Simple diagnostic approach for mandible and maxilla lesions.

Transcription

1 Simple diagnostic approach for mandible and maxilla lesions. Poster No.: C-1285 Congress: ECR 2015 Type: Educational Exhibit Authors: A. Gargallo Vaamonde, A. Burguete, N. Baraibar Argota, M. M Mendigana Ramos ; Pamplona/ES, Etxauri/ES Keywords: Neoplasia, Education and training, Cysts, Radiation therapy / Oncology, MR, CT, Oncology, Head and neck, Bones DOI: /ecr2015/C-1285 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 43

2 Learning objectives To show the spectrum of mandibular and maxilla lesions we can find in CT scan. To highlight clinical and imaging features of benign and malignant maxillary lesions. Pictorial review demonstrating most important points we should evaluate to assist with diagnosis. Background Mandible and maxilla can present a wide variety of pathology with diverse origin, including tumoral, infectious, traumatic, metabolic or congenital lesions. They suppose only a 3% of the total head and neck cancer; however, focal lesions are really frequent incidental findings in routine examinations and radiologist should be able to discern those lesions potentially malignant. Classically, mandibular lesions have been classified depending on its origin as odontogenic or non-odontogenic (bone, nerves or blood vessels). The World Health Organization (WHO) classifies them as benign or malignant, with further subdivisions based on predominant tissue involved Fig. 1 on page 3 Page 2 of 43

3 Fig. 1: Based on the 2nd edition classification of the WHO histological typing of odontogenic tumours. References: - Pamplona/ES Differential diagnosis of mass-like lesions should include also pathologies with an exogenous origin like metastasis, osteomyelitis, osteoradionecrosis or direct tumour invasion from floor of mouth lesions. Actually MDCT allows a precise characterization of these lesions, resulting in an essential diagnostic tool; nevertheless, some of them may have similar imaging appearances, so familiarity with embryologic characteristics, adequate knowledge of tooth and jaw anatomy(fig. 2 on page 4 Fig. 3 on page 5 and Fig. 4 on page 6) and clinical findings are crucial. Regardless, in some cases biopsy is indispensable for the diagnosis. Images for this section: Page 3 of 43

4 Fig. 1: Based on the 2nd edition classification of the WHO histological typing of odontogenic tumours. Page 4 of 43

5 Fig. 2 Page 5 of 43

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8 Findings and procedure details A multitude of pathologies may affect the maxilla and mandible. We review main clinical and imaging features necessary for a precise radiologic evaluation to provide the differential diagnosis of these lesions. Most important demographic/clinical data that we should take into account are: The age of the patient. Symptoms or inflammatory process associated. Growth velocity. From a radiological point of view a systematic approach is essential. We should consider four main features and other secondary characteristics that should be present in the report. Density: Cystic, solid or mixt appearances Fig. 5 on page 19 Relation to the tooth (odontogenic or non-odontogenic):if the injury is associated with a tooth we consider it as odontogenic. Otherwise we consider a non-odontogenic origin like bone, neurogenic or vascular lesions. However in large lesions it can be difficult to determine the association to the tooth because teeth may have been included secondarily in the lesion. Location regarding to the tooth: Relationship to a particular part of a tooth is really useful in the diagnosis of odontogenic jaw lesions. We regard three possible locations Fig. 6 on page 19. a. Periapical: Adyacent to the root (for example apical cyst). b. Pericoronal: About a crown (for example follicular cyst). c. Inter-root: Between the roots of an edentulous area. Displacement or destruction of adjacent tooth: Fig. 7 on page 20 Other radiological features: Unilocular or multilocular appearance Margin: It may be sharp, sclerotic or ill-defined. Page 8 of 43

