Differential Diagnosis of Radiolucent Lesions-2 PDF

10/6/2024 1 Non‐odontogenic cysts and cyst‐like lesions - Simple bone cyst Usually in those less than 20 years old. Almost all occur within the mandible Unknown aetiology Most are asymptomatic, and are often incidentally identified...

10/6/2024 1 Non‐odontogenic cysts and cyst‐like lesions - Simple bone cyst Usually in those less than 20 years old. Almost all occur within the mandible Unknown aetiology Most are asymptomatic, and are often incidentally identified radiologically 2 1  10/6/2024 cortical border --> well defined, sharp opaque // thin, smooth sclerotic border --> less well defined (but has irregular appearance) // thick, irregular but clear Simple bone cyst - Radiological features Unilocular well‐defined corticated lucency. This corticated border is often delicate in appearance Some regions may not demonstrate the presence of a cortex but remain well defined The borders may be scalloped Usually no expansion, although larger lesions may demonstrate minimal expansion This lesion often scallops between the roots of teeth The lamina dura is usually preserved Tooth displacement and root resorption is rare 3 Simple bone cyst – D/D Keratocystic odontogenic tumour -KCOTs usually demonstrate more corticated margins and are more likely to cause root resorption and tooth displacement than SBCs Radicular cyst -Apical lamina dura is effaced. Usually demonstrates a tear‐drop morphology of at the root apex. SBC borders often scallop between the roots. The radicular cyst, unless small or deflated, is expansile 4 2  10/6/2024 Well-defined corticated lucent lesion Well-defined corticated lucent lesion extending extending superiorly between the 45 superiorly between the 48, 47 and 46 roots. Most of and 46 roots. Most of the radicular the radicular lamina dura is preserved. No root lamina dura is preserved. No root resorption or tooth displacement resorption or tooth displacement 5 Well-defined corticated lucent lesion thinning the inferior cortex. The 47 lamina dura and 48 follicular cortex are preserved. No root resorption or tooth displacement Well-defined corticated lucent lesion extending superiorly between the roots of 48 and 47 The lamina dura is largely preserved. No root resorption or tooth displacement There is thinning of the inferior cortex The mandibular canal is not deflected 6 3  10/6/2024 Well-defined non-expansile corticated lucent lesion with slight thinning of the labial cortex, which remains preserved. Note preservation of the incisor lamina dura 7 Nasopalatine duct cyst; incisive canal cyst Usually asymptomatic until large, when swelling is the most common first clinical feature. This swelling is classically fluctuant 8 4  10/6/2024 Nasopalatine duct cyst- Radiological features Well‐defined, lucent, corticated lesion centred at the incisive canal Often asymmetric Expansile when sufficiently large. This can be seen labially and palatally. It may also expand into the nasal cavity and maxillary sinus, elevating the cortical floors The expanded maxillary cortices are often thinned with focal regions of effacement Displaces teeth and resorbs roots when sufficiently large 9 Nasopalatine duct cyst-D/D Large incisive canal - Maximal dimension of the canal/foramen of more than 6 mm is more likely to reflect a cyst The normal incisive canal presents with a large variation in morphology and size Evidence of expansion, tooth displacement or resorption favours the presence of a nasopalatine duct cyst Radicular cyst - The radicular cyst is centered upon a root, usually apically 10 5  10/6/2024 Effacement of the 21 and 22 lamina dura with no resorption Note that root resorption is usually eventually seen with larger lesions Well-defined corticated lucent focal widening of the incisive canal Accessory neurovascular canal and foramen 11 Focal well-defined corticated lucent widening of the incisive canal and foramen 12 6  10/6/2024 Spot the diagnosis ? Periapical Rarefying Osteitis 13 14 7  10/6/2024 FIBROOSSEOUS LESIONS 15 Fibrous dysplasia Benign condition of bone Can be: where there is abnormal – Monostotic remodelling with presence of – Polyostotic dysplastic fibrous tissue and varying amounts of – Can be associated with immature bone McCune–Albright Most common benign bone May present with painless disorder syndrome facial swelling and asymmetry Larger lesions may impinge on nerves 16 8  10/6/2024 Fibrous dysplasia – Radiological features Solitary lesions are almost always Expansion is an important feature, limited to one bone unless the lesion is extremely small Borders are often described as There is often thinning and alteration of ill‐defined the cortical architecture, sometimes