Head and Neck Masses in Children



Head and Neck Masses in Children


Cuneyt M. Alper

Jacob G. Robison



Primary care physicians commonly encounter children presenting with head and neck masses. Unlike adults in whom a neck mass is considered malignant unless proven otherwise, most pediatric neck masses are benign (1, 2). Most generalists are comfortable in treating and following acute inflammatory masses that appear to be benign lymph nodes. However, the vast majority of cases that do not fit this description get referred to a specialist. Although most head and neck masses are benign, they commonly present a diagnostic and therapeutic dilemma to the specialist.

Congenital, developmental, and inflammatory lesions make up most of the masses in the head and neck region. Neoplastic processes comprise 10% to 15% of head and neck masses in children. A retrospective review of 445 children with neck masses revealed that 55% of the masses were congenital, 27% were inflammatory, 5% were noninflammatory benign masses, 3% were benign neoplasms, and 11% were malignancies. In another series of 239 children who underwent cervical lymph node biopsy for nodal enlargement, 49% had idiopathic lymphoid hyperplasia, 37% had infectious lymphoid hyperplasia, and 13% had neoplasms (3). Although malignant neoplasms are not common, cancer ranks second to trauma as a cause of childhood mortality. About 5% to 10% of malignancies originate in, and 25% eventually involve, the head and neck, leading to enhanced concerns of parents and the primary care physicians resulting in early, and sometimes extensive, diagnostic workup and intervention (4). The need for surgical management of the more prevalent congenital masses and benign neoplasms also requires prompt and thorough diagnostic evaluation. Moreover, a number of congenital masses presenting for the first time with an inflammatory exacerbation may enhance the diagnostic and therapeutic challenge.

A practical approach to head and neck masses in children aims to differentiate congenital, inflammatory, and neoplastic etiologies based on location of the mass (Table 105.1). This chapter addresses general approach and differential diagnosis of the head and neck masses in children and covers inflammatory and neoplastic masses. Please refer to Chapter 106 for congenital neck masses and cysts, Chapter 104 for congenital vascular lesions, Chapter 98 for salivary gland disease in children, and Chapter 96 for congenital anomalies of the nose. Coverage of neoplastic pathologies is limited to those that are relatively more prevalent in childhood. Please refer to relevant chapters for the head and neck neoplasms that are rarely seen in the pediatric population.


ASSESSMENT



Laboratory Testing

Assessment of head and neck masses in children may include laboratory evaluation. Laboratory tests are seldom required as part of the workup for acute cervical lymphadenitis. Leukocyte count and markers of inflammation (C-reactive protein and erythrocyte sedimentation rate) are usually abnormal but nonspecific and do not assist in the diagnosis. However, for subacute, chronic, and generalized lymphadenopathy, laboratory evaluation plays a crucial role, and a complete blood count (CBC) with differential should routinely be performed in such conditions. In a more severe acute inflammatory condition such as a neck abscess, a high white blood cell count with higher lymphocytes is expected. Repeated CBC may be utilized to assess the response to the therapy. Atypical lymphocytes should raise the suspicion for infectious mononucleosis, test and heterophile antibody titers (Monospot test) may be used for confirmation.

Serologic tests for Bartonella henselae, syphilis, toxoplasmosis, cytomegalovirus (CMV), Epstein-Barr virus (EBV), tularemia, brucellosis, histoplasmosis, and coccidiodomycosis may suggest an infectious agent. Cervical lymphadenitis that is suspicious for either tuberculous or atypical mycobacterial infection should receive a purified protein derivative (PPD) testing. A positive intradermal tuberculin skin test is consistent with an infection due to Mycobacterium tuberculosis, but a negative test does not rule it out and will often manifest as a lesser reaction or negative reaction in nontuberculous mycobacterial infections (6). Any material that has been aspirated or collected due to fluctuance should be sent for culture and sensitivity. If history and physical are consistent with possible anaerobic or fungal infections, specific cultures need to be specified.

Neoplastic processes in head and neck may manifest themselves by an abnormal CBC and differential. Blood tests to help identify the cause, or the dissemination, of a malignant process are necessary, such as HIV test, chemistry panel, and a liver panel (4, 12). Alkaline phosphatase levels can help determine bone metastasis. Blood urea nitrogen, creatinine, lactate dehydrogenase, and uric acid are adjunct to the workup of lymphomas and other malignancies (13). Cerebrospinal fluid analysis is useful in the workup of central nervous system involvement in malignancies such as lymphoma.


Imaging

Diagnostic radiology is useful for not only narrowing the differential diagnosis of a neck mass but in order to help define the extent of the lesion and assist in preoperative planning. Common modalities include plain radiographs, ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). Other modalities such as positron emission tomography (PET) and radionuclide scans are also available, but are not widely used, particularly
with regard to inflammatory lesions, and therefore are not be discussed in this chapter.


