From: Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton
 | US | RX | CT/CBCT | MRI | FDG PET | Differential diagnosis |
---|---|---|---|---|---|---|
Fibrous dysplasia (FD) | (Not indicated) | Expanded, thickened bone with ground-glass density Occasionally areas of sclerosis or lucency | Expansile bone lesion in the medullary space with variable attenuation: sclerotic FD (ground-glass density), pagetoid FD (mixed radiopacity and radiolucency), cystic FD (centrally lucent lesions with thinned but sclerotic borders) | Low signal on T1 in ossified ± fibrous portions Variable signal on T2. In the active phase, heterogeneous pattern Usually, high ADC values on DWI Fibrous components may enhance intensely | Variable FDG metabolism | Paget disease (adults) Ossifying fibroma Meningioma Metastasis Chondrosarcoma Giant cell tumour |
Cherubism | Submandibular lymph node enlargement may be present | Well-defined, bilateral, multilocular, expansile, radiolucent lesions of the jaws in children Symmetrical enlargement of the mandible and maxilla Teeth displacement, absence of dental follicles | Symmetrical, multilocular pseudocysts in the jaws, with few irregular bony septa, usually without other craniofacial involvement Rounded scalloped lesion margins with marked bony expansion | Heterogeneous signal intensity Signal intensity changes in areas that are apparently normal on radiographs or CT | (Not indicated) | Central giant cell granuloma Noonan-like/multiple giant cell lesion syndrome Hyperparathyroidism |
Odontogenic keratocyst (OKC) in NBCCS | (Not indicated) | Multiple and expansile cystic masses of the jaws Radiolucent with sclerotic rim Unilocular or multilocular lesions May displace developing teeth, resorb roots of erupted teeth, cause tooth extrusion Rarely resorption of adjacent teeth | Corticated expansile cystic lesions with smooth or scalloped borders Density varies with viscosity of contents No detectable enhancement | Intermediate to high signal on T1 and heterogeneous signal on T2 May have low ADCs due to ortho-/parakeratin and/or haemorrhage No solid enhancing tissue, thin or no enhancing rim | (Not indicated) | Periapical (radicular) cyst Dentigerous (follicular) cyst Ameloblastoma |
Torus | (Not indicated) | Areas of increased bony density of variable size arising from the mid-portion of the hard palate (TP) or along the mandibular or maxilla margins (TM and TMax) | Often of fortuitous discovery Typical localisation in oral cavity Bone density of a non-infiltrating exophytic cortical bone lesion, without enhancement | Low signal intensity in T1 and T2 No soft tissue involvement and no enhancement | (Not indicated) | Osteoma |
Dermoid and epidermoid cysts | Well demarcated avascular homogeneous mass in epidermoid type Heterogeneous echostructure and minimal increase through transmission ± hyperechoic focus with posterior acoustical shadowing consistent with calcification in dermoid type Pseudosolid appearance | (Not indicated) | Epidermoid: low-density, well-demarcated cystic mass with fluid density material inside the lesion Dermoid: well-circumscribed cystic mass with fatty, fluid, calcified or mixed contents Typical location, ovoid or tubular morphology Depending on their location, DC may present as osteolytic lesions or may cause scalloping of the near bone | Epidermoid: homogeneous fluid signal (high signal on T2), diffuse high signal on T1 if high protein fluid. Typically restricted diffusion on DWI Dermoid: heterogeneous high signal on T2 (intermediate signal if fat, focal areas of low signal if calcifications, complex fluid signal on T1). Fatty elements show focal or diffuse high signal on T1 and low signal if fat saturation is used. May have restricted diffusion on DWI. Thin rim enhancement or none | (Not indicated) | Depending on the location of DC: Supraorbital region, floor of the mouth and cheek: Thyroglossal duct cyst Lymphatic malformation Ranula Abscess Intraorbital: Orbital infantile haemangioma Orbital lymphatic malformation Orbital venous malformation Nose (see below) |
Nasal dermoid sinus cyst (NDSC) | (See above) | No specific x-ray findings on the radiograph of the skull | Midline lesion anywhere from nasal tip to the anterior skull base at the foramen caecum Fluid attenuation cyst and tract from nasal dorsum to skull base within nasal septum Fat-containing mass (dermoid) No specific enhancement Bifid or deformed crista galli or cribriform plate with large foramen caecum Morphology: ovoid mass ± tubular sinus tract | The lipomatous content of the NDSC appears hyperintense on T1 and hypointense on fat-suppressed images (dermoid) Sagittal plane displays course of sinus tract from nasal dorsum to skull base Restricted diffusion on DWI (epidermoid) Rim enhancement or none | (Not indicated) | Nasal glioma Fronto-ethmoidal cephalocele Fatty marrow in crista galli Non-ossified foramen caecum |