Often hyperdense to normal bone with focal regions where the cortex is but some may present with focal absent regions of increased density as well The architecture of the lamina dura of as focal regions which are the teeth is often altered and may be hypodense and lucent compared indistinct. Teeth are often displaced. with normal bone Root resorption is rare Ground‐glass internal appearance Mandibular canal will classically deflect is most frequently seen the canal superiorly 17 Fibrous dysplasia – Differential diagnosis Chronic osteomyelitis- Demonstrates periosteal response and sequestra Osteogenic sarcoma -More Ossifying fibroma –More aggressive bone growth usually tumour‐like growth and with speculation expansion where the normal Paget disease - Usually older morphology is not preserved. age group and usually There may be surrounding bilateral lucent margin 18 9  10/6/2024 Expansile lesion with ground-glass internal appearance Cortex alterations Expansile lesion with internal heterogeneous appearance including focal opaque and lucent regions with ill defined borders 19 Expansile lesion with internal homogeneous ground-glass appearance Sinus floor not seen Internal ground-glass appearance , Expansile with focal cortical thinning 20 10  10/6/2024 21 Cemento‐osseous dysplasia Benign focal change of normal bone to fibrous tissue and metaplastic bone and/or cementum‐like material Most often identified in the 40 year age group Three subtypes have been described – Periapical osseous dysplasia (periapical cemental dysplasia) – Florid osseous dysplasia occur in multiple lesions of the jaw – Focal cemento‐osseous dysplasia its a mixed lesion both lucent (due to resorption) and opaque 22 11  10/6/2024 Cemento‐osseous dysplasia-Radiographic features ▪ Immature lesions are usually lucent, with Rarely, simple bone cysts are sclerotic margins associated with these lesions In time, internal focal opacity(s) appears The lamina dura of the involved and increases in size as the lesion teeth is usually absent or altered matures over years. These opacities are but the periodontal space is often usually homogeneous preserved. Root resorption is rare Mature lesions present as opaque Expansion is often seen with larger lesions demonstrating a surrounding lesions, where the thinned cortices lucent margin (band) with sclerotic are often largely preserved borders Larger lesions may displace the Occasionally, these lesions can be mandibular canal internally homogeneous, demonstrating a ground‐glass appearance 23 Cemento‐osseous dysplasia- D/D ▪ Early/immature lesions Cementoblastoma – Chronic periapical inflammatory Irregular root resorption, lesion - When there are no internal Usually painful opacities, these lesions can be Ossifying fibroma –The radiologically almost identical ossifying fibroma has more of Mature lesions a mass effect, especially on the affected dentition Bone island - No surrounding lucent margin Cemento‐osseous dysplasia is often multiple; ossifying Odontoma fibroma is a solitary lesion 24 12  10/6/2024 25 radiopacity is much more dense than the cementum density multiple-florida 26 13  10/6/2024 Ossifying fibroma - cemento‐ossifying fibroma, cementifying fibroma, juvenile ossifying fibroma Composed of fibrocellular tissue In the jaws, it is considered to be with varying amounts of most common within the posterior mineralised bone/cementum‐like body of the mandible, although it material also presents elsewhere Can be aggressive to be more Often presents as a painless aggressive in the younger patient swelling, sometimes with displacement of teeth More often seen in females. Much less common than cemento‐osseous dysplasia and fibrous dysplasia 27 Ossifying fibroma – Radiographic features Tumour‐like mixed‐density expansile Usually demonstrates tumour‐like mass lesion effect: Well‐defined borders, which may be – Displaces anatomic structures such corticated. A surrounding lucent as the mandibular canal, paranasal margin may be present, possibly sinuses and nasal cavity only at one or a few aspects of these lesions – Displaces teeth with effacement of Internal density varies substantially, the lamina dura. depending on the amount of – May cause root resorption. mineralised material. It can be essentially lucent. – Expanded jaw cortices are often The pattern of the mineralised thinned and altered. material also varies, from – The expanded cortices are classically ground‐glass appearances (similar largely preserved, although focal to fibrous dysplasia) to homogeneous opacities (similar to regions of cortical absence may be cemento‐osseous dysplasia) seen. Adjacent bone can be sclerotic 28 14  10/6/2024 Ossifying fibroma – Differential