9 3. 4. Size of the lesion. Cortical interruption and periostic reaction. Following this points we overview main lesions affecting the jaw with some example cases to illustrate most important findings. 1. Cystic Lesions: A. Odontogenic: Radicular Cyst (periapical cyst): Fig. 8 on page 21 Most common odontogenic cyst (around a 70% of total cystic lesions) Normally asymptomatic lesions between the third and fifth decade of life. Secondary to inflammatory process in caries tooth, that spreads through the tooth root and subsequently forms a cyst Location regarding to the tooth: Periapical. Radiologic features: well-circumscribed, unilocular, radiolucent lesion, with sclerotic rim. Ill-defined margin or growth can indicate secondary infection Fig. 9 on page 22. MRI images shows high signal intensity on T2-weighted images and enhancement of the wall of the cyst after contrast administration. Usually they measure less than a centimetre, but sometimes they can be large and displace tooth structures. Cyst generated after exodontia are called residual cyst, most of which derived from radicular cyst. Follicular Cyst (dentigerous cyst): Fig. 10 on page 23 It is the second most common odontogenic cyst. Most of them are asymptomatic and become evident between the third and fourth decades of life. It forms around the crown of an unerupted tooth (usually third inferior molar tooth). Page 9 of 43

10 Radiologic features: well-circumscribed, unilocular, radiolucent area that includes the crown of an unerupted tooth. They often may be large, displace adjacent teeth and produce cortical expansion and thinning. Odontogenic Keratocyst: Fig. 11 on page 24 Unusual (3-10% of all cystic lesions) Peak of incidence during second and third decades of life. Characteristically located in the posterior region of the body and ramus of the mandible. Radiologic features: well-defined, unilocular or multilocular radiolucency with sclerotic margin that can expand the bony cortex. Sometimes it is associated to an unerupted tooth and its named as primordial cyst Fig. 12 on page 25 High rates of recurrence after surgery and can present aggressive growth. Two types: parakeratinizing that is the typical variant and orthokeratinizing which present significantly less aggressive behaviour. Multiple OKC are associated to the Gorlin-Goltz Syndrome. B. Non-odontogenic: Incisive Canal Cyst (Nasopalatine Duct Cyst): Fig. 13 on page 26 It is the most common non-odontogenic cyst. Arise from epithelial remnants in the incisive canal. More frequent in the fourth and sixth decades of life. Usually asymptomatic, but sometimes produce displacement of the roots of the central incisor teeth. Radiological features: Round or ovoid, well-defined, uniloculated, radiolucent lesion located in the midline. Traumatic Bone Cyst (Solitary, Simple, or Hemorrhagic Bone Cys). More prevalent in the second decade of life (men>women). Page 10 of 43

11 Traumatic injury produces intramedular hematoma and subsequently leads to pseudocyst formation. Located in the medullar of the jaw it has irregular and poorly defined margins. Pseudocyst size and shape are widely variable. CT density and MR T1-weighted images signal can varied depending on the evolutive stage of the hematoma. Aneurismal Bone Cyst More frequent in children and young adults (women>men). Some authors have proposed a traumatic origin. They present fast growth, usually asymptomatic. Radiological features: Expansive lesion with clear limits, uni or multilocular appearance. MRI can show fluid-fluid levels that are characteristic 50% recurrence rate after surgical treatment Stafne Cyst (Static Bone Cavity) Usually incidental finding detected around the fifth decade of life (men>women). It is typically located in the medial surface of posterior mandible below the mandibular canal. Strictly speaking it is a pseudocyst originated from a cortical defect. Radiological features: well-circumscribed, monolocular, round, radiolucent lesion, between 1 and 2 cm in size with sclerotic/cortical margins. It can contain part of the submandibular gland or adjacent fat. 2. Solid lesions: A. Benign odontogenic tumours: Odontoma: Fig. 14 on page 27 Most common odontogenic tumour. Page 11 of 43

12 Usually detected during second decade of life. It contains multiple components of the teeth (enamel, dentin, cementum, and pulp), therefore, it is also called mixed tumour. Most odontomas cause impaction or resorption of adjacent teeth. In the initial stage they shown as radiolucent area because of bone resorption by the odontogenic tissues. In late stages it develops progressive calcification, initially characterized by small, mottled calcify densities that sometimes leads to radiopaque masses surrounded by a lucent ring. They can be subdivided in two groups: Compound odontomas, which have radiographically identifiable tooth components (abortive teeth), and complex odontomas, which contain multiple masses of dental tissue with amorphous calcifications. There are other three subtypes of odontomas: Odontogenic mixoma: Uncommon (3-6% of the total of odontogenic tumours). Arise from myxoid stroma of the dental pulp. It occurs most often in the second and third decades of life and most common located within mandible. Painless but it can present fast growth and have locally aggressive behaviour. High rates of recurrence. Radiological features: Radiolucent and multilocular lesion with straight or curve trabecular appearance. Usually associated to and unerupted tooth. Ameloblastic fibroma: Rare. Associated with developing teeth (children) Radiological features: Well-defined, pericoronal, radiolucent lesion, usually multiloculated and associated with impacted teeth. Often located within the posterior mandible. Radiographic differentiation from other odontomas is not possible. Adenomatoid Odontogenic Tumor: Rare (3% of all odontogenic tumours). More frequent in the second decade of life. (women>men). Page 12 of 43

