Non-odontogenic tumors and pseudotumors of the jaws
Introduction :
Benign non-odontogenic tumors of the jaws constitute a polymorphic group. The vast majority are common to the rest of the skeleton.
Since clinical symptoms generally contribute very little, it is the radiological and especially anatomopathological criteria which will allow the final diagnosis to be made.
New WHO classification 2017
I/ Bone-forming tumors
Uncommon compared to their malignant counterparts, benign tumors originating in the bone are sometimes difficult to diagnose histologically.
1°/ True osteoma
Resulting from the proliferation of compact or trabecular bone within a membranous bone of periosteal or central location.
Often asymptomatic in subjects over 40 years of age, with slow growth, it is discovered late by a hard and well-defined swelling.
The radiological image is radio opaque, dense, unique and homogeneous with a tone similar to that of the tooth from which it remains independent.
Treatment: excision.
2°/ Palatine and mandibular torus
Exophytic and limited growth bone neoformation, frequently observed.
Palatine torus:
Located in the midline of the palatine vault, it forms a hard, oval swelling.
Mandibular torus :
In adults, it is a bony swelling formed at the expense of the internal cortex, above the mylohyoid line opposite the PM. Most often bilateral and symmetrical. Appears in the form of dense radiopacity, in continuity with the internal cortex.
Histologically:
Adult bone whose center is occupied by a mass of spongy bone.
Treatment :
Sometimes making it difficult to wear an additional prosthesis, their removal by modeling surgery is indicated.
3/ Osteoid osteoma:
- Exceptional
- Pain with nocturnal paroxysms relieved by salicylates
- Radio: characteristic, in the subperiosteal region: central osteolytic nidus punctuated by micro-opacities and surrounded by a zone of peripheral condensation.
- Histology: Trabeculae of osteoid bone (immature bone) with osteoblasts in richly vascularized connective tissue. Osteoclasts are fewer in number than osteoblasts.
4- Osteoblastoma
It is a benign osteoforming tumor, slowly evolving, circumscribed, expansive, but without peripheral osteogenic reaction. Its diameter varies from 1 cm to 10 cm. Three times rarer than osteoid osteoma.
- The clinic: Osteoblastoma is never asymptomatic, but the clinical signs are generally less significant than for osteoid osteoma; the pain is moderate, dating back several months, predominantly nocturnal, relieved in a quarter of cases by nonsteroidal anti-inflammatory drugs and aspirin.
The radio:
It appears as a central geode greater than 1 cm, well-defined, with the appearance of a calcified zone in the center depending on the stage, and ossifies completely at the final stage. It is surrounded by less condensation than that of the osteoid osteoma.
- Histologically, there is hypervascularized loose connective tissue, osteoblasts giving rise to newly formed osteoid tissue, as well as osteoclasts and giant cells.
Ps: Osteoblastoma poses several problems, particularly for the pathologist, due to the great radio-clinical and especially histological similarities with osteoid osteoma.
II°/ Osteocementogenic tumors: Cemento-ossifying fibroma, Cementing fibroma, Ossifying fibroma WALDRON 1970
1°/ Cemento-ossifying fibroma (FCO):
– It is a neoplasia consisting of fibrous tissue containing variable quantities of mineralized material resembling bone and/or cementum.
– Mainly affects the maxillae and especially the mandible at PM level.
– Exceptional in long bones.
– Slight female predisposition between 20 and 30 years old, in the form of slowly developing swelling of the affected bone sector with dental displacement and sometimes rhizalysis.
Radiology:
- In the early stage, the radiological image is essentially radiolucent, even pseudocystic. Fine opacities subsequently appear and gradually thicken.
- At a more advanced stage, the image consists of concentric bony trabeculae delimited on the periphery by a shell deforming the bony tables, the center of the image contains more regular opacities.
- Later the image will be completely radio opaque.
Histology:
Cemento-ossifying fibroma is formed of connective tissue rich in fibroblasts without mitosis with inclusion of calcified substance whose exact cementum or bone nature is often difficult to assess.
III°/ Cartilaginous tumors:
1- Chondroma:
– Frequent in men and exceptional at the maxillary level, it is preferentially located in the region:
Upper incisor, symphysis, mandibular body and condyle.
– Manifests as a slowly developing, painless bony swelling.
Radiology:
No typical image has been described, the chondroma presents in the form of + or – polycyclic osteolysis without peripheral osteocondensation.
Histology:
- The macroscopic appearance is firm and translucent.
- The histology of this tumor is dominated by the presence of small, rounded or stellate chondrocyte cells without nuclear atypia.
2- Chondroblastoma
- It is a rare, benign cartilaginous tumor, predominantly male,
- The maxillomandibular localization is almost exclusively located at the level of the
condyle.
- It generally occurs in young people, typically before the age of 25.
Clinic: a painless, slowly developing swelling of the pre-tragic region.
It may be associated with dental articulation disorders related to temporomandibular joint damage.
