a b s t r a c t

Background: Although ultrasound is regarded as the first choice imaging modality for evaluating a pediatric neck mass, neck computed tomography (CT) is necessary for urgent surgical conditions such as deep neck infections. Our aim was to evaluate the diagnostic effectiveness of and proper patient selection for neck CT as a method for the initial evaluation of pediatric neck masses in the emergency department.

Methods: We analyzed the medical records of 105 pediatric patients who visited the emergency department with neck mass whose initial imaging work-up was a neck CT and who visited the emergency department with a neck mass. The parameters investigated included the patient’s age, sex, symptom duration, Clinical impression, CT interpretation, final diagnosis, and treatment. The positive predictive value (PPV) for CT was calculated, and the parameters that correlated with an urgent surgical condition post-CT were evaluated. Results: The median age was 6.5 years (1 month to 12 years), and the male-to-female ratio was 2:1. The most common initial impression was acute cervical lymphadenopathy. A comparison of the final diagnosis and CT scan demonstrated that the overall PPV was 96.2%. If the initial impression was a deep neck infection, a salivary gland infection, or tonsillitis, the PPV for CT was 100%. Fever (N38.0?C) and severe tenderness were significant between patients with and without urgent surgical conditions on CT.

Conclusions: Computed tomography could be considered as the first Diagnostic modality when an urgent surgical condition such as a deep neck infection is highly suspected.

(C) 2014 The Authors. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/3.0/).

Introduction

Neck masses are common in children and are a frequent cause of visiting the emergency department. The most common etiologies include congenital lesions and their complications; lymphadenopathy; and vascular, inflammatory, and malignant lesions. Until recently, ultrasound (US) has been regarded as the first modality for investiga- tion, as it is readily available and does not involve ionizing radiation, which computed tomography (CT) has, and does not require the sedation of infants as often as magnetic resonance imaging [1].

Computed tomography can be used to determine the extent of a mass and better define its tissue characteristics and anatomy, especially with urgent surgical conditions. The usefulness of CT with a neck infection, especially pediatric deep neck infections, has been demonstrated in numerous prior studies [2]. In a study of 38 children

? Financial disclosure: None.

?? Conflict of interest: None.

* Corresponding author. Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital 100 Daehak-Ro Jongno-Gu, Seoul, Korea. Tel.: +82 2 2072 0215; fax: +82 2 745 2387.

E-mail address: [email protected] (J.H. Hah).

and adults with deep neck infections, CT was shown to have a sensitivity of 88% for diagnosing an abscess [3]. A similar study of 16 CT scans of deep and lateral neck abscesses demonstrated a sensitivity of 91% [4]. However, more than 90% of all pediatric neck masses will be inflammatory without an abscess. Moreover, self-limited viral infections mostly cause inflammation and lymph node hypertrophy, and children routinely experience idiopathic self-limiting episodes of lymph node enlargement, including lymph nodes of 2 to 3 cm in diameter. Therefore, considering radiation-related cancer risks related to the CT imaging of pediatric neck masses [5], CT would be better if used as a second-line method for evaluating a neck mass. However, patients with some conditions that necessitate immediate surgical exploration and urgent otolaryngology consultation may be candi- dates for an initial CT evaluation.

In clinical settings, CT is sometimes used as the first choice imaging modality for pediatric neck masses. At some institutions, a US technician may not be consistently available overnight or on weekends [6]. Consequently, less-experienced physicians in the emergency department might first order a CT scan for a small neck lesion that could result in omitting the evaluation by US, where the most of the pediatric neck mass can be differentially diagnosed without radiation. Herein, our aim was to evaluate the diagnostic

http://dx.doi.org/10.1016/j.ajem.2014.07.031

0735-6757/(C) 2014 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

1238 D.Y. Lee et al. / American Journal of Emergency Medicine 32 (2014) 1237-1240

effectiveness of and proper patient selection for neck CT as an initial evaluation method for pediatric neck masses in the emergency department.

Materials and methods

A retrospective chart review was performed of the medical records of pediatric patients who were younger than 15 years old who visited the emergency department of tertiary referral hospital between January 1, 2008, and December 31, 2012. Inclusion criteria were as follows: (1) patients presented with a neck mass or swelling;

(2) initial imaging work-up included a neck CT; (3) no previous history of inflammatory cervical disease, congenital neck mass, neck operation, or malignancy such as lymphoma; and (4) no previous history of an immune-compromising disease or medication. Because the routine evaluation of pediatric neck mass is the US in the emergency department, initial neck CT was performed by several reasons such as unavailable sonographer, order by inexperienced physicians, and suspicion for emergent surgical conditions.