13 Normally located in the maxilla. Radiological feutures: Well-circumscribed radiolucent lesions with punctate calcifications, located around a tooth crown, that can displace or prevent the eruption of teeth. (differential diagnosis with follicular cyst). Ameloblastoma: Fig. 15 on page 28 Peak of frequency between the third and fifth decade of life. Clinically asymptomatic with slowly growth (sometimes detected with large size). Arise from enamel-forming cells (ameloblasts). It is usually located at the posterior region of the jaw, around molar teeth. Radiological features: Uni or multilocular radiolucent lesion with honeycombed or bubble appearance. It can cause erosion of the bone cortex and extended to the soft tissue. Sometimes it produces rhizolysis or displacement of the tooth roots. MRI demonstrates mixed patterns with solid and cystic components, thick walls and septas that enhanced after contrast administration. Local aggressive behaviour. Approximately a 1% of them become malignant. Calcifying Epithelial Odontogenic Tumour (Pindborg tumor.) It can be presented in a wide range of age (women=men). Radiological features: Poor defined multilocular lesion with mixed density and scattered calcifications. Usually appears around the crown of an unerupted pre-molar or molar tooth. Cementoblastoma: Rare tumour, more common under 25 years of age (men > women). It is secondary to cementoblast dysfunction, which consist of formation of a cementum or cementum-like mass connected with a tooth root. Radiographical features: well defined lesion with central dense radiopaque material surrounded by a radiolucent area. Attached to a tooth root (frequently the first molar). Can cause bone cortical expansion and root displacement. Page 13 of 43

14 Surgery is curative in most cases. Periapical Cemental Dysplasia (PCD): This entity is a rare lesion that occurs more often during the fourth and fifth decades of life. (women > men). It is always associated to the roots of teeth, because is caused by a proliferation of connective tissue from the periodontal membrane. Radiological features: Initially we can see a well-circumscribed radiolucent lesion at the apex of the tooth, and progressively evolves to a radiopaque mass surrounded by a radiolucent border. Sometimesit can be multifocal and is known as florid cemental dysplasia (florid cemento-osseous dysplasia). B. Benign non-odontogenic tumours: Can be found in other parts of skeleton. Fibrous dysplasia: Fig. 16 on page 29 Most common detected under 30 years of age. (Men=women). Bone is replaced by fibrous or fibro-osseous tissue. Radiological features: It can be found in two stages. Initially it has radiolucent density with ill-defined margins, and subsequently calcified with a trabecular aspect, rendering the lesion partially radiopaque. Bone cortical can be expanded and sometimes produce clinical symptoms secondary to vascular or neural entrapment. Ossifying Fibroma (Cemento-Ossifying Fibromas, Cementifying Fibromas): Fig. 17 on page 30 Usually detected between the third and fourth decade of life. (women>men). Typically located within the posterior region of the mandible. Radiological features: Encapsulated lesion with well delimited boundary (useful to distinguish from fibrous dysplasia). It can appear radiolucent, radiopaque or with mixed opacity depending on the degree of calcification (later stages are more radiopaque). We also report a rare case of desmoplastic fibroma Fig. 18 on page 31, which consist in fibroblastic bone lesion that histologically resembles the desmoid tumor of soft tissue. This variant of fibroma frequently Page 14 of 43

