Imaging Evaluation of Pediatric Parotid Gland Abnormalities

Abstract

Parotid gland lesions in children can be divided into benign or malignant. The age of the patient helps narrow the differential diagnosis, with vascular and congenital lesions being more frequent in the 1st year of life, while solid tumors are more frequent in older children. Inflammatory disease usually has rapid onset in comparison with that of neoplastic or congenital processes, which have more gradual clinical evolution. Currently, multiple imaging techniques are available to study the parotid region, such as US, CT, and MRI. However, it is still a challenge to distinguish nonmalignant lesions from malignant ones. US is the first-line diagnostic approach in children to characterize the morphology and vascularity of these lesions. CT in children may be indicated for evaluation of abscesses or sialolithiasis. MRI is the imaging modality of choice for investigating the nature of the lesion and its extent. In addition to complete and detailed clinical information, knowledge of parotid gland anatomy and characteristic radiologic features of parotid disorders is essential for optimal radiologic evaluation and avoiding unnecessary interventional diagnostic procedures or treatment. This article illustrates a variety of entities (congenital, inflammatory, vascular, neoplastic) that can occur in the parotid gland, highlighting the most frequent radiologic patterns of manifestation and correlating them with clinical, surgical, and pathologic findings. RSNA, 2018.

Imaging of parotid anomalies in infants and children

“…Imaging workup shows necrotic lymphadenitis: hypoechoic lymph node with peripheral hypervascularization on ultrasonography [ 22 ], and a hypodense lymph node with rim enhancement and surrounding soft tissue edematous swelling on CT (Fig. 6 ) [ 23 ]. These imaging features may mimic malignant disorders (metastasis, sarcoma or hemopathy) or other infectious, pyogenic or mycobacterial conditions.…”

“…Vascularization of the gland is a normal appearance, on Doppler color imaging [ 26 ]. According to the stage of the disease, early or late, the parotid gland is either enlarged or atrophic [ 23 ]. When a second imaging modality is needed, MR sialography can confirm the diagnosis.…”

“…Tumor enhancement is mild, more or less homogeneous, also depending on the tumor size. Generally, the apparent diffusion coefficient (ADC) is high in pleomorphic adenoma, as is it classically in benign tumors [ 23 , 25 ] (Fig. 14 b–d).…”

“…In the parotid gland, it arises from the facial nerve trunk or its branches. When it is solitary, the neurofibroma is generally isolated [ 23 ]. When it is plexiform or multiple, it may be associated with neurofibromatosis type 1 (von Recklinghausen disease).…”

Sialoblastoma and Hepatoblastoma in an Infant: A Case Report and Review of the Literature

“…In DWI, hemangioma typically exhibits no diffusion restriction. Centripetal contrast enhancement is the most specific imaging feature of hemangiomas (17,21,22).…”