diagnosis Fibrous dysplasia - Borders Giant cell lesions - Presence of internal septa are less well defined and there is no surrounding lucent Lesions with internal margin calcifications, including calcifying Expansion is not tumour like cystic odontogenic tumour, adenomatoid odontogenic tumour Root resorption is rare and the rare calcifying epithelial Cemento‐osseous odontogenic tumour (Pindborg dysplasia are usually tumour) - The internal calcifications of multifocal. Less tumour‐like these lesions are usually small growth, especially in relation to teeth 29 30 15  10/6/2024 31 32 16  10/6/2024 Benign Tumours Involving the Jaws- Ameloblastoma More common in the third to sixth decades Most commonly seen in the posterior mandible. Maxillary lesions most commonly occur posteriorly Usually asymptomatic until it causes painless swelling Large lesions may involve adjacent structures 33 Ameloblastoma -Radiological features Presents as a multilocular lesion The desmoplastic subtype may with well‐defined corticated or demonstrate more internal septa, sclerotic borders which are more irregular and The internal septa are classically sclerotic in appearance thick and curved. Some may demonstrate the classic ‘soap Unless small, the jaw cortices are bubble’ appearance. usually expanded and thinned, The cystic locules vary in size with regions of effacements The unicystic ameloblastoma is When involving a tooth root, there unilocular (lucent internally) and is often substantial root often demonstrates extreme resorption expansion for its size. Most are associated with the unerupted Tooth displacement is often seen mandibular third molars when the lesion abuts the crown 34 17  10/6/2024 Ameloblastoma –D/D Giant cell granuloma -Internal Ossifying fibroma - When this lesion septa are usually much finer than demonstrates appearance of internal the ameloblastoma. Also usually septa, they tend to be larger and less seen in the younger population distinct Odontogenic myxoma- Keratocystic odontogenic tumour - Presence of one or a few straight Internal septa are uncommon and septa is a feature. Typically mandibular lesions demonstrate mild demonstrates mild expansion for expansion for size size Dentigerous cyst -May not be able to Aneurysmal bone cyst - Fine radiologically differentiate from the internal septa and typically unicystic ameloblastoma in a extremely expansile pericoronal relationship with an unerupted tooth 35 36 18  10/6/2024 37 38 19  10/6/2024 Calcifying epithelial odontogenic tumour- Pindborg tumour Asymptomatic until expansion is noted More commonly seen in the posterior mandible, many associated with unerupted teeth Rare locally invasive epithelial odontogenic tumour with amyloid‐like material where there may be calcific foci 39 Calcifying epithelial odontogenic tumour-Radiological features May be unilocular or multilocular May demonstrate variable internal calcifications Borders are also variable, ranging from well‐defined cortex to poorly defined destructive margins May displace teeth 40 20  10/6/2024 Calcifying epithelial odontogenic tumour-Differential diagnosis May resemble unilocular lucent lesions such as cystic lesions, multilocular lesions or lesions which demonstrate internal calcifications - The more common location of the calcifying epithelial odontogenic tumour (CEOT) in the posterior mandible, associated with an unerupted tooth, may be a useful feature 41 42 21  10/6/2024 Ameloblastic fibroma Rare ; Most occur in the first and second decades of life Asymptomatic unless large enough to cause expansion or interfere with tooth development/eruption Most are seen within the posterior mandibular alveolar process 43 Ameloblastic fibroma - Radiological features Well‐defined, usually corticated lesion Usually unilocular. May be multilocular, usually when larger Larger lesions cause expansion with cortical thinning May interrupt tooth development/eruption or displace teeth 44 22  10/6/2024 Ameloblastic fibroma -Differential diagnosis Dentigerous cyst -May be very Ameloblastoma - Demonstrates coarser septa than ameloblastic difficult to differentiate from a pericoronal ameloblastic fibroma fibroma. Substantial root resorption Less likely to be a dentigerous cyst is a feature if the margins are not at the Giant cell granuloma - cementoenamel junction (CEJ) Demonstrates fine internal septa. Keratocystic odontogenic Larger giant cell granulomas tumour (KCOT) -Within the typically demonstrate lobulated mandibular body, the KCOT expansion with a tendency for demonstrates limited expansion substantial tooth root resorption for size. It is usually lucent internally and usually only Aneurysmal bone cyst demonstrates one or a few