15 demonstrates aggressive behavior, often causing tooth mobility, extensive bone destruction, and has high rates of recurrence. Paget's disease: Most common over 40 years of age. Is originated by osteoblasts and osteoclasts dysfunction resulting in poorly mineralized and deformed bones. Maxillar area is frequently involved and can produce compressive symptoms of the base skull nerves. Radiological feature: It depends on the phase of the disease: 1. Osteolitic phase: Characterized by bone resorption and radiolucent appearance. Midex phase: Toggles lytic and blastic areas with cortical thickening. Sclerotic phase: Formation of dense bone with poor vascularization Malignant transformation to osteosarcoma has been reported in the mandible, mostly if the region has been previously irradiated. Exostosis: These lesions are localized outgrowths of bone. Three types of exostosis are identified according to their location: the torus mandibularis (located in the lingual surface of the mandible), the torus palatinus (arises in the middle of the hard palate), and multiple exostoses (maxillary). Radiological features: They characterized by areas of increased bony density projecting from the mandible or maxilla. They can be differentiated from osteomas by their typical location. Osteoma: Usual occurrence between fifth and sixth decade of life (women>men). Radiological features: they have a characteristic radiographic appearance. Well-circumscribed, sclerotic bony masses attached by a broad base or pedicle to the surface of the mandible. Osteochondroma: Fig. 19 on page 32 This benign lesion is caused by an overgrowth of cartilage at a growth site. Page 15 of 43

16 When they are located in the jaw do so more frequently in the coronoid and condylar processes. Radiological features: radiopaque extraosseous projection with a cartilaginous cap. Chondroma: Rare in the mandible and maxilla. They arise from cartilaginous remnants in bone. Radiological features: Lytic lesions in the body of the mandible with slowgrowing. Giant cell tumour: Most common in the second decade of life. (women>men). 2/3 located within the jaw, usually in the anterior region and can cross the midline. Radiological features: Radiolucent expansive multiloculated lesion with trabeculation, fine septa and ground glass appearance. Usually thins the cortical, which can be interrupted in large lesions. Root resorption or displacement can be observed. Include a variety of pathologies: Giant cell granuloma, giant cell tumor and brown tumor of hyperparathyroidism. Langerhans histyocitosis: It is a rare disease caused by abnormal proliferation of Langerhans cells (abnormal cells derived from bone marrow). Clinical manifestations can range from isolated bone lesions to multisystemic disease. Three variants have been described: Letterer-Siwe disease (disseminated acute histiocytosis), Hand-Schuller-Christian disease (disseminated chronic histiocytosis), and eosinophilic granuloma (localized histiocytosis). Radiological features included small, rounded radiolucencies with welldefined borders. Hemangioma: They are present in 12% of all children by 1 year of age. (women>men) Page 16 of 43

17 They growth during the first year of life and later involutes slowly with partial or complete resolution. Radiological features: ill-defined radiolucent lesions with late contrast enhancement, usually involving the inferior alveolar canal. C. Malignant tumours: They can be classifies into four main groups. Carcinoma of the oral cavity: Fig. 20 on page 33 Most of the solid maxillary and mandibular malignant lesions are originated from the surrounding mucosa of the oral cavity that secondary invades them. Squamous cell carcinoma arising from adjacent mucosa is the most common, but there are other entities that we should take into account, such as mucoepidermoid carcinoma and adenoid cystic carcinoma. Clinical examination and background are key to the diagnosis. Radiological Features: Early stages are characterized by cortical erosion in the alveolar ridge. Later an irregular radiolucent cavity may be formed. Normally there is no evidence of bony sclerotic or periosteal reaction. Osteosarcoma: Fig. 21 on page 34 Primary osteogenic sarcoma usually affects children and young adults with a peak incidence in the third decade of life. (men=women). Usual clinical symptoms are swelling and pain. Radiological features: There are three types of presentation; bone destruction with ill-defined margin, an area of sclerosis or a mixed pattern. The osteoblastic type is the most common one in the mandible. In some cases we can find a sunburst appearance caused by mineralization of tumour spicules Fig. 22 on page 35. Cortical destruction, with soft tissue invasion, is a common finding in advanced cases. Sometimes a thickening of the periodontal membrane may be the earliest radiographic finding of osteogenic sarcoma of the jaw. Mestastasis: Fig. 23 on page 36 Metastasis to the maxilla and mandible are sometimes the first manifestation of an occult primary malignant tumour. Page 17 of 43

