Section 4: Neck

Patient Story

A 6-year-old boy is brought to his pediatrician with a 2-day history of fevers and cough. During the exam, the pediatrician notes a mass in the neck. His father first noticed it this morning. The mass is approximately 2 × 2 cm in size and located at the level of the hyoid in the midline of his neck (Figure 32-1). It is well circumscribed, with erythematous, and tender overlying skin. The mass moves when the boy swallows. The pediatrician suspects a thyroglossal duct cyst and refers to pediatric otolaryngology. The surgeon recommends complete excision to the father. After the upper respiratory infection has resolved, the thyroglossal duct cyst is removed completely under general anesthesia with no complications. The boy recovers completely.

Introduction

Thyroglossal duct cyst is a congenital neck mass that occurs during development, as the thyroid descends from the base of the tongue to its paratracheal location.

Synonyms

Ectopic cervical thyroid.

Epidemiology

• It is reported that 7 percent of the population have thyroglossal duct cysts.¹

• The most common congenital anomaly of the neck in children, representing more than 75 percent of congenital midline neck masses.²

Etiology and Pathophysiology

• Between the 3^rd and 4^th week of gestation, the thyroid gland descends from the base of tongue to its paratracheal location and remains connected by the thyroglossal duct, which involutes between the 7^th and 10^th week. Failure to involute results in persistence of a portion of this duct, which is known as a thyroglossal duct cyst.

• Thyroglossal duct anomalies commonly present when they become acutely infected as a tender mass in the midline neck near the level of the hyoid. It is postulated that lymphoid tissue of the neck close to the thyroglossal structures reacts to repeated upper respiratory infections and this infectious irritation may stimulate epithelial remnants to undergo cystic change.³

Risk Factors

• There are no risk factors identified that predispose a child to acquiring this mass.

Diagnosis

A good history of the present illness is paramount in the diagnosis and management of a neck mass. Important details include age that the mass was first noted, clinical signs, rate of growth and constitutional symptoms, recent travel outside of the US, and cat exposure.

Clinical Features

• Typically presents after an upper respiratory infection as a painful, erythematous, and tender midline neck mass (Figures 32-1 and 32-2).

• It can also appear as a mobile, painless mass in the midline of the neck.

• Associated symptoms that may develop include fever, dysphagia, dysphonia, and/or a discharging sinus.

• Average size is 2 to 4 cm in diameter.

• Movement of the cyst with swallowing is often cited as a reliable diagnostic sign because of the thyroglossal duct’s close association with the hyoid bone and foramen cecum.⁴

Laboratory Testing

• A complete blood count may be useful in identifying an infectious etiology.

• Other laboratory tests that are not particularly required for the evaluation of a midline neck mass but may be helpful in the work-up of other pediatric neck masses are:

  • Bartonella titers—To rule out cat scratch disease.

  • Toxoplasma titers.

  • Cytomegalovirus (CMV) titers.

  • Epstein-Barr virus (EBV) titers.

  • Monospot.

Imaging

• Ultrasonography is the investigation of choice for a clinically suspected thyroglossal duct cyst (Figure 32-3). It is helpful prior to removal of the cyst to ensure that there is normal thyroid tissue and that the cyst does not represent an ectopic thyroid.

• CT and MRI play a supplementary role to more accurately delineate the anatomy of large cysts, and MRI may be utilized to define a residual sinus tract in cases of recurrent disease.

Differential Diagnosis

• Mass location may help determine the diagnosis:

  • Midline neck mass.

    • Dermoid—Epithelium entrapped in tissue during embryogenesis. Dermoids are usually attached to the skin.

  • Lateral neck mass.

    • Branchial cyst—Second most common congenital neck mass, which arise from incomplete obliteration of the pharyngeal pouches and clefts during embryogenesis (Figure 32-4).

    • Represents 20 percent of congenital pediatric head and neck masses.⁵

    • Similar clinical presentation as thyroglossal duct cyst—Usually presents after an upper respiratory infection as a painful, erythematous neck mass.

    • Imaging and diagnostic work up similar to thyroglossal duct cyst.

    • Treatment is complete surgical excision (Figure 32-5).

  • Cystic lymphangioma:

    • Most common lymphatic malformation, usually soft, and fluctuant (Figure 32-6).

    • Represents a congenital hamartomatous malformation of the lymphatic system that typically presents during infancy, and has a tendency to grow unless it is completely excised.

    • About 75 percent of all cases are localized in the neck region.⁶

    • Imaging and diagnostic work up similar to thyroglossal duct cyst.