Plain Radiographs

Radiographic studies are usually not necessary for evaluation of recent onset of masses that appear to be inflammatory. However, persistent or progressively enlarging adenopathy warrants a chest x-ray. A plain chest x-ray may detect pulmonary or mediastinal lesions as a source for cervical or supraclavicular adenopathy (14). Plain radiographs have been supplanted by the use of other more advanced imaging techniques in many situations. Currently, the main use of plain radiographs is for evaluation of the chest for the presence of lymphadenopathy or other pulmonology pathology, as well as soft tissue lateral neck radiographs to assess the airway and prevertebral soft tissue thickening. Initial workup for children with a potential cervical neoplasm should include PA and lateral chest radiograph. This may reveal mediastinal lymph node enlargement as the underlying cause of the airway obstruction or superior vena cava syndrome.


Ultrasound

Ultrasonography has some important advantages for use in the pediatric population; it does not involve ionizing radiation and is readily available (14). Ultrasound is often considered the first-line diagnostic imaging study by many centers (6, 15, 16). Ultrasound can easily distinguish solid from cystic lesions. Ultrasound is helpful in evaluating the thyroid and parotid lesions and may help diagnosing confusing congenital lesions (14). High-resolution ultrasound is able to assess nodal morphology and internal architecture as well as characterize the echogenic patterns of a mass, classifying them as cystic, solid, or complex in nature. Doppler ultrasound may be used to assess the presence of perfusion and its distribution as well as obtain measures of vascular resistance. Advantages of ultrasound are that it is noninvasive, avoids ionizing radiation, is portable and inexpensive, and can be performed without sedation in most patients. Drawbacks include difficulty to interpret, subject to skill level of operator, may not be able to visualize deeper lesions, and lack of anatomic information for surgical planning (17, 18, 19). High-frequency transducers are utilized to evaluate the lymph nodes in the neck as they provide better detail. A normal node as evaluated by ultrasound is a well-defined, elliptical structure with a hypoechoic halo and central sharp linear hyperechoic fatty hilum containing a single vessel (15). Power Doppler imaging of the vascularity of nodes can be useful in differentiating benign from malignant processes. This, however, requires the patient’s cooperation, which is sometimes difficult to achieve in young children. Sonographically, neurogenic tumors are elliptical or round hypoechoic solid masses posterior to the carotid sheath vessels in a paraspinal location, with or without intraspinal extension and with or without calcifications (16). Ultrasound does not have a high specificity in distinguishing benign from malignant nodes, and there is significant feature overlap. The features, when combined, that increase the suspicion of malignancy include round shape, absent or eccentric hilum, irregular borders, cystic necrosis, and chaotic capsular blood flow pattern (15). On ultrasound of lymphoma, the enlarged hypoechoic nodes show sharp borders with an absent or eccentric echogenic hilum and a tendency to form masses (20). In Hodgkin lymphoma and non-Hodgkin lymphoma, the affected lymph nodes tend to be round, hypoechoic, and without an echogenic hilum and are likely to demonstrate intranodal reticulation (16). Sonographically, most thyroid cancers are hypoechoic, and the tumor may be irregular and ill defined or smooth and well delineated. A sonolucent rim or halo may completely or partially surround the mass.


Computerized Tomography

Contrast-enhanced CT is the standard of imaging for rapid, accurate diagnosis of an acute deep neck abscesses. In a survey of pediatric otolaryngologist, CT scan was the imaging modality of choice for the evaluation of children with suspected deep neck infections (21). CT is able to differentiate between cellulitis and abscess and is also able to assess the location of the abscess in relation to important anatomical structures, helping to provide a surgical road map (17, 22). However, differentiation between phlegmon and abscess is sometimes not easy, and without the addition of intravenous contrast, it is impossible (23). Workup of a neck mass with possible neoplastic characteristics should include CT with contrast of the neck (24). On CT scan, lymph nodes are noted to have homogeneous soft tissue attenuation and present as elongated structures with well-defined, sharp margins with preserved adjacent fat planes and the occasional fatty hilum. However, the internal architecture of nodes is, for the most part, beyond the limits of CT evaluation (15). The CT scan is valuable in differentiating between cystic and solid lesions, establishing the location and exact size of the lesion, identifying other nonpalpable masses, determining the relationship of the mass with the surrounding tissues, assessing bony erosion or remodeling of the bone, and assessing the vascularity within the mass when the study is done with contrast. The high spatial resolution for high-contrast structures makes CT the imaging modality of choice for osseous and fibroosseous lesions in the head and neck (25). On CT, teratomas appear heterogenous, sharply circumscribed, with solid and cystic areas with variable enhancement of the solid component (26). Staging for a number of pediatric malignancies, such as lymphoma, requires CT of the head and neck as well as mediastinum. An abdominal CT scan is used to assess the involvement of the spleen liver and retroperitoneal lymph nodes. On a CT scan, nasopharyngeal carcinoma (NPC) shows a large enhancing mass filling the nasopharyngeal airway (26). CT scan does expose the patient to low doses of radiation, but it is faster than an MRI and, therefore, usually does not require sedation.