Radiological signs
A clear radiographic image of well-defined osteolysis, without a border of peripheral osteocondensation. Small trabeculations or microcalcifications may sometimes appear within this lesion.
Histology
Macroscopy: : finds a lobulated appearance with a gray-blue coloring
Microscopy: a cartilaginous matrix sometimes partially calcified, more or less polymorphic chondroblasts grouped into islets
IV°/Fibroblastic tumors:
Desmoid fibroma:
Painless swelling, variable in development, poorly limited.
It grows rapidly and spreads to soft parts.
Radiology:
Single or multilocular osteolytic image with sometimes rhizalysis.
Treatment :
The macroscopic appearance is such that enucleation is technically impossible, justifying a large resection.
Histogenesis:
Desmoid fibroma is currently considered not to be a genuine tumor but rather an anarchic repair process following trauma.
V°/ Tumors and pseudotumors rich in giant cells.
1°/ Giant cell tumors (formerly myeloplastic tumors).
- Usually located in the long bones, exceptionally in the jaws.
- Occurs between the ages of 20 and 40 in the form of bone swelling that is sometimes painful.
Radiology:
Image of mono or polygeodic osteolysis.
Histology:
Macroscopy = reddish-brown tumor, partly necrotic, hemorrhagic, pseudocystic.
Histological examination shows numerous very large giant cells with a very large number (40 to 50) of nuclei bathed in a matrix poor in collagen.
Treatment :
Large excision of healthy bone with or without restoration of bone continuity, in order to avoid the significant risk of recurrence or malignant transformation.
2°/ Central giant cell granuloma (reparative granuloma): Jaffé 1953
Localization exclusively at the level of the maxillae; frequent in the symphyseal region in 20-30 year olds.
Manifests as a bony swelling covered with brownish mucosa with changes in adjacent teeth (mobility, displacement)
Radiology:
Large geode with a rounded or scalloped outline, often crisscrossed by a few cottony or, on the contrary, very fine partitions (honeycombs).
Histology:
- Macroscopically, the enucleation product appears reddish brown, granular and hemorrhagic.
- The histological appearance varies according to the quantity and arrangement of giant cells; presence of hemorrhagic foci and hemosiderin deposits. Trabeculae of bone or osteoid tissue may be observed at the periphery.
Treatment :
Enucleation is the treatment of choice for central giant cell granuloma, followed by careful curettage. *
The evolution
Is often favorable even after incomplete excision.
3°/ Brown tumors of hyperparathyroidism:
Are lesions related to secondary hyperparathyroidism in the context of renal failure complicated by osteodystrophy.
- Radio: vast, finely partitioned gaps
- Histo: similar to giant cell granuloma.
The phosphocalcic balance and a parathyroid hormone dosage constitute the key to the diagnosis of primary hyperparathyroidism.
– Increase in the level of parathyroid hormone,
– Hypercalcemia,
– Hypophosphatemia,
4°/ Cherubism (cherubinism): familial multilocular cystic disease of the jaws.
It is a genetic condition in which the spongy tissue of the jaws is replaced by vascularized fibrous tissue, containing varying amounts of giant cells.
It is familial and is transmitted in an autosomal dominant manner; with variable expression.
Mandibular angles and ascending branches are hypertrophied
It begins around the age of 1 to 3 years, progresses during childhood and stabilizes then regresses at puberty, possibly disappearing by the age of 30.
In its mandibular location it appears in the form of a deformation of the bilateral masseteric region, painless and without neurological deficit giving a chubby appearance .
In its maxillary location, the eyeballs are moved upwards.
Dental malpositions are common as well as monstrous deformations in extreme cases.
X-ray:
Panoramic: shows numerous radiolucent images well-defined multilocular image bilateral polylobed soap bubble, symmetrical, without reaching the condyles with thinning and swelling of the cortices
Dental migration anomalies and frequent dental agenesis (2nd and 3rd lower molars).
The scanner: hypertrophic process of osteolytic tissue content, multilocular with interruption of the bone cortices.
Histology;
Appearance varies depending on the evolution:
- Young lesions: we find connective tissue rich in fibroblasts and numerous multinucleated giant cells.
- Old lesions: it is a dense fibrous connective tissue, poor in giant cells, with trabeculae of newly formed bone.
Treatment :
Therapeutic abstention with control biopsies to see the evolution. In certain cases remodeling surgery can be proposed.
Currently: biotherapy.
VI°/ Other connective tissue tumors. Nerve tumors.
1°/ True angiodysplasia and vascular tumors:
Hemangioma:
– Rarer in the jaws than in the skull and vertebrae.
– Mainly affects the female sex in its first decades.
– Affects the mandible more than the maxilla (2/3 of cases).
– Latent, it is revealed by hemorrhages (gingival bleeding or even cataclysmic hemorrhage after extraction of a mobile tooth*).
– It must be systematically considered in the presence of an angiomatous appearance of the mucosa, a pulsatile bone swelling.
Radio: appearance of a poorly defined, single or multi-geodic non-specific osteolysis. Only angiography or CT angiography will allow correct exploration of the lesion.