Plexiform neurofibroma (PNF) | Lobular, serpiginous infiltrative soft tissue mass | Trophic changes and specific signs of bone involvement of the affected structures | Infiltrative trans-spatial appearance Mild contrast enhancement | Target sign: central T2 hypointensity in the multilobulated hyperintense mass Contrast enhancement of infiltrative solid mass (mild to moderate) | Hypermetabolism in sarcomatous transformation | Venous malformation Lymphatic malformation Sarcoma |
Venous vascular malformation (VVM) | Variable size of multilobulated, solitary or multiple, spongy and compressible lesion with vascular channels No arterial flow on colour Doppler Hyperechoic foci with posterior acoustic shadowing consistent with phleboliths (if present) | Characteristic phleboliths May show trophic changes of adjacent bones | Circumscribed or trans-spatial, lobulated soft tissue mass, isodense to muscle, with rounded calcifications (phleboliths), often drained by enlarged veins Variable contrast enhancement: patchy and delayed or homogeneous and intense No enlarged feeding arteries Bone remodelling of the adjacent bone | Multilobulated mass with variable signal intensity on T1 Cyst-like appearance of large vascular channels, hyperintense on T2 Smaller vascular channels appear more solid and with intermediate signal intensity Vascular signal voids on T2 due to enlarged dysplastic draining veins Phleboliths appear as rounded or oval signal voids Contrast enhancement is variable, may be mild to intense, delayed, heterogeneous or homogeneous Lymphatic component of VM do not enhance | (Not indicated) | Arteriovenous malformation Lymphatic malformation Infantile haemangioma Dermoid and epidermoid cyst |
Lymphatic malformation (LM) | Multicystic paediatric soft tissue mass with fluid–fluid levels Macrocystic LM (> 1 cm): soft, compressible anechoic cystic mass, usually with thin internal septations High echogenicity if haemorrhage or proteinaceous fluid Microcystic LM (< 1 cm): infiltrative solid-appearing mass of subcutaneous soft tissue, mildly hypo- or hyperechoic | (Not indicated) | Multilocular, fluid-attenuation mass, typically uniform, may contain foci of high attenuation due to haemorrhage or protein or low attenuation due to fat or lymph components Subtle fluid–fluid levels of blood products Contrast enhancement of septations in macrocystic LM | Largely bright fluid signal intensity mass with hypointense septa on T2 Fluid–fluid levels due to haemorrhage Bright signal intensity on T1 due to haemorrhage, protein, fat and lymph components Thin rim/septal contrast enhancement of macrocystic lesion. Confluent enhancement of infiltrating tissue in microcystic LM No high-flow vessels intrinsic to lesion | (Not indicated) | Venous malformation Infantile haemangioma Soft tissue sarcoma Soft tissue infection |
Cephalocele | Obstetrical US: soft tissue mass through osseous defect | Fronto-ethmoidal: midline frontal, intranasal or medial orbital bony defect | Heterogeneous, mixed-density mass variable amounts of CSF and brain parenchyma, extending through bony defect Intrathecal contrast fills subarachnoid space and surrounds soft tissue extending through bony defect (used only when MRI and CT still equivocal) CT cisternography may be useful in localising CSF leak, especially if CSF rhinorrhoea or otorrhoea is present Fronto-ethmoidal: crista galli may be bifid or absent. Deficient or absent cribriform plate Skull base: depicts osseous defect in skull base Temporal bone: focal bone defect in tegmen tympani or mastoid Petrous apex: unilateral or bilateral smooth expansile petrous apex lesion due to herniation of posterolateral wall of Meckel cave Enlarged petrous apex porus trigeminal notch | Soft tissue mass isointense to grey matter on T1 Hyperintense signal of CSF surrounds herniated soft tissue parenchyma on T2 Tissue may show hyperintense signal due to gliosis Mass showing contiguity with intracranial brain parenchyma and CSF No abnormal contrast enhancement or mild rim enhancement is noted within soft tissue Meninges may enhance in case of infection or inflammation | (Not indicated) | Depending on the location of cephalocele: Fronto-ethmoidal (frontonasal, nasoethmoidal, naso-orbital type) and skull base (nasopharyngeal, spheno-orbital and sphenomaxillary type): Nasal glioma Orbital dermoid and epidermoid Nasal dermal sinus Nasolacrimal duct mucocele Teratoma Temporal bone: Cholesteatoma with tegmen dehiscence Middle ear cholesterol granuloma Temporal bone arachnoid granulation Petrous apex: Petrous apex cholesterol granuloma Petrous apex congenital cholesteatoma Petrous apex mucocele |