ODONTOGENIC TUMORS
INTRODUCTION Odontogenic tumors are tumors located exclusively in the jaws.
They constitute a heterogeneous group whose structure is more or less similar to one of the stages of odontogenesis. I. REMINDER OF ODONTOGENESIS *Each dental bud contains an epithelial outline, the enamel organ and a connective portion = the papilla of ecto-mesenchymal origin and secretes dentin. *Between these 2 tissues (epithelial outline, enamel organ) there is an internal layer of non-secreting cylindrical cells = preameloblasts *Preameloblasts transform into ameloblasts which ensure the secretion of enamel II. PRINCIPLES OF CLASSIFICATION Odontogenic tumors can be classified into 3 groups: 1-Purely epithelial tumors reminiscent of the structure of the enamel organ. 2-Tumors combining epithelial and connective structures 3-Tumors consisting exclusively of ecto-mesenchymal connective tissue. III. BENIGN TUMORS
A. Epithelial 1- Ameloblastoma: Rare (1/%), arises from the odontogenic epithelium. Clinical : frequent in males, 4th to 5th decade , slow growth, long asymptomatic and discovered incidentally, sometimes facial deformation or dental displacement. Location : jaws+++; mandibles 80% Radiology: polygeodic osteolysis (soap bubbles) Macroscopy:
– Section slice: sometimes a solid mass, sometimes a multilocular cystic mass – Resection limits are important. Microscopy: * Lobules of epithelial cells embedded in a stroma rich in vessels. * Each follicle is made of: – A peripheral layer of cubic or cylindrical cells of the pre-ameloblastic type. – In the center: disjointed epithelial cells reminiscent of the stellate reticulum of the enamel organ. – Evolution: * Bone cortical rupture with diffusion into the soft parts * Frequent, multiple recurrences 2- Epidermoid odontogenic tumor: It derives from the remains of the dental lamina – Clinic: between the 2nd and 7th decade , frequent in the 3rd decade , no sex predilection. – Location : mandible and maxilla – Radiology : unilocular osteolysis, sometimes multicentric foci. -Microscopy : islands of epidermoid cells, resting on a basal layer of flat cells, with microcalcifications. -Treatment : curettage -Evolution : local aggressiveness, recurrences are rare. 3-Calcified odontogenic epithelial tumor (Pindborg tumor) 1958 -Clinic : rare, all ages 20 – 60 years (peak at 40), both sexes -Location : jaws = mandibles 2/3, maxilla 1/3, painless mass of slow growth. -Radiology : osteolysis with irregular contours, near the crown of an impacted tooth. -Microscopy : epithelial component reduced to small islands or trabeculae of cells with signs of degeneration; abundant calcifications and amyloid deposits. -Evolution : complete resection => cure. B- Epithelial and connective tissue tumors Ameloblastic fibroma : Clinical : child and adolescent (< 21 years) Location : always mandible (molar-premolar region) and associated in ¾ of cases with an impacted tooth. Radiology : bone swelling, well-limited osteolysis Microscopy : tumor with two components : – Epithelial = 2 aspects: lobules bordered by a layer of cubic or cylindrical cells and centered by cells resembling the stellate reticulum. – Conjunctiva = loose, populated with spindle-shaped fibroblasts Treatment = excision C- Ecto-mesenchymal tumors: 1- Odontogenic fibroma : rare tumor, arises from the mesenchymal tissue of the dental outline in contact with the dental root or a crown of an impacted tooth. Macroscopy : well-circumscribed nodule, firm consistency. Microscopy : fibroblasts with collagen fibers with vestiges of odontogenic epithelium. 2-Odontogenic myxoma: young adult or adolescent (<30 years) most often located in the mandible . Clinical : rarely painful swelling – tooth displacement, tooth loss. Radiology : single or multi-tissue osteolysis. Macroscopy : grayish tumor, soft, poorly defined. Microscopy : stellate or anastomosed connective cells by fine extensions embedded in mucoid material. Treatment : simple enucleation. 3- Cementoblastoma: in contact with a dental root always located in the molar and premolar region of the mandible (young subject 2nd 3rd decade) Clinical : latent tumor. Radiology : in contact with a dental root in the process of resorption, well-limited opacity. Microscopy : mounds or extensive areas of irregular cementum. Treatment : simple enucleation.