    • Treatment of choice is complete surgical excision.

• Entire neck.

  • Hemangioma—Represents the majority of vascular tumors and present as red or bluish soft multi-locular masses (Figure 32-7).

  • Venous Malformation—Lesion that is made up of dilated veins in a disorganized fashion, which readily expand in a dependent position and with raised venous pressure (Figure 32-8).

  • Inflammatory adenopathy: most common cause of pediatric cervical adenopathy that comprises a wide variety of clinical conditions (see Chapter 33, Lymphadenopathy).

Management

Nonpharmacologic

• At the time of presentation, treatment of any acute infection, basic lab work, and possibly imaging would be appropriate first steps.

• Once the infection has resolved, imaging, if not already obtained, can be acquired.

Medications

• There are no medications that can treat a thyroglossal duct cyst. However, medical treatment of an infection prior to surgical resection is reported to help decrease the rates of post-surgical recurrence.⁷ SOR B

Surgery

• Complete excision is the treatment of choice. Removal of the entire cyst including the central portion of the hyoid bone and focused tongue base excision of the foramen cecum (commonly known as the Sistrunk procedure) is necessary.⁴ SOR B

Referral

• Referral to Pediatric otolaryngology is advised when the diagnosis is made or suspected.

• Neck masses that have not resolved with antibiotics may warrant otolaryngology consultation.

Prognosis

• Following complete excision of the thyroglossal duct cyst with the Sistrunk procedure, patients frequently do very well.

• Recurrences after Sistrunk operation are reported to occur in 0 to 12.2 percent of patients, in the most recent literature.^8,9

• Failure to surgically excise the thyroglossal duct cyst can lead to repeated infections, dysphagia, dysphonia, and/or draining sinus.

Follow-Up

• Only routine follow-up is needed following surgery, provided there is no further evidence of infection or clinical evidence of recurrence.

Patient Story

A 2-year-old girl presented to her pediatrician with a one month history of swollen glands in her neck and under her arms. Physical examination revealed non-tender firm lymphadenopathy in the anterior and posterior lymph node chains bilaterally (Figure 33-1). Work-up revealed anemia, neutropenia and thrombocytopenia. Biopsy of the lymph nodes and bone marrow biopsy showed acute lymphoblastic leukemia. She underwent induction chemotherapy and has responded well.

Introduction

Lymphadenopathy refers to nodes that are abnormal in either size, consistency, or number. In children, causes of lymphadenopathy can be divided into two large groups-inflammatory versus malignant. Cervical adenopathy due to inflammatory causes is by far the most common. Malignancy is less common but must be considered in the differential diagnosis based on certain concerning features in the history and physical exam.

Synonyms

Lymphadenitis, lymph node enlargement.

Epidemiology

• Almost all children develop lymphadenopathy at some point during childhood with nearly 2/3 of them developing enlarged nodes within infancy.²

Etiology and Pathophysiology

• Lymph nodes are organized centers of immune cells that filter antigenic material such as infectious agents from lymphatics draining from areas of inflammation.

• When activated due to infection or antigenic stimulation, the nodes enlarge in size largely due to proliferation of cells intrinsic to the node such as plasma cells, macrophages, and others.

• Enlargement of nodes can also occur due to infiltration of malignant cells.²

Risk Factors

• Risk factors for inflammatory causes of lymphadenopathy are most commonly associated with exposure to pathogens.

• Viral illnesses that lead to lymphadenopathy are common in childcare centers.

• Parasitic and atypical infections can occur from a variety of exposures, including Bartonella henselae infection from a cat scratch and toxoplasmosis from exposure to cat feces.

• Lymphadenopathy associated with human immunodeficiency virus (HIV) infection can result from perinatal exposure, exposure to intravenous drug use, or unprotected sexual behavior.

• Certain infectious etiologies of lymphadenopathy can be regional in nature, such as exposure to coccidiomycosis in the southwest US and histoplasmosis exposure in the southeastern or central US.

• Medications, such as phenytoin or penicillin, can be associated with the development of lymphadenopathy.

• Odontogenic infections may cause a lymphadenopathy adjacent to the site of the infection.

• Risk factors for malignant causes of lymphadenopathy include exposures to Epstein-Barr virus (EBV) in cases of lymphoma or nasopharyngeal carcinoma.

Diagnosis

Clinical Features

• Localized lymphadenopathy occurs in 75 percent of the cases and generalized lymphadenopathy in the rest of the cases.