Investigated parameters included the patient’s age, sex, symptom duration, initial impression, CT interpretation (location of neck mass, multiplicity, and neck mass characteristics), final diagnosis, and treatment. Final diagnosis is made mainly by pathologic and microbiological evaluation of excised or aspirated specimen, and some cases without any surgical specimen (ie, tonsillitis) reached to final diagnosis by response to medication. An indicators of Predictive performance, including sensitivity, specificity, and positive predictive value (PPV), were calculated for CT imaging for each final diagnosis. We categorized the patients into 2 groups based on their requirement for urgent surgical exploration such as incision/drainage: group 1, patients who required urgent surgical exploration (ie, deep neck infection); and group 2, patients who required no emergent surgical exploration (ie, acute nonsuppurative cervical lymphade- nopathy). Differences regarding patients’ symptoms and characteris-

tic of neck mass between the 2 groups were evaluated.

A statistical analysis was performed using the software package, SPSS for Windows, version 20.0 (SPSS Inc, Chicago, IL). A statistical difference between the 2 groups was evaluated using the independent t test for age and symptom onset and ?² test for the other categorical parameters. To adjust for the correlated variables in univariate analysis, a binary logistic regression analysis was used to identify the factors independently associated with urgent surgical condition (dichotomous data). A P b .05 was considered statistically significant.

Results

A total of 105 patients were included in our study. The median age was 6.5 years (1 month to 12 years), and the male-to-female ratio was 2:1. The mean symptom duration was 4.1 (+-2.5) days. Upon physical examination, the location of the neck mass was palpable unilaterally in 64 patients (60.9%), bilaterally in 26 patients (24.8%), and midline in 15 patients (14.3%). A single mass was palpable in 62 patients (59.0%), whereas multiple masses were palpable in 43 patients (41.0%). The most common clinical impression was acute cervical lymphadenopathy (30.5%), followed by a deep neck infection or an abscess (24.8%), a congenital mass such as a brachial cleft cyst (20.0%), a salivary gland infection (6.7%) or stone (4.8%), other benign mass (eg, lipoma) (3.8%), and malignancy (1.9%) (Table 1). Among 105 patients, 33 patients (31.4%) subsequently underwent ultrasono- graphic evaluation for further evaluation (9, 18, 4, and 2 patients for initial impression of cervical lymphadenopathy, congenital mass, other benign mass, and malignancy, respectively) (Fig. 2). The result of US in our study showed a significant correlation with CT scan (r = 0.316, P b .012).

Initial clinical impression and CT interpretation were well

correlated for benign mass (100%) and congenital mass (81.0%) and

Table 1

Demographic data, characteristics of neck mass on physical examination, and clinical impression

Total patients 105

Median age (range) 6.5 (1 mo to 12 y)

Sex (M:F) 2:1 (70:35)

Mean symptom duration 4.1 (+-2.5) d

Physical examination Location of mass

Unilateral 64 (60.9%)

Bilateral 26 (24.8%)

Midline 15 (14.3%)

Multiplicity

Single 62 (59.0%)

Multiple 43 (41.0%)

Clinical impression

Cervical lymphadenopathy 32 (30.5%)

Deep neck infection, neck abscess 26 (24.8%)

Congenital mass 21 (20.0%)

Salivary gland infection 7 (6.7%)

Salivary gland stone 5 (4.8%)

Other benign mass 4 (3.8%)

Malignancy 2 (1.9%)

No description 8 (7.6%)

Final diagnosis

Cervical lymphadenopathy 49 (46.7%)

Deep neck infection, neck abscess 20 (19.0%)

Congenital mass 3 (2.9%)

Salivary gland infection/stone 15 (14.3%)

Other infection 12 (11.4%)

Malignancy 1 (1.0%)

Others 5 (4.8%)

Abbreviation: M:F, male-to-female ratio.

moderately correlated for a deep neck infection or an abscess (77.8%) and acute cervical lymphadenopathy (71.4%). As for the clinical impression of a salivary gland infection or stone and malignancy, the initial impression and CT interpretation were poorly correlated (57.1% and 0%, respectively). In general, sensitivity, specificity, and PPV of CT scan for final diagnosis were 71.4%, 91.4%, and 96.2%, respectively. Positive predictive value showed 100% in case of deep neck infection and salivary gland stone, where the final diagnosis is made by operation; and salivary gland infection and tonsillitis, where the final diagnosis is made by CT imaging and response to medication (83.5% and 100% of sensitivity and specificity). For CT interpretation, cervical

Fig. 1. Positive predictive value of CT for final diagnosis.

D.Y. Lee et al. / American Journal of Emergency Medicine 32 (2014) 1237-1240 1239

Fig. 2. Diagnostic flow sheet of 20 patients who need urgent surgical exploration.

lymphadenopathy and a congenital mass had a PPV of 94.6% and 93.8%, respectively (Fig. 1).

Table 2 shows the differences between groups 1 and 2. A fever of more than 38.0?C and severe tenderness demonstrated a significant difference between the 2 groups, whereas age, sex, symptom onset, swelling, mass location, laterality, and multiplicity showed no difference. Binary logistic regression analysis, which was used to adjust for fever (as a continuous variable) and tenderness (as a categorical variable), showed that factors associated with urgent surgical conditions were fever of more than 38.0?C (odds ratio, 6.609; 95% confidence interval, 1.046-41.867; P = .043).