18 Mandibular location is four times more common than maxillar. Frequent primary sites of origin are kidney, lung, breast, thyroid, prostate, and stomach. But other tumours origins have been reported. Radiological features: Lesions can be lytic or blastic (breast and prostate). Posterior body and angle of the mandible are most commonly affected. Primary odontogenic tumors: Primary odontogenic carcinomas are rare. This group of tumors includes odontogenic carcinoma, primary intraosseous carcinoma, and malignant ameloblastoma. Some cases of carcinomatous transformation of OKCs and other cystic lesions have been reported. 3. Tumor-like lesions: Osteoradionecrosis: Fig. 24 on page 37 Osteoradionecrosis is cause by irradiation of bones that leads to damage of osteocytes and endothelial cells, which results in tisular necrosis. It may develops months to years following radiation therapy. It is clinically characterized by pain and ulceration in a previously irradiated area. Prevention of osteradionecrosis is part of the reason why all teeth of questionable prognosis are removed before the start of a course of radiotherapy. Radiological features: Vary depending on radiation dose and duration. Areas of osteoradionecrosis contain both sclerotic and lytic components with poorly defined borders and enlarged trabecular spaces that can expand or deformed the cortical of the bone. Sequestered bone can be identified within the region. Osteomyelitis: Fig. 25 on page 38 Osteomyelitis is an infectious process of the bone and marrow originated as a result of an odontogenic infection or secondary to a systemic disease. Radiological features: Acute suppurative osteomyelitis usually has no radiological manifestation in early stages and progressively produces single Page 18 of 43

19 or multiple irregular radiolucencies. Chronic suppurative osteomyelitis can shows a wide range of density from radiolucent to mixed or radiopaque lesions. Low-grade infections can lead to sclerosing osteomyelitis, in which, bone is deposited along the osseous cortex and existing trabeculae, resulting in thickening of them. Focal and diffuse types have been described. The diffuse one involves the jaw in most cases. Soft tissue can be affected and lead to fluid collections. In Fig. 26 on page 39 and Fig. 27 on page 40 we present a systematic approach to the diagnosis of the main mandibular and maxillar injuries basing on mayor radiological features and prevalence of the lesions. Images for this section: Fig. 5 Page 19 of 43

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21 Fig. 7: Tooth displacement with rizholisis Page 21 of 43

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42 Conclusion Adequate knowledge of dental and jaw anatomy is essential to guide the diagnosis of mandibular lesions and differenciate between odontogenic and nonodontogenic sources. The main radiological findings we should value include: Density, relation to the tooth, location regarding to the tooth and displacement or destruction of adjacent tooth. Imaging is not always conclusive for the diagnosis but helps to narrow the differential diagnosis and allows to detect warning signs. Personal information A. Gargallo Vaamonde, A. Burguete, N. Baraibar Argota, M. M. Mendigana Ramos; Servicio de Radiología del Complejo Hospitalario de Navarra, Pamplona, Spain. References Dunfee BL1, Sakai O, Pistey R, Gohel A. Radiologic and pathologic characteristics of benign and malignant lesions of the mandible. Radiographics Nov-Dec;26(6): Peter M. Som, Hugh D. Curtin, Head and Neck Imaging 4ª Ed. Mosby, 2003 HARNSBERGER et al. Diagnóstico por imagen. Cabeza y cuello.(2ºed) Madrid. Marban, Kramer IRH, Pindborg, Shar M. Histological typing of odontogenic tumours. In: World Health Organization-international histological classification of tumours. 2nd ed. Berlin, Germany: Springer-Verlag, 1992; 1-42 Abellan, D. et al: Anatomía y patología dental y mandibular. SERAM Avril L, Lombardi T, Ailianou A. Radiolucent lesions of the mandible: a patternbased approach to diagnosis. Insights Imaging Feb;5(1): doi: /s Epub 2013 Dec 10. Devenney-Cakir B, Subramaniam RM, Reddy SM, Imsande H, Gohel A, Sakai O. Cystic and cystic-appearing lesions of the mandible: review. AJR Am J Roentgenol. 2011;196:WS66-WS77. doi: /AJR Bisdas S, Chambron Pinho N, Smolarz A, Sader R, Vogl TJ, Mack MG. Biphosphonate-induced osteonecrosis of the jaws: CT and MRI spectrum Page 42 of 43

43 of findings in 32 patients. Clin Radiol. 2008;63: doi: / j.crad Page 43 of 43