• Of all the locations that localized lymphadenopathy can occur, head and neck manifestation occurs in 55 percent of the cases.¹

• Acute unilateral adenopathy is most likely due to streptococcal, staphylococcal, or viral infections (Figures 33-2 and 33-3).

• Acute bilateral adenopathy tends to be due to systemic infections, such as infectious mononucleosis or viral upper respiratory infections (Figure 33-4).

• Subacute or chronic lymphadenopathy usually occurs due to slow-growing bacterial or viral infections such as cat-scratch disease or nontuberculous mycobacterial infection (Figures 33-5 and 33-6).

• Inflammatory masses are generally tender and mobile. Exceptions include some of the causes of subacute or chronic lymphadenopathy, such as nontuberculous mycobacterial infection, which is usually a nontender lymphadenopathy with fixation of the node to the skin (see Figure 33-5 and 33-6).

• Features that may raise concern for the possible presence of malignancy include persistent nontender adenopathy with a size greater than 2 cm, constitutional symptoms such as fevers, night sweats, or weight loss, and adenopathy in certain unusual locations such as the supraclavicular region and in some cases, the posterior neck.³

• In addition, firm, rapidly enlarging, fixed nodes should alert concern for malignancy (Figure 33-7).

Distribution

• Lymphadenopathy can be divided into level I including submental and submandibular nodes; level II, III, and IV, which include superior, middle, and inferior internal jugular nodes, respectively; level V, which is the posterior triangle, level VI which are the jutavisceral nodes; and, finally, level VII, which are nodes in the tracheoesophageal groove.

• Supraclavicular nodes have traditionally been felt to have a higher incidence of malignancy than other more common cervical locations and further evaluation should be considered even if the size is less than 2 centimeters.

Laboratory Testing

• Complete Blood Count with differential, serologic testing for EBV, CMV, cat-scratch disease, toxoplasmosis, HIV, and syphilis can be attained based on clinical suspicion.

• Cultures of infected tissue would be helpful in choosing appropriate medications.

• In addition, serum Lactate Dehydrogenase (LDH) can be attained in evaluation for lymphoma and urine VMA when there is concern for neuroblastoma.

• Pathology of the incised lymph node is helpful in ascertaining a definitive diagnosis, especially when malignancy needs to be excluded.

Imaging

• Chest x-ray is helpful in the evaluation of malignancies, tuberculosis, HIV, and sarcoidosis.

• Computed tomography (CT) of the neck can be attained for infections to differentiate lymphadenitis and cellulitis from suppuration and abscess formation.

• Ultrasound can also make this differentiation and can be a less expensive alternative to CT. The attainment and interpretation of ultrasound results can be significantly operator-dependent (Figure 33-8).

Differential Diagnosis

• Differential diagnosis of lymphadenopathy is extensive but can be differentiated into inflammatory versus malignant causes.

• The most common inflammatory causes are due to viral infections, which commonly cause nonspecific, reactive lymphadenopathy and infections with cytomegalovirus (CMV) or EBV or Varicella-zoster virus (VZV).

• The most common bacterial causes of adenopathy are streptococcal or staphylococcal upper respiratory infections, mycobacterial or atypical mycobacterial, cat scratch disease, and bacterial adenitis.

• Fungal infections, especially tinea capitis, can cause lymphadenopathy (Figure 33-9).

• Non-infectious inflammatory causes include Kawasaki disease (see Chapter 177, Kawasaki Disease), Kimura disease, histiocytosis, and PFAPA syndrome (see Chapter 176, Periodic Fever Syndromes).²

• The most common malignant causes include lymphoma, leukemia, rhabdomyosarcoma, neuroblastoma, and nasopharyngeal carcinoma.

Management

• Treatment in general is directed toward underlying etiology.

• Early biopsy should be considered when there is involvement of supraclavicular nodes, systemic symptoms, fixation or hard masses, abnormal chest x-ray findings, or rapid enlargement or increase in adenopathy in the absence of obvious infection.² SOR C

Nonpharmacological

• Observation and conservative management including rest, hydration, and pain control is reasonable in acute adenopathy from viral causes and with no concerning features in the history and physical exam.

• Reassurance is important to family members since the majority of cases of acute lymphadenopathy, especially in children, are due to transient, self-limited diseases, such as viral upper respiratory infections, that resolve within 4 to 6 weeks without sequelae.

Medications

• Treatment of viral lymphadenitis ranges from observation to anti-viral medication, depending on the type of virus, the severity of the symptoms, and the immune status of the host.