IV-MALIGNANT TUMORS A-Carcinomas 1. Malignant ameloblastoma Presence of cytonuclear atypia and abnormal mitoses and sometimes metastases. 2- Primary intraosseous squamous cell carcinoma : Rare (60-70 years) women > men. Clinical : painful tumor, abnormal dental mobility. Radiology : osteolysis with poorly defined contours. Microscopy : plexiform lobules-trabeculae, palisade on the periphery with keratinization in the center. Sometimes undifferentiated carcinoma. 3- Malignant transformation of odontogenic cyst B-Sarcomas 1- Odogenic fibrosarcoma : rare 2-Odogenic carcinosarcoma: exceptional
V/ BONE TUMORS: A- BENIGN TUMORS 1) Bone tumors
Osteoid osteoma and osteoblastoma ;
Osteoma (very common craniofacial location).
2) Cartilaginous tumors
Chondroma;
Osteochondroma (solitary / exostosing disease);
Chondroblastoma ; Chondromyxoid
fibroma
3) Connective tissue tumors :
– Fibrous dysplasia is very common craniofacial location.
– Giant cell tumors B/ MALIGNANT TUMORS
1) Osteosarcomas : these are primary bone tumors whose cells produce immature osteoid bone tissue (osteogenesis)
– Observed in half of cases between 10 and 20 years of age.
– Clinically: pain with the appearance of swelling.
– Radiologically: areas of osteolysis and osteocondensation, cortical rupture, and image of anarchic osteogenesis in a grass fire. 2) Chondrosarcoma : Primary malignant tumor of the bone, producing cartilage
3) Ewing’s sarcoma
CONCLUSION Odontogenic tumors are quite rare in current practice but very varied. The role of the pathologist is to make a definitive diagnosis and assess the prognosis. Total excision when possible allows complete cure.
Bibliographic references
1 – Chomette G, Auriol M. Oral cervico-facial histopathology (pp.51-57) Masson, Paris, 1986. 2 – Olgac V, Koseoglu BG, Aksakalli N. Odontogenic tumors in Istanbul: 527 cases. Br J Oral Maxillofac Surg 2006; 44:386-8.
3 – Fernandez AM. Odontogenic tumors: a study of 340 cases in Brazilian population. J Oral Pathol Med 2005; 34:583-7.
4 – Lu Y, Xuan M, Takata T, Wang C, He Z, Zhou Z, Mock D, Nikai H. Odontogenic tumor: a demographic study of 759 cases in a Chinese population. Oral Surg Oral Pathol Oral Radiol Endod 1998; 86:707-14.
5 – Simon EN, Merkx MA, Vuhahula E, Ngassapa D, Stoelinga PJ. A 4 – year prospective study on epidemiology and clinicopathological presentation of odontogenic tumors in Tanzania. Oral surg. Oral Pathol Oral Radiol Endod 2005; 99:598-602.
6 – Ladeinde AL, Ogunlewe MO, Bamgbose BO, Adeyemo WL, Ajayi OF, Arotiba GT, Akinwande JA. Ameloblastoma analysis of 207 cases in Nigerian teaching hospital. Quintessence Int 2006; 37:69-74.
7 – Arotiba GT, Ladeinde AL, Arotiba JT, Ajike SO, Ugboko VI, Ajayi OF. Ameloblastoma in Nigerian children and adolescents; a review of 79 cases. J Oral Maxillofac Surg 2005; 63:747-51.
8 – Ruhin B, Guilbert F, Fouret P, Ghoul S, Berdal A, Bertrand JC. Maxillary tumors; ameloblastoma: current data and perspectives. Rev Stomatol Chir Maxillofac 2005; 106: 1s64
ODONTOGENIC TUMORS
Wisdom teeth can cause infections if not removed.
Dental crowns restore the function and appearance of damaged teeth.
Swollen gums are often a sign of periodontal disease.
Orthodontic treatments can be performed at any age.
Composite fillings are discreet and durable.
Composite fillings are discreet and durable.
Interdental brushes effectively clean tight spaces.
Visiting the dentist every six months prevents dental problems.