Ana-path. :
Macroscopy: dark red mass, hollowed out with microcavities and dotted with fibrous or bony tissue.
Histology:
Structure of cavernous angioma, with large lacunae lined with endothelium and filled with blood.
Treatment :
The treatment of high-flow angiodysplasia has truly evolved with the advent of hyperselective embolization.
2°/ Lipomas and leiomyomas:
They are exceptional in the skeleton and particularly in the jaws.
3°/ Nerve tumors:
– Particularly frequent in the cervico-facial area.
– Among the mandibular locations, schwannomas, also called neuromas, are the most common; they derive from the inferior dental nerve and are usually benign.
– Observed at any age without gender predisposition.
– Clinically latent, they sometimes result in bone swelling.
– Radio: reveals a monogeodic radiolucent image sometimes pushing back the dental canal.
VII°/ Neuroectodermal melanotic tumor. ( Melanotic prognoma )
– Rare tumor, deriving from the neural crest, it occurs in infants between 1 and 3 months and is never observed beyond 1 year.
– Its usual location is the maxilla in its anterior portion and some cases have also been described in the mandible or in other locations.
– More or less pigmented lesion located in the bone or appearing in the gum.
Radio:
The appearance produced is that of osteolysis with poorly defined contours, frequently compartmentalized by bony septa; the developing dental germs are often displaced.
Histopathology:
The tumor is made up of two types of cells:
* some resemble epithelial cells,
* the others are small, round, very chromophilic, pseudo-lymphocytic.
Treatment and evolution:
Despite the sometimes extensive nature of the lesion, excision is not followed by recurrence.
VIII°/ Langerhans histiocytosis (histiocytosis X)
Under the term histiocytosis X have been grouped (according to Lichtenstein 1953) three clinical syndromes having the same histological substratum :
- eosinophilic granuloma located mainly in the skeleton,
- Hand-Schüller-Christian disease, which combines cranial lesions with diabetes insipidus and exophthalmos
- Abt-Letterer-Siwe disease, which is highly progressive and is seen in infants.
The condition is characterized by the proliferation of Langerhans cells, hence its current name of Langerhansian histiocytosis.
The significance of this condition remains controversial: some believe it is a genuine tumor that develops at the expense of Langerhans cells; but most authors consider it a dysimmune disease that could result either from excessive stimulation of Langerhans cells or from dysfunction of immunosuppressive T lymphocytes.
IX – Bone and/or cementing dysplasias
1- Fibrous dysplasia:
Early 2nd decade , female gender +++
Slow evolution starting in childhood, stabilization at the end of growth, sometimes occasional evolutionary resumptions.
Radio:
– Rx aspect differs depending on the stage of development:
– Decalcification or radiolucency (young lesions).
– Gradually “frosted glass” appearance.
– – Dense foci with a “cotton-like” appearance.
Major feature: absence of demarcation line/healthy bone.
Histology
Connective tissue rich in fibroblasts + trabeculae of dystrophic bone with irregular contours.
Treatment :
Shaping surgery.
2- Cemento-osseous dysplasias
a- Periapical cemental dysplasia (periapical fibrous dysplasia)
- It affects middle-aged women (40-50 years old) and is mainly located in the region of the mandibular incisors; it sometimes affects several neighboring teeth.
- Radio: results in periapical osteolysis simulating an apico-dental cyst. However, the tooth in contact is healthy. Then an increasingly compact opacity is observed.
- Histopathology: microscopic study shows connective tissue dotted with more or less large clumps of a substance close to cementum.
- Evolution: the lesion is usually left in place due to the vitality of the adjacent tooth.
b- Florid cemento-osseous dysplasia (giant cementoma, multiple familial cementoma):
These cementomas are observed almost exclusively in middle-aged women of black ethnicity.
Radio:
Images of radiopaque masses disseminated in both maxillae, causing bone deformities often ulcerated and complicated by osteitis.
Histopathology:
– Areas of highly basophilic acellular cementum merging with the dental roots are observed.
– This lesion must be distinguished from a simple radicular hypercementosis more regularly arranged concentrically to the root.
Treatment :
– Therapeutic abstention in the absence of disorders
– Surgical treatment, when necessary, involves large en bloc resections.
Conclusion
Benign maxillary tumors are varied and multiple, deriving from different origins. No sign is pathognomonic to any of them.
A careful clinical examination and additional, prioritized and targeted tests are the only guarantees of an early diagnosis,
The anatomo-pathological examination is mandatory to make a positive diagnosis, to rule out or to confirm a presumptive diagnosis .
Non-odontogenic tumors and pseudotumors of the jaws
Cracked teeth can be healed with modern techniques.
Gum disease can be prevented with proper brushing.
Dental implants integrate with the bone for a long-lasting solution.
Yellowed teeth can be brightened with professional whitening.
Dental X-rays reveal problems that are invisible to the naked eye.
Sensitive teeth benefit from specific toothpastes.
A diet low in sugar protects against cavities.