• Treatment of bacterial lymphadenitis often requires antibiotics, and sometimes surgical drainage.

• Subacute infections, including atypical mycobacterial infection, cat-scratch disease, protozoan and fungal infections, as well as sexually transmitted diseases, may be treated medically and occasionally surgically, depending on the infecting organism, the severity of the symptoms, and the immune status of the patient.

• Autoimmune disorders and malignancies are managed according to current treatment protocols specific for each disease.

Surgery

• Options include needle aspiration, incision and drainage, incision and curettage, and excision/excisional biopsy (Figure 33-10).

• Small unilocular abscesses can resolve with needle aspiration itself followed by antimicrobial/antifungal therapy based on culture results.

• Larger abscesses or abscesses associated with airway compromise, impending complications, or severe systemic illnesses should undergo incision and drainage.² SOR B

• Excision of nodes or excisional biopsies should be considered in cases of nontuberculous mycobacterial adenopathy due to incidence of sinus tracts and development of chronic drainage whenever there is concern for malignancy.^2,4 SOR B

Referral

• For head and neck lymphadenopathy, early consult to otolaryngology is important to determine need for surgical intervention and to aid in attaining cultures.

• If concern for malignancy is present, hematology/oncology consultation is important.

Prevention and Screening

• Avoiding sick contacts (including in childcare centers) may reduce the incidence of benign reactive lymphadenitis in children.

• Appropriately timed vaccinations can prevent childhood illnesses associated with lymphadenopathy such as rubella, rubeola, and varicella.

Prognosis

• Complications of poorly managed infectious causes of lymphadenopathy can result in progression of illness resulting in systemic toxicity, suppuration, vascular complications such as venous thrombosis, and/or airway compromise.

• Delay in diagnosis of malignancy can result in progression in stage and worsened prognosis.

Follow-Up

• The type of treatment used, whether surgical or medical, and response to treatment will determine the timing of follow-up and need for further testing.

Patient Education

• Patients (and parents) should be advised to notify their physician with increasing size and number of lymph nodes, development of constitutional symptoms in addition to lymphadenopathy, and with persistence of enlarged lymph nodes.

Patient Story

A newborn male, day of life 0, presented with respiratory distress requiring intubation. He was noted to have low set ears, micrognathia, and a cleft palate. Upon closer examination, he was also noted to have a right-sided complete aural atresia and the left canal is stenotic. His midface appeared hypoplastic and he was noted to have a cleft palate. A genetics consult was obtained and the patient was diagnosed with Treacher Collins syndrome (Figure 34-1). Surgical repair of palate was performed at 10 months of age, and a softband bone conduction device was provided in infancy for hearing habilitation. The family was counseled regarding ultimate options for reconstruction of microtia and aural atresia.

Introduction

Congenital anomalies in the head and neck are numerous and varied. In this chapter, we provide a general approach to the diagnosis and management of children with these anomalies and then outline an anatomic approach to considering these abnormalities using some illustrative photographs of those commonly encountered or unique entities.

Consensus terminology is critical for discussion. An anomaly is a structural or functional defect, which is present at the time of birth. A malformation is a major defect that is the result of incorrect morphogenesis. A sequence is a series of defects that occur in a nonrandom fashion. A single event then leads to a series of malformations. Pierre-Robin sequence is an example of a sequence. An association is encountered when there is a tendency of some malformations to occur together more commonly than would be expected by chance, but are not considered to be a part of an established malformation syndrome. An example is the CHARGE association, which includes coloboma, heart anomaly, choanal atresia, retarded growth, genital, or ear anomalies.¹

Diagnosis

Clinical Features

• Congenital anomalies in the head and neck are common and a thorough head and neck examination is recommended.

• An initial airway evaluation for signs of distress or obstruction is essential. This includes observation of retractions and desaturations, listening for stridor, stertor, as well as evaluation of the voice. Stridor is generally a higher pitched sound and can occur during inspiration, expiration, or both. Stertor sounds more like snoring and occurs on inspiration, and is more indicative of obstruction in the nasal cavity, nasopharynx, or oropharynx. A hoarse, quiet, or raspy cry may indicate vocal cord pathology such as cord immobility or mass.

• Noting abnormalities in the general appearance of the infant such as facial asymmetry, low set ears, or down-slanting palpebrae may help to identify syndromic pathology. Skin changes such as skin tags, sinuses, and vascular malformations should be noted.

