis. Definitive management consists of complete surgical excision and curettage with 1-6 months of antibiotics. A macrolide antibiotic and rifampin are often administered, however type and duration of antibiotic that ought to be used is not clearly defined. There is some thought that atypical mycobacterium infections will resolve on their own regardless of the treatment employed. Nevertheless, it is advised never to perform incision and drainage of the lesion due to a resulting chronically draining sinus tract.
Congenital Masses Congenital neck masses may include thyroglossal duct cysts, dermoid cysts, lymphangiomas, branchial cleft cysts, teratomas or congenital muscular torticollis. Vascular processes such as venous malformations and hemangiomas are also often included in this category but will not be discussed here.
Thyroglossal duct cysts are the most common midline neck mass and second most common overall neck mass after benign lymphadenopathy. They are responsible for 70% of all congenital neck lesions. The thyroglossal duct forms as the thyroid diverticulum descends from the floor of the pharynx to eventually form the thyroid gland in the anterior neck. While the duct typically obliterates, any persistence of the duct along it's path of descent can lead to a thyroglossal duct cyst. The cysts can occur anywhere near the central portion of the hyoid bone. The lesions may present in children or in adolescence as painless midline masses that elevate with swallowing or tongue protrusion. Part of the workup of thyroglossal duct cysts should include an ultrasound to evaluate its structure and confirm that normal thyroid tissue exists in the neck. The cysts can become infected with or without fistula formation and would require antibiotics or needle aspiration to treat. Definitive management of the cysts requires a Sistrunk procedure which involves complete excision of the cyst with the central 2/3 of the hyoid bone and tract leading to the base of tongue. Incomplete resection is a common cause of recurrence.
Dermoid cysts are the second most common midline neck mass and unlike thyroglossal duct cysts, they do not elevate with swallowing since these lesions are only attached to the dermis. Cervical dermoid cysts are comprised of ectodermal and mesodermal germ cell layers and may contain epithelial appendages such as hair or sebaceous glands. These masses do not get infected but because of their potential for enlargement, surgical excision is recommended. Teratomas differ from dermoid cysts in that they are composed of all three germ layers: ectoderm, mesoderm, and endoderm and are typically much larger. Cervical teratomas are present at birth and are often detected in utero, necessitating careful planning for a safe delivery due to potential airway obstruction. CT or MRI is the imaging modality of choice and surgical resection is mandatory.
Lymphatic malformations (cystic hygroma) are congenital malformations formed from blocked lymphatic ducts that fail to drain into the venous system. This results in multiple dilated sacs of lymph fluid. Up to 70% are present at birth and most are evident by 2 years of age. These masses are soft, compressible, non-tender and may extend to any neck level. They can be best evaluated by CT or MRI. Treatment consists of observation, injection of sclerosing agents, or surgical resection. Surgical resection is recommended in the presence of airway compromise, or significant cosmetic deformity. Recurrence rate is high even following surgical resection.
Branchial cleft abnormalities lead to up to 30% of all congenital neck masses. The anomalies are a result of disturbances in the development of the branchial apparatus. There are five branchial arches comprised of ectoderm, endoderm , and mesoderm which give rise to many of the structures in the head and neck. Clefts arise from ectoderm between each arch and typically obliterate through development, however the failure of these clefts to obliterate leads to cysts, sinuses, or fistulas. First branchial cysts are classified as type I and type II. Type I lesions are duplications of the external auditory canal and may present as fistulas inferior to the earlobe, but rarely as cystic masses. Type II lesions may present as cystic masses inferior to the the angle of the mandible and anterior to the sternocleidomastoid (SCM) muscle. Second branchial cleft cysts are the most common, comprising more than 90% of all anomalies and present as masses along the anterior border of the SCM. These lesions may not present until late childhood or adolescence. They can also become infected with oral flora since many have tracts that lead to the tonsillar fossa in the oropharynx. Type III and IV branchial cleft cysts are rare but present as neck swellings at the lower anterior border of the SCM or as recurrent thyroid abscesses since they both intimately associated with the thyroid gland. Many of these lesions have sinus tracts that open near the piriform sinus near the larynx. The definitive treatment for all branchial cleft anomalies is surgical excision including all fistula tracts. Cauterization of tracts near the piriform sinus has been shown as an effective treatment to prevent recurrent neck infections in type III/IV brachial cleft anomalies.
Congenital muscular torticollis, also known as sternocleidomastoid tumor of infancy , is a benign condition presenting as a mass in the SCM during the neonatal period due to hematoma formation in the body of the muscle as a result of birth trauma. Infants have their heads tilted to the ipsilateral side and chin pointed in the opposite direction. Ultrasonography confirms the presence of a solid mass in the SCM and initial treatment consists of physical therapy with passive exercises of the neck. Lack of response to conservative measures warrants surgical partial division of the SCM.
The most common manifestation of a pediatric head and neck malignancy is an asymptomatic neck mass. Fifty percent of all primary infantile malignancies originate in head and neck and twenty-five percent of all pediatric malignancies eventually involve the head and neck. As a result, any high degree of suspicion for a presenting neck mass should warrant a biopsy to ensure prompt diagnosis. Potential clinical indicators for malignancy include rapid growth in the absence of inflammation, fixation to underlying structures, skin ulceration, or size > 3 cm. Common pediatric malignancies presenting in the neck are thyroid cancer, rhabdomyosarcoma, and Hodgkin's and non-Hodgkin's lymphoma. All can be fully treated with early detection.
Pediatric neck masses are a common reason for a child to visit the pediatrician. Categorizing the lesions into congenital, inflammatory, or potentially neoplastic while focusing on location in the neck, with judicious use of imaging can help generate a differential to aid in diagnosis. Definitive management of these lesions can then ultimately be achieved by working closely with a pediatric otolaryngologist.