Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton

Insights into Imaging https://doi.org/10.1007/s13244-018-0623-4 REVIEW Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton Salvatore Stefanelli 1 & Pravin Mundada 1 & Anne-Laure Rougemont 2 & Vincent Lenoir 1 & Paolo Scolozzi 3 & Laura Merlini 1 & Minerva Becker 1 Received: 18 December 2017 / Revised: 26 February 2018 / Accepted: 19 March 2018 # The Author(s) 2018 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 pretherapeutic 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. Keywords Head and neck . Maxillofacial . Developmental lesions . CT . MRI Abbreviations ADC Apparent diffusion coefficient AVM Arterial vascular malformation CBCT Cone beam CT CEMRI Contrast-enhanced MRI * Salvatore Stefanelli 1 Division of Radiology, Department of Imaging and Medical Informatics, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland 2 Division of Clinical Pathology, Department of Genetic and Laboratory Medicine, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland 3 Clinic of Maxillo-facial Surgery, Department of Surgery, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland CISS CNS CSF CT DC DVM DWI FD FDG FLAIR H-E LM MPNST MRI NBCCS NDSC NF1 OKC Constructive interference steady state Central nervous system Cerebrospinal fluid Computed tomography Dermoid cyst Desmoplastic variant of medulloblastoma Diffusion-weighted imaging Fibrous dysplasia F18-Fluoro-deoxy-D-glucose Fluid attenuation inversion recovery Haematoxylin and eosin staining Lymphatic malformations Malignant peripheral nerve sheath tumour Magnetic resonance imaging Nevoid basal cell carcinoma syndrome Nasal dermoid sinus cyst Neurofibromatosis type 1 Odontogenic keratocyst Insights Imaging OPT PET-CT PNF TM TMax TMJ TP US VM VR VVM Orthopantomography Positron emission tomography computed tomography Plexiform neurofibroma Torus mandibularis Torus maxillaris Temporomandibular joint Torus palatinus Ultrasonography Vascular malformation Volume rendering Venous vascular malformation Introduction Masses and mass-like lesions related to various developmental and genetic conditions can affect the developing craniofacial skeleton. The majority of masses and mass-like conditions of developmental/genetic origin are benign. Some of these conditions, such as torus palatinus and torus mandibularis, require no treatment other than alleviation of parental anxiety. Other conditions affecting the developing craniofacial skeleton, such as fibrous dysplasia, ossifying fibroma, familial gigantiform cementoma, cemento-osseous dysplasia, hereditary multiple osteochondroma or plexiform neurofibroma, may cause functional impairments due to the proximity to important neurovascular structures, organs of special senses and developing dentition. Cosmetic deformities, due to the lesion itself or due to treatment-related asymmetric facial growth, may cause a significant psychosocial impact on the patient’s life. Management of these patients, therefore, often requires close interdisciplinary work-up, precise and often complex treatment planning strategies and post-treatment surveillance into adulthood. Radiologists, as part of an interdisciplinary team, play an important role in the management of these young patients. In addition, as these rare lesions may mimic neoplasms of the craniofacial skeleton and vice versa, it is imperative to be aware of their characteristic imaging features in order to avoid unnecessary biopsy and expensive follow-up examinations. To the best of our knowledge, a review of the imaging features of these rare masses and their impact on treatment has not been published in the English literature during the past 20 years. Most published articles on the subject are isolated case reports or small case series dealing with the clinical presentation and with patient management. This article attempts to provide a comprehensive radiological review of the most common developmental masses involving the craniofacial skeleton, along with their multimodality imaging features, clinical manifestations and the role of imaging in their pluridisciplinary management [1–5]. Imaging techniques The majority of masses and mass-like conditions of developmental/genetic origin are benign. Imaging narrows down the differential diagnosis and helps in planning patient management. Traditionally, ultrasonography (US) and conventional x-ray radiography have been the mainstays of imaging in paediatric lesions. US allows differentiation between solid and cystic lesions of the facial soft tissues and enables rapid assessment of the vascularisation and localisation of the extraosseous components. The US transducer types to be used should be adapted to the small parts investigated. High-frequency linear array transducers (> 8 MHz, often > 10 MHz) yield excellent spatial resolution, but at the expense of a shallower depth of penetration. US should be ideally coupled with a Doppler evaluation. Based on the Doppler flow waveform, differentiation between infantile haemangioma, a vascular tumour gradually involuting over the years, from low-flow (venous), lymphatic or high-flow (arteriovenous) vascular malformations is facilitated. However, US has a very limited role in the evaluation of the craniofacial skeleton itself. Imaging techniques using ionising radiation, including orthopantomography (OPT), computed tomography (CT) and cone beam CT (CBCT) warrant careful use in accordance with the ALARA (As L (...truncated)