Pediatric Head and Neck Tumors

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What are the categories of neck masses in children that are important when creating a differential diagnosis?

• Congenital neck masses are those that are present at birth and secondary to defects occurring in embryology.

• Infectious neck masses are those that present due to an infection and typically resolve with treatment of the infection. These are most commonly infected or reactive lymph nodes but can also occur in other tissues in the head and neck such as the salivary glands.

• Inflammatory masses that do not have a known infectious cause such as those associated with Kawasaki’s disease.

• Neoplastic lesions of the neck including benign and malignant processes. These encompass malignant lymphadenopathy, benign and malignant salivary gland tumors, benign and malignant thyroid tumors, and tumors originating from neurologic, muscular, vascular, lymphatic, cartilaginous, or osseus tissues.

• Vascular malformations (see Chapter 54 ).

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Which is the most common neck mass in children?

An enlarged lymph node is the most common reason that a child presents with a neck mass. The most common cause of enlarged lymphadenopathy is infection, either viral or bacterial. Viral causes of lymphadenopathy include adenovirus, rhinovirus, and enterovirus, which can all occur with a viral upper respiratory infection. Epstein-Barr virus causes mononucleosis, which consists of cervical lymphadenopathy, exudative tonsillitis, and hepatosplenomegaly.

Bacterial causes of an enlarged lymph node most commonly include infections due to Staphylococcus aureus and Streptococcus pyogenes . Sometimes, the infected lymph node can suppurate and create a neck abscess. Other significant causes of bacterial lymphadenitis are atypical mycobacterium, Bartonella henselae (cat-scratch disease), and tuberculosis.

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Which presenting features suggest an acute infectious cause of a neck mass?

Fever, pain, acute swelling, erythema of the overlying skin, decreased neck range of motion, and odynophagia can indicate that a neck mass is secondary to an infectious cause. Concomitant upper respiratory tract symptoms, exposure to sick contacts, foreign travel, exposure to animals (cats, ticks), and the presence of immunodeficiency are all important historical features that can allow better understanding of the etiology of a neck mass.

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Which other type of neck lesions can present with an acute infection or inflammation?

Congenital lesions including thyroglossal duct cysts, dermoid cysts, branchial cleft cysts, vascular malformations, and preauricular cysts can often present with acute swelling, erythema, pain, and fevers. The preferred treatment of these infectious exacerbations is antibiotic therapy. Incision and drainage should be performed only if necessary because they may complicate the definitive resection of the congenital mass. The resection of a congenital lesion is more easily accomplished after complete resolution of the infection.

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Which congenital neck masses occur in the midline neck?

Thyroglossal duct cyst is the most common congenital neck mass. Thyroglossal duct cysts occur in the midline due to incomplete obliteration of the thyroglossal duct. The median thyroid anlage starts at the foramen cecum of the tongue and migrates caudally in the neck until it reaches its final anatomic position near the cricoid cartilage. The thyroglossal duct should obliterate, but occasionally this process is incomplete. A cyst can then form at that location with a tract that connects the cyst to the foramen cecum. Ectopic thyroid tissue can occur anywhere from the foramen cecum to the normal position of the thyroid gland.

Dermoid cysts are benign cystic structures that can occur anywhere in the body. They frequently occur in the head and neck and can occur in the midline neck and mimic a thyroglossal duct cyst. Other common locations include the nose, oral cavity, orbit, and nasopharynx. Dermoid cysts arise due to entrapment of epithelial cells along lines of fusion. They usually contain other skin appendages including sebaceous glands, hair, or hair follicles. They can often be adherent to the overlying skin and may even have a small draining sinus.

Teratomas are similar to dermoid cysts, with the exception that they contain cell types of ectodermal, mesodermal, and endodermal origin. They may present as a firm neck mass and can cause respiratory symptoms when they are very large. Treatment requires complete surgical excision.

Laryngoceles occur as midline neck masses when they herniate through the thyrohyoid membrane (external laryngocele). If confined to the larynx, it is an internal laryngocele and will not likely present as a mass. Symptoms include hoarseness, dysphagia, and severe dyspnea, particularly when presenting in a neonate.

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What is the significance of the Sistrunk procedure used to resect a thyroglossal duct cyst?

The earliest reports of thyroglossal duct cyst excision were plagued by a rate of recurrence as high as 50%. Resection of the hyoid bone along with cyst improved recurrence rates to 20%. Walter Sistrunk expanded that technique to include resection of the cyst, hyoid bone, and suprahyoid tongue musculature to ensure that the tract(s) connecting the cyst to the foramen cecum was adequately resected. This decreased the recurrence rate to near 5%. Removal of the cuff of lingual musculature is important because the tract may pass anterior or posterior to the hyoid and may be multiple.

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