• The ear exam should include not only evaluation of the pinnae, but also assessment of canal patency for atresia. Routine examination of the tympanic membrane and middle ear is also critical. A newborn hearing screen with consideration of both auditory brainstem responses and otoacoustic emissions testing should be discussed with an audiologist or neonatologist if appropriate.

• External nasal examination should include evaluation for pits or central hair, which could be indicative of a nasal dermoid. Anterior nasal rhinoscopy can be performed using an otoscope to assess for nasal mass or lesion. If there is suspicion for nasal obstruction, a 5 or 6 French catheter should be passed. If resistance is met, this may indicate intranasal obstruction. The need for nasal endoscopy can be determined by referral to a pediatric otolaryngologist.

• An oral exam should include visual inspection of the whole oral cavity and posterior oropharynx as well as bimanual palpation of the floor of mouth and assessment of the infant’s lip and palate.

• The neck should be evaluated for masses, pits, or draining sinuses.

• As several craniofacial syndromes are associated with ocular abnormalities, routine exam of the eyes should be performed and ophthalmology consultation obtained if needed.

• Any infant with suspected upper airway anomaly should be examined by a pediatric otolaryngologist. In the patient who is awake, a bedside flexible nasolaryngoscopy allows for a dynamic airway exam. If warranted, a complete airway evaluation in the operating room includes a direct laryngoscopy with rigid and/or flexible bronchoscopy. The need for such an exam depends on the clinical scenario and is a decision to be made by the consulting otolaryngologist.

Laboratory Data

• Various laboratory data and genetic testing may be obtained depending upon the identified anomaly. This is tailored to the patient and made in conjunction with neonatology, genetics, and other specialty team members.

Management

• The management of congenital abnormalities is specific to each pathologic process.

• A genetics consultation should be initiated if multiple anomalies are identified or if a syndrome is otherwise suspected.

• The appropriate consultations to an otolaryngologist, ophthalmologist, plastic surgeon, or other pediatric specialists will guide nonsurgical and surgical management.

• While cosmetic concerns may be most immediately apparent, functional anomalies related to airway, feeding, vision, and hearing should be prioritized.

Head and Neck Anomalies By Anatomic Site

The more common head and neck anomalies will be discussed by anatomic site. A tabular summary will include basic epidemiology, evaluation, and management.

Congenital Nasal Anomalies (Table 34-1; Figures 34-2 to 34-4)

• Embryology—At approximately 3 weeks of gestation, the nasal placodes develop as invaginations of neural crest cells from the frontal prominence into nasal pits. These deepen to eventually create medial and lateral nasal prominences. Posteriorly, the nasobuccal membrane forms to separate the nasal and oral cavity. Failure of this membrane to degenerate causes choanal atresia.^2–4

• The medial nasal prominence will fuse in the midline forming the columella, philtrum, and primary palate. The maxillary prominences fuse in the midline posteriorly creating the secondary palate (posterior to the incisive foramen) and to the medial nasal prominences anteriorly forming the upper lateral lip. Failure of all three fusions to occur (medial nasal prominence to maxillary prominences, left and right, and maxillary prominences in the midline) will create a bilateral complete cleft lip and palate.^2–4

• Between the superior aspect of the nasal bone and the inferior aspect of the frontal bone there is a transient fontanelle. A pyramidal shaped extension of dura extends inferiorly toward the osseocartilaginous junction of the nasal bridge. This is temporarily congruent with the epidermal elements of the nasal dorsum and protrudes through the skull base at the foramen cecum. Failure of these layers to separate can cause a variety of midline nasal masses such as dermoids and neurogenic nasal deformities.^3,5

Congenital Ear Anomalies (Table 34-2; Figures 34-5 and 34-6)

• Embryology—The otic placode is present at the third week of gestation. The auricle is derived from the six hillocks of His, from the first and second branchial arches, that are present by the sixth week of gestation. These form the tragus, antitragus, antihelix, helix, lobule, and the helical crus. The hillocks have fused by week 12. Cartilage formation begins in the 7^th week of gestation.⁶

Congenital Oral/Oropharyngeal Anomalies (Table 34-3; Figures 34-7 through 34-13)

• Embryology—The mandible is derived from Meckel’s cartilage, which is the lower portion of the first branchial arch. Development takes place from the 4th to 10th week of gestation. The tongue is actually derived from branchial arches 1 to 4 as well as occipital stomites (masses of mesoderm along sides of neural tube). The tongue originally forms in the nasal cavity and as the palatine shelves join in the midline, the tongue is pushed inferiorly into the oral cavity. See the preceding nasal/oral embryology for more detail. In the setting of Pierre Robin Sequence, it is hypothesized that relative macroglossia prevents the palatine shelves of the maxillary prominences from fusing, creating a midline cleft palate.¹²

