2017 Sec 1 Green Book

Reprinted by permission of J Neuroimaging. 2016; 26(6):562-580.

Lumps and Bumps of the Neck in Children—Neuroimaging of Congenital and Acquired Lesions Marjolein H.G. Dremmen, Aylin Tekes, Samantha Mueller, Donna Seyfert, David E. Tunkel, Thierry A.G.M. Huisman From the Division of Pediatric Radiology and Pediatric Neuroradiology, Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD (MHGD, AT, SM, DS, TAGMH); Division of Pediatric Radiology, Department of Radiology, Erasmus MC – University Medical Center Rotterdam, Rotterdam, The Netherlands (MHGD); and Division of Pediatric Otolaryngology, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD (DET). A B S T R A C T Neck masses present as palpable lumps and bumps in children with acquired lesions more common than congenital ones. Assessment of the anatomical site of origin, signal, and contrast enhancement characteristics may help define the etiology of the lesions, eg, developmental, inflammatory, vascular, or neoplastic. The age of the patient along with detailed clinical history and physical exam findings are important element to narrow down the differential diagnosis. The correct final diagnosis is essential to guide treatment as well as the urgency of intervention. The objective of this review is to define the characteristic location, classic and differentiating imaging features of the most frequent congenital and acquired cervical lumps and bumps in the pediatric population.

Keywords: Congenital, acquired, neck lesions, children, imaging.

Acceptance: Received April 1, 2016. Accepted for publication June 18, 2016. Correspondence : Address correspondence to Marjolein H.G. Dremmen, Department of Radiology, Erasmus MC – University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands. E-mail: m.dremmen@erasmusmc.nl Acknowledgements and Disclosure : None.

J Neuroimaging 2016;00:1-19. DOI: 10.1111/jon.12376

Introduction Congenital masses (lumps and bumps) of the neck are by defi- nition present at birth. Despite the congenital origin of this type of lesions, some of these may not be clinically present until later in life. The etiology of congenital neck masses varies from de- velopmental anomalies to vascular, inflammatory, and tumoral lesions. 1 Many of the neck masses seen in children are acquired le- sions. These acquired lumps are most often benign, however, rarely can be malignant in children. The etiology is inflamma- tory, vascular, neoplastic, or of traumatic origin. 1 Mass lesions of the neck are often identified as bumps on physical examination. Imaging plays an essential role in the characterization and final diagnosis of the various entities. A systematic imaging approach to masses of the neck helps to narrow down the differential diagnosis. This approach includes determining the primary site of origin, involvement of, and extension across the various anatomic spaces of the neck, to evaluate the normal contents of the involved anatomic space and to assess the characteristic imaging features of the lesion. The age of the patient and the clinical presentation are also important factors and often characteristic for the type of lesion, and should consequently be taken into account during the in- terpretation of the imaging studies. The correct final diagnosis is essential to determine the proper treatment strategy. Ultrasonography (US) and magnetic resonance (MR) imag- ing are the primary imaging modalities of choice for many congenital neck lesions in the pediatric population. US offers a high-resolution image quality, is noninvasive, is readily available, and does not require sedation. Furthermore,

the real-time character of US examinations allows for the eval- uation of mobility and compressibility of the mass or changes in the internal structure of the lesion during, eg, respiration and swallowing. The additional use of Doppler US contributes in the assessment of the degree of vascularity/perfusion of the lesion and analysis of the spectral blood flow waveforms is valuable in differentiating several types of vascular anomalies. Anatomical MR imaging renders excellent soft-tissue con- trast, optimal visualization and delineation of involved or dis- placed anatomic spaces, vascular anatomy and neural elements, and more detailed internal tissue characteristics of the lesion. Advanced MR imaging techniques, like diffusion-weighted imaging (DWI) or susceptibility-weighted imaging (SWI), may provide additional valuable information on intralesional fea- tures, thus facilitating more specific diagnoses. 1–6 Multiphasic dynamic contrast–enhancedMR angiography (cMRA) is a non- invasive MRI technique used to determine the hemodynamics of the lesion, thereby providing valuable clues for the diagnoses. For vascular anomalies in particular, the time-resolved dynamic cMRA technique using a blood-pool contrast agent (eg, gadofos- veset trisodium) provides rapid acquisition combined with de- tailed temporal information of lesion hemodynamics and flow characteristics. 7,8 MRI has, however, the disadvantage of longer data acquisition times, and may require sedation for use in chil- dren. However, currently available fast sequence MR imaging techniques provide satisfactory assessment of the abnormality in a significant number of cases, thereby eliminating the need for sedation. The use of CT should be limited in children because of the potential long-term risks of ionizing radiation in this vulnerable

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