Discussion

This study showed that neck CT can be used as an initial evaluation method for those patients whose physicians believe that their patients have a deep neck infection or an abscess accompanied by a high fever and severe tenderness during an initial examination. In terms of urgent surgical exploration, our institute routinely performs a neck CT

Table 2

Difference between group 1 and group 2

		Group 1	Group 2	P
Age (y)		>6.7	>6.2	.301
Sex	M	>13	>31	.477
Symptom duration (d)	F 4.0 (+-2.1)	>8 >4.2 (+-2.6)	>16 >0.685
Swelling Fever	+ - +	>14 >7 >14	>21 >26 >15	.078 .008
	-	>7	>32
Tenderness Location of mass	+ - Lateral neck	>14 >7 >12	>14 >33 >31	.005 .457
Laterality	Parotid area Submandibular area Midline Unilateral	>4 >5 >0 >17	>4 >12 >2 >29	.247
	Bilateral	>4	>16
Multiplicity	+ -	>8 >13	>24 >23	.234

Abbreviations: M, male; F, female.

Group 1, patients who need surgical exploration (eg, deep neck infection); group 2, patients who need no surgical exploration (eg, acute nonsuppurative cervical lymphadenopathy).

before operating on a deep neck infection or an abscess because CT imaging of a lesion and the surrounding anatomy could help while performing appropriate and safe drainage, without injury to vital neck structures. In this clinical study, for pediatric patients who have a high probability of a deep neck infection requiring incision and drainage, using CT imaging without a US evaluation to determine a fast and accurate diagnosis may help in developing a treatment plan quickly, thereby decreasing the probability of worsening of disease.

During routine evaluation of pediatric neck masses, US has been regarded as the first choice, although there have been reports regarding its limitation in evaluating midline neck masses [7,8]. Ultrasound has demonstrated great diagnostic performance in assessing thyroid masses, branchial cysts, and parotid lesions [9]. Moreover, for the head, the reliability of high resolution US for the distinction between a collection of purulent material and swelling without purulence was reported to be high, showing a sensitivity and specificity of 96% and 82%, respectively [7]. Despite this high diagnostic performance, drawback to the US is that US is examiner dependent. This makes the interpretation highly subjective and sometimes makes US unavailable if an examiner is not available. And for knowing surgical anatomy before the operation, we think that the data in neck CT are before the US due to lack of examiner dependency.

In terms of diagnostic performance of deep neck infections, there have been some evaluations regarding US and CT in medical literature. Although a pediatric study showed a relatively low sensitivity for US, recent studies reported the comparable diagnostic performance of US with CT scan [10]. These were promising results, but the application of US to pediatric neck abscesses may be limited by the aforementioned disadvantages. Moreover, with CT, physicians were able to more accurately diagnose an abscess located in the deep neck and thus provide more reliable information to surgeons.

In our study, the overall PPV for CT was 96.2%. As Fig. 1 shows, the PPV was 100% for a deep neck infection, a salivary gland infection, and tonsillitis. Although the correlation between the clinical impression and CT interpretation was not high in our study, a moderate correlation was observed regarding a deep neck infection and an abscess (77.8%). Furthermore, among patients who had a high fever and severe tenderness, CT revealed more cases that required urgent surgical exploration than those without high fever and tenderness. When a pediatric patient with a neck mass visits the emergency department and the clinical impression is a deep neck infection with a high fever and tenderness, there may be high probability of an urgent surgical condition that could be detected by CT. Subsequently, in those cases, CT may be the first choice for evaluating the pediatric neck mass.

1240 D.Y. Lee et al. / American Journal of Emergency Medicine 32 (2014) 1237-1240

Computed tomography has a disadvantage in terms of radiation, and there are many concerns regarding the negative Long-term effects of radiation from CT imaging. Computed tomography-related X-ray doses are large enough that statistically significant epidemiological evidence indicates a small increase in lifetime attributable risk of cancer incidence, ranging from 0.02% for 80-year-old men to nearly 1% for 20-year-old women [11]. On average, risks are 0.07% larger for children than adults. The cumulative radiation exposure for children younger than 15 years from having 2 to 3 head CTs may triple the risk of brain cancer [12]. Because of this limitation, CT must be carefully used in pediatric patients.

There were several limitations in our study. First, this study was performed as a retrospective chart review. This study was not a well- organized prospective study, so there could be missing data or an incorrect medical record. Second, there might be a selection bias, where the some portion of our study group is included because of improper CT order.

We are in absolute agreement that US should be the first recommended modality for evaluating pediatric neck masses. However, our results suggest that CT could be the first choice modality for both the evaluation and determination of a treatment plan for pediatric patients with a highly suspicious deep neck infection. A fast and accurate diagnosis followed by rapid referral to an head and neck surgeon could help more quickly ameliorate the patient’s status, thereby decreasing the incidence of actual malpractice cases caused by just waiting for a US.

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