Magnetic Resonance Imaging

MRI has the advantage of exquisite sensitivity for soft tissue imaging with excellent anatomic detail. Some studies have shown it to be more successful than CT in distinguishing cellulitis or phlegmon from a true abscess collection; however, CT still remains the standard imaging technique for the evaluation of the acute neck abscess (25, 27). Advantages of MRI include the increased sensitivity of soft tissues, ability to provide multiplanar images, and the lack of radiation exposure. Lymph nodes are best seen on fluid-sensitive sequences (T2 or STIR) because they are isointense to muscle on T1 weighting (15). For assessing possible neoplastic masses, MRI provides much greater soft tissue detail and better vascular delineation. Disadvantages of MRI are the need for expensive imaging machinery and obtaining the scan often requires sedation secondary to the longer image capture times necessary. For osseous lesions, MRI can help assess the effect of an osseous lesion on the surrounding structures but should not be seen as a substitute for the CT scan (25). Neurofibromas and schwannomas are heterogenous, isointense to muscle on T1-weighted images, irregularly hyperintense on T1-weighted images, and enhance variably after gadolinium administration. T2-weighted images and fat suppression post-gadolinium-enhanced T1-weighted images are also very helpful (26). MRI has a distinct advantage over CT in evaluating for intracranial extension of tumor. Direct coronal imaging with fat suppression best demonstrates skull base involvement (26). Perfusion MRI is a noninvasive promising method that can be used for differentiation of malignant from benign cervical lymph nodes, and it helps in the characterization of malignant cervical lymphadenopathy (28).


Other

In specific clinical circumstances, radionuclide scans, PET scans, or angiographic scans may be useful. Workup of malignant disease includes searching for distant metastasis. Whole body bone scans are often used in metastatic workup such as for neuroblastoma. If alkaline phosphatase levels are elevated or there is bone pain, bone scans should be done. Gallium scanning is sensitive for identifying the sites of involvement. Recently, fluorodeoxyglucose positron emission tomography has been shown to be superior to the gallium scanning and has become the recommended procedure (29). Bone marrow core biopsies and aspirates are also part of the workup of staging in some malignant tumors such as lymphoma.



INFLAMMATORY MASSES

Inflammatory cervical lymphadenopathy is the most common pediatric neck mass (6). The inflammatory node is usually the result of a recent viral or bacterial infection but may be due to noninfectious etiologies as well. It has been reported that palpable cervical lymphadenopathy occurs with a prevalence of 28% to 55% in otherwise normal infants and children (5). Infectious etiologies for inflammatory head and neck masses in children are listed in Table 105.2.


Infectious Etiologies

Benign cervical lymph node hypertrophy is the most common cause of pediatric neck masses. Clinically palpable cervical lymphadenopathy occurs with a reported prevalence of 28% to 55% in otherwise normal children (5). Children may normally have less than 1-cm palpable lymph nodes. It is not uncommon that children develop idiopathic self-limiting 2- to 3-cm lymph node enlargement. Infectious etiologies are the most common cause of inflammatory cervical lymphadenopathy. Acute bilateral cervical lymphadenopathy is usually caused by viral respiratory tract infections or streptococcal pharyngitis, whereas unilateral cervical lymphadenitis is caused by streptococcal or staphylococcal infection in 40% to 80% of cases (34). Subacute or chronic lymphadenitis may be caused by mycobacterial infections, cat-scratch disease, and fungal,
parasitic, or opportunistic infections. Additionally, congenital neck masses may also present with an acute infection of the congenital mass.