Congenital Cervical Anomalies (Table 34-4; Figures 34-14 through 34-18)

• Embryology—The thyroid gland forms from a diverticulum arising between the anterior 2/3 and posterior 1/3 muscle tongue. This descends caudally, anterior to the hyoid, and fuses with fourth and fifth branchial pouches to form the thyroid.¹³ The branchial arches are responsible for much of the musculoskeletal and neural development of the head and neck. Branchial anomalies result from incomplete obliteration of the clefts and pouches, and are classified by the cleft or pouch of origin. The origin affects the location of associated fistulae and relationship to nerves, arteries, and muscles. This has clear relevance for surgical resection. Branchio-oto-renal syndrome is a classic example of a genetic cause for congenital branchial arch abnormalities.

• Branchial anomalies can present as cysts, sinuses, or fistulae. Cysts have no external opening, sinuses open to the skin, and fistulae have a skin opening and an opening into the pharynx.

Other Anomalies and Syndromes

• Cleft lip/palate—Orofacial clefting occurs in approximately 1/700 live births with a higher prevalence in Native Americans and Asians, and a lower prevalence in African Americans. It is the second most common birth deformity (second to club foot) and 2/3 of these children have other associated abnormalities.¹⁴ Cleft lip is associated with cleft palate in 68 to 86 percent of cases and a unilateral cleft is more common than bilateral.⁴ Management is best orchestrated in the context of a multidisciplinary Cleft-Craniofacial team (Figures 34-19 and 34-20).

• Vascular anomalies—These include vascular tumors such as hemangiomas as well as malformations such as capillary and venous malformations, arteriovenous malformations (AVM), and lymphatic malformations. Other than focal hemangiomas, they are best managed by a multidisciplinary vascular anomalies team, consisting of dermatology, plastic surgery, otolaryngology, radiology, and other specialists. A brief discussion follows for selected lesions.

  • Hemangiomas: These common benign neoplasms are composed of proliferating endothelial type cells, and affect the head and neck in 60 percent of cases. They typically develop after birth and have a characteristic proliferate phase, plateau phase, and subsequent involutional phase. They have varied presentations and treatment is individually tailored. If they have no complications (ulceration or bleeding) or a threat to function (vision, airway, cosmesis, etc.), they may be observed. First line medical therapy previously consisted of systemic corticosteroids, but the use of propranolol has supplanted this. Surgery has a role for aggressive proliferative or function threatening lesions, or after incomplete involution.¹⁵

  • Venous Malformations (VMs)—VMs are benign malformations made up of ectatic veins. They differ from hemangiomas, as they are present at birth, grow proportionally with the child, and are not proliferative lesions. MRI can help confirm diagnosis and determine extent of lesion. They are low-flow lesions that are isointense to muscle on T1-weighted images and enhance brightly on T2. Conservative management, injection sclerotherapy, and laser therapy are usually first line options, with surgery reserved for persistent symptomatic disease (Figure 34-21).¹⁶

  • Lymphatic Malformations (LMs, previously known as cystic hygroma or lymphangioma)—These are rare vascular anomalies, common in the head and neck, from aberrant formation of peripheral lymphatic vessels or fusion with venous structures, occurring in 1 to 4/10,000 births. They are categorized as macrocystic, microcystic, or combined lesions depending on the size of the fluid filled compartments. They present as asymptomatic masses or with functional difficulties such as dysphagia or airway difficulties. MRI is imaging modality of choice, typically with low signal intensity on T1-weighted images, high signal intensity with well demarcated margins on T2-weighted images. LMs may be identified on antenatal ultrasound and appropriate airway planning should be anticipated. LMs are difficult to treat. Medical therapy with antibiotics and anti-inflammatory may be used if they acutely worsen. Definitive treatment varies based on de Serres staging, affected site and type of lesion, and is individualized. Observation, surgery, and injection sclerotherapy are options for macrocystic lesions. These same options exist for microcystic lesions, which are more difficult to treat (Figures 34-22 and 34-23).¹⁷

• Syndromic associated anomalies—Congenital anomalies of the head and neck can be associated with numerous genetic abnormalities and syndromes (Figures 34-1 and 34-24). Table 34-5 lists some of those, which are more commonly encountered. Head and neck, other findings, and the causes are listed.