septa Odontogenic myxoma when large 45 46 23  10/6/2024 Adenomatoid odontogenic tumour Rare ; Most occur in the second decade of life. More common in females Within bone (central), the follicular type (pericoronal relationship to an unerupted tooth) is more common. Can occur in soft tissues (peripheral) Most are seen in the maxillary canine region 47 Adenomatoid odontogenic tumour- Radiological features Well‐defined corticated lesion Some may be lucent but most demonstrate variable internal calcifications Larger lesions will often displace teeth and may expand and thin the jaw cortices 48 24  10/6/2024 Adenomatoid odontogenic tumour- Differential diagnosis Ameloblastic fibro‐odontoma - Most commonly seen in the posterior mandible Calcifying epithelial odontogenic tumour - Most commonly seen in the posterior mandible Dentigerous cyst - Less likely to be a dentigerous cyst if the margins are not at the CEJ Keratocystic odontogenic tumour - Can appear similar to the adenomatoid odontogenic tumour (AOT) which is internally lucent 49 50 25  10/6/2024 Odontogenic myxoma Usually asymptomatic until larger, when there may be some expansion and/or discomfort More commonly seen within the body of the mandible, most common in the posterior segment 51 Odontogenic Myxoma - Radiological features Usually presents as a well‐defined, corticated, multilocular lesion where one or a few of the septa are flat/straight rather than curved May appear as unilocular lucent lesions Limited expansion May displace teeth, although root resorption is usually not a feature 52 26  10/6/2024 Odontogenic Myxoma - Differential diagnosis Other lesions with multilocular appearance, including ameloblastoma, giant cell granulomas, aneurysmal bone cysts, keratocystic odontogenic tumour and vascular malformations - The presence of one or a few flat/ straight septa among others is a feature of the odontogenic myxoma 53 54 27  10/6/2024 55 Odontoma Asymptomatic ; Associated with unerupted teeth Often contributes to altered eruption or impaction of adjacent teeth May contribute to the malformation of the adjacent teeth 56 28  10/6/2024 Odontoma – Radiographic features Opacity of variable internal appearance with surrounding lucent margin (lucent band/zone) and a corticated border Internal density is variable, depending on the proportion of the various dental tissues Often affects the position, development and eruption of the adjacent teeth, which are occasionally malformed 57 Odontoma – Differential diagnosis Cemento‐osseous dysplasia - Mature lesions may resemble the complex odontoma CODs are often multiple and the borders are usually sclerotic Ossifying fibroma -Odontomas are usually denser, with variable presence of enamel 58 29  10/6/2024 59 Cementoblastoma Occurs more commonly in males, most often younger than 25 years old Most commonly seen at the mandibular first molar region centred apically Pain is commonly reported. The pulp status of the involved tooth is usually normal 60 30  10/6/2024 Cementoblastoma - Radiological features Well‐defined, largely opaque lesion with a surrounding lucent margin (band) and a corticated/slightly sclerotic border, centred at the apical aspect of a tooth root Internal opaque architecture varies from being unstructured to a sunburst/‘spokes of a wheel’ appearance Root resorption is commonly seen Expansile when sufficiently large. 61 Cementoblastoma - Differential diagnosis Mature periapical osseous dysplasia The lucent margin (band) around the internal opacity is usually less defined and the surrounding opaque border is wider, often more sclerotic in appearance.. In addition, root resorption is not commonly seen with periapical osseous dysplasia and these lesions are more likely to be multiple, and are asymptomatic Bone island - No surrounding lucent margin with corticated border. Usually internally homogeneous and root resorption is only occasionally seen 62 31  10/6/2024 Cementoblastoma - Differential diagnosis Hypercementosis -Surrounding periodontal ligament space is usually much narrower and well defined. Usually internally homogeneous with no resorption Reactive sclerosis related to a periapical inflammatory lesion - Usually ill defined with no surrounding lucency. It demonstrates a periapical hypodense/lucent appearance or widening of the apical periodontal ligament space 63 64 32  10/6/2024 Osteoma A benign, slow‐growing, mature When involving the mandible, they most bony prominence at the periosteal commonly occur at the posterior surface mandible, often the medial aspect of the ramus or inferior border of the Three types can be seen, posterior body. They may also be seen consisting of: at the condyle and coronoid processes – compact bone (ivory osteoma) May be solitary or multiple. Gardner – cancellous bone syndrome should be considered when – combination of compact and there are multiple osteomas cancellous Usually asymptomatic, often Most commonly occurring within incidentally identified, unless large with the paranasal sinuses (especially a mass effect or causing clinically the frontal sinus and ethmoidal detectable asymmetry air cells, skull vault and mandible 65 Osteoma – Radiological features Well‐defined, focal, opaque prominence of variable bony appearance Internally varies from being homogeneous and isodense with cortical bone (ivory osteoma) to those with variable internal cancellous bone appearance and varying thickness of the overlying cortical bone Larger osteomas displace the adjacent soft tissues. Those occurring within the paranasal sinuses potentially distort the sinuses and may contribute to occlusion or narrowing of drainage pathways 66 33  10/6/2024 Osteoma – Differential diagnosis Osteochondroma of the mandibular condyle and coronoid process -Osteochondromas demonstrate more irregular morphology with more heterogeneous, sometimes sclerotic, internal appearances 67 Sessile bony prominence with Internally homogeneous and smooth periosteal surface isodense with cortical bone 68 34  10/6/2024 Ethmoid osteoma Sphenoid osteoma 69 Stylohyoid ligamentous ossification Bone-like opacities of the stylohyoid ligaments 70 35  10/6/2024 Sialoliths Radiological features Well‐defined opacity with variable size, morphology and internal architecture. The classical sialolith is ovoid/elongated with an internal laminated appearance Most commonly seen within the duct of the submandibular salivary gland. opacity projected over the inferior body of the mandible posteriorly 71 SPOT THE DIAGNOSIS Gardner syndrome Osteoma Supernumerary Impacted Bone island tooth 23 72 36  10/6/2024 Malignant Tumours Involving the Jaws - Radiological features Internal appearances- Usually Borders - Most demonstrate lucent. There may occasionally be poorly defined invasive borders, residual bone remnants within which may demonstrate irregular Osteoblastic metastatic lesions are lucent extensions into the adjacent usually sclerotic marrow spaces Multiple sclerotic foci involving several Occasionally, multiple ‘punched bones of the head and neck should out’ lucencies with slightly more raise the suspicion for metastatic defined borders may be seen. disease Most commonly associated with multiple myeloma Osteogenic sarcomas variably produce tumour bone Some malignancies may sometimes not demonstrate Mucoepidermoid carcinoma involving aggressive borders, e.g. bone often presents as a multilocular mucoepidermoid carcinoma lesion 73 Malignant Tumours Involving the Jaws - Radiological features Sometimes the edges of the destroyed cortex may be slightly raised; this is Maxillary or mandibular considered a type of periosteal response cortices- When a malignant associated with aggressive lesions (Codman lesion extends to or is centred at a triangle) bony boundary, there is usually cortical destruction, often with occasionally there is a lamina periosteal irregular edges response adjacent to the cortical lesion; the periosteal response over the destroyed Periosteal response at the cortex is usually also destroyed involved cortex- Most do not occasionally spiculation (sunburst demonstrate a periosteal response, appearance) is seen, i.e. multiple linear unless there is secondary infection opacities extending outwardly from the site of cortical involvement; this is a form of periosteal response classically described in association with the osteosarcoma 74 37  10/6/2024 Malignant Tumours Involving the Jaws - Tooth displacement and root resorption are Radiological features not typically seen. However: Dentoalveolar structure root resorption is occasionally seen iIrregular widening of the periodontal teeth may occasionally appear to be in a ligament spaces of the teeth displaced position if a significant amount Destruction of the lamina dura of tooth of surrounding bone is destroyed roots Sometimes, all or most of the alveolar This malignant widening of the bone around the teeth is destroyed, giving periodontal ligament spaces and the classically appearance of ‘teeth floating destruction of the lamina dura may in space involve any surface of any tooth root Mandibular canal Destruction of follicular cortices of Where a malignant lesion extends to this unerupted teeth. There may be canal, the borders are usually destroyed displacement of the calcified dental structures within the follicle There is usually irregular widening with focal regions of canal border destruction 75 76 38  10/6/2024 77 39