TABLE 105.2 INFECTIOUS ETIOLOGIES FOR INFLAMMATORY HEAD AND NECK MASSES IN CHILDREN







  1. Acute viral lymphadenitis




    1. Common viruses




      1. Rhinovirus



      2. Parainfluenza virus



      3. Influenza virus



      4. Respiratory syncytial virus



      5. Cytomegalovirus



      6. Epstein-Barr virus



      7. Coronavirus



      8. Adenovirus



      9. Reovirus



    2. Rare viruses




      1. Mumps



      2. Measles



      3. Rubella



      4. Herpes simplex



      5. Human herpes simplex 6 (roseola)



      6. Coxsackie viruses



  2. Acute bacterial lymphadenitis




    1. Common bacteria




      1. Gram-positive bacteria




        1. Staphylococcus aureus



        2. Group A beta-hemolytic Streptococcus (S. pyogenes)



    2. Less common organisms




      1. Anaerobic bacteria




        1. Bacteroides sp.



        2. Peptococcus sp.



        3. Peptostreptococcus sp.



        4. Propionibacterium acnes



        5. Fusobacterium nucleatum



        6. Eikenella corrodens



        7. Prevotella sp.



      2. Gram-negative bacteria




        1. Francisella tularensis



        2. Pasteurella multocida



        3. Yersinia pestis



        4. Haemophilus influenzae



        5. Klebsiella sp.



        6. Serratia marcescens



        7. Moraxella catarrhalis



  3. Mycobacterial lymphadenitis




    1. Mycobacterium tuberculosis



    2. Nontuberculous mycobacteria



  4. Cat-scratch disease




    1. Bartonella henselae



  5. Fungal, parasitic, and opportunistic infections




    1. Histoplasma capsulatum



    2. Blastomyces dermatitidis



    3. Coccidioides immitis



    4. Toxoplasma gondii



    5. Nocardia sp.



Acute Viral Lymphadenitis

Many cases of bilateral cervical adenitis are caused by upper respiratory tract infections of viral etiology, including rhinovirus, parainfluenza virus, respiratory syncytial virus, CMV, EBV, coronavirus, adenovirus, and reovirus. Less common viral agents include mumps, measles, rubella, herpes simplex, human herpes simplex 6 (roseola), and coxsackie viruses (6, 35). Involved nodes are usually multiple, relatively small, and without warmth or erythema of the overlying skin. Acute bilateral or diffuse cervical lymphadenopathy is often the result of a recent viral infection and is usually a self-limited process (14). Viral-induced adenopathy rarely suppurates and generally resolves spontaneously over a short period of time (6). Acute viral lymphadenitis is variably associated with fever, conjunctivitis, pharyngitis, and other upper respiratory tract symptoms. Rashes and hepatosplenomegaly may also be present, particularly when CMV is the causative organism. These infections rarely require additional diagnostic testing or specific therapy. Treatment is directed at symptom relief and specific antiviral therapy is seldom indicated except in the rare patient with severe respiratory tract or hepatic involvement, or in the immunocompromised patient (6).


Acute Bacterial Lymphadenitis

Bacterial etiologies of cervical lymphadenopathy tend to be unilateral in nature. While the source of the initial infection may raise the suspicion for specific bacterial organisms, S. aureus and group A beta-hemolytic Streptococcus (Streptococcus pyogenes) are the most frequently isolated bacterial organisms from all cervical sites as a whole (36, 37, 38, 39). Bacterial-induced adenopathy tends to produce larger (greater than 2 to 3 cm), solitary, tender, unilateral lymph nodes that rapidly enlarge. Suppurative adenitis indicates an infected lymph node that has undergone liquefaction necrosis. Fluctuance develops in about 25% of patients with acute bacterial adenitis (6, 14). Common symptoms include fever, malaise, poor feeding, irritability, and swelling over the infected area with overlying skin erythema.

Over the past 10 to 15 years, there has been a sharp increase in the number of methicillin-resistant Staphylococcus aureus (MRSA) cases that have been reported. Reports from different hospitals/geographical areas indicate a 6% to 65% (22, 39, 40, 41, 42, 43) increase in incidence with time, and reports of resistance to other antibiotics have varied. With this trend noted, selection of an appropriate antibiotic for treatment needs to address the local incidence and antibiotic susceptibility of the common offending organisms. Usually antibiotics that are beta-lactamase stable or those that inhibit beta-lactamase are most desirable. The combination ampicillin-sulbactam has been used with good success in multiple studies and has activity against gram-positive, gram-negative, and anaerobic bacteria (44, 45, 46). When the patient has improved sufficiently to change from intravenous to oral therapy, the oral form of ampicillin-sulbactam, the prodrug sultamicillin, as well as amoxicillin-clavulanate are appropriate agents. Other good choices include cefuroxime axetil, cefprozil, and clindamycin. If there is suspicion for MRSA, recent studies have shown the majority of the community-acquired MRSA is still sensitive to clindamycin and Bactrim (22, 43). Anaerobic bacteria may be found in older children with dental caries or periodontal disease. The most commonly isolated anaerobic bacteria are Bacteroides sp., Peptococcus sp., Peptostreptococcus sp., Propionibacterium acnes, Fusobacterium nucleatum, Eikenella corrodens, and Prevotella sp. (6, 47).

Other more rare bacterial isolates include gram-negative bacilli such as Francisella tularensis, Pasteurella multocida, Yersinia pestis, Haemophilus influenzae, Klebsiella sp., Serratia marcescens, and Moraxella catarrhalis (6

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May 24, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Head and Neck Masses in Children
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