Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton

Abstract

Although rare, masses and mass-like lesions of developmental and genetic origin may affect the paediatric craniofacial skeleton. They represent a major challenge in clinical practice because they can lead to functional impairment, facial deformation and disfigurement. The most common lesions include fibrous dysplasia, dermoid cysts, vascular malformations and plexiform neurofibromas. Less common lesions include torus mandibularis and torus palatinus, cherubism, nevoid basal cell carcinoma syndrome, meningoencephalocele and nasal sinus tract. This article provides a comprehensive approach for the evaluation of children with masses or mass-like lesions of developmental and genetic origin affecting the craniofacial skeleton. Typical findings are illustrated and the respective roles of computed tomography (CT), cone beam CT (CBCT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) sequences and ultrasonography (US) are discussed for the pre-therapeutic assessment, complex treatment planning and post-treatment surveillance. Key imaging findings and characteristic clinical manifestations are reviewed. Pitfalls of image interpretation are addressed and how to avoid them.Teaching points • Masses of developmental and genetic origin may severely impair the craniofacial skeleton. • Although rare, these lesions have characteristic imaging features. • CT, MRI and ultrasonography play a key role in their work-up. • Recognition of pivotal imaging pearls and diagnostic pitfalls avoids interpretation errors.

Newborn With a Sublingual Mass

“…7 Dermoid cysts result from ectoderm and mesoderm sequestration during the midline union of the embryonic first and second branchial arches. 8,9 Approximately 7% of dermoid cysts are found in the head and neck, primarily in the supraorbital region, followed by floor of mouth, nose, orbit, and cheek. 8 A true dermoid cyst has a stratified, keratinized epithelial lining with skin appendages and may have a "sack-of-marbles" appearance on magnetic resonance imaging.…”

“…8,9 Approximately 7% of dermoid cysts are found in the head and neck, primarily in the supraorbital region, followed by floor of mouth, nose, orbit, and cheek. 8 A true dermoid cyst has a stratified, keratinized epithelial lining with skin appendages and may have a "sack-of-marbles" appearance on magnetic resonance imaging. When such a lesion presents, fatty components, often collected in nodules, appear isointense on T1-weighted images and hypointense on T2-weighted images.…”

Torus palatinus in a 13-year-old Spanish girl

“…Although TP is clinically present around the age of 20 years, they are thought to be detectable during infancy too. TP is considered to be a slow-growing benign lesion that can take decades to grow into a noticeable size and patients generally do not report them as they are asymptomatic [1]. TP is frequently identified on CT scans, where it appears as a bone protuberance in a typical location with a density similar to that of compact bone.…”

“…This complementary exam is only needed in cases in which possible complications such as pathological fractures and necrosis must be diagnosed or for diverse dental planning. MRI is not an imaging method of choice to identify TP, nor is it used for diverse dental planning [1,2]. Prior population studies report a widely varying prevalence of TP with a range of 2-67% and suggest differences in prevalence among sexes and populations, occurring most frequently in females and individuals with Asian and Inuit ancestry [3].…”

“…Since the lesions are benign and usually asymptomatic treatment is not warranted. In case of discomfort, prosthetic treatment, or need for autogenous bone grafting, surgical removal can be performed [1,3].…”