X-ray signs of benign tumors

X-ray diagnostics of benign odontogenic tumors

Distinguish odontogenic and neodontogenic benign tumors of the jaws. Among odontogenic neoplasms, odontomas and ameloblastomas are most common.

Odontoma - a benign tumor consisting of various tooth tissues (enamel, dentin, cement, pulp, fibrous tissue), develops mainly in the age of up to 20 years. Usually, patients enter the radiology examination with complaints about the delay of eruption of permanent teeth. Sometimes odontomas are discovered by chance during a radiographic study on another occasion.

According to the WHO classification, a composite and complex odontoma is distinguished. In the composite odontome all tooth tissues are represented at different stages of their formation, in complex - containing unmodified tissues of tooth and soft tissue component. Compound odontomes are in most cases localized on the upper jaw in the frontal region, complex - mainly on the lower jaw in the region of the first-second molars.

On the roentgenogram, odontomes have a high intensity, consist of a number of calcification centers of irregular shape, tooth-like fragments or teeth at different degrees of formation.

The contours of the odontis are distinct, sometimes wavy, scalloped, and on the periphery a band of clarification is visible, due to the presence of a capsule. With suppuration of the odontoma, the contours of the surrounding tissue become indistinct, fistulous passages may appear.

Odontomas grow expansively, causing displacement, thinning of the cortical plates of the jaw, swelling, asymmetry of the face, are prone to eruption into the oral cavity.

Lmeloblastoma (adamanthinoma) is a benign tumor that develops from the proliferating odontogenic epithelium located in the connective tissue. Usually it is diagnosed in the 4-5th decade of life. In 80% of cases, ameloblastoma develops on the lower jaw, in 20% - on the upper jaw. In the lower jaw, in 70% of cases, it is localized in the region of molars and branches, in 20% - in premolars and 10% in the incisors zone.

On X-ray patterns, ameloblastoma has the appearance of polycystic (multi-chamber) formation or a single cystic cavity. Polycystic ameloblastoma resembles a picture of bubble soap bubbles: it consists of a number of foci of bone and bone tissue destruction, round and oval, separated from each other by bone septa.

The picture of multicameral is sometimes due to the fact that the tumor enters the spongy and cortical parts of the bone at different depths.

Ameloblastoma causes deformation of the lower jaw due to its swelling, while in some parts of the jaw displacement, thinning and interruption of cortical plates are noted. The teeth in the tumor growth zone are displaced, their roots sometimes resorbed. If there is no secondary inflammatory component, then the reaction of the periosteum is absent. The impression of the interruption of the cortical plate of the jaw can be caused not only by destruction, but also by its displacement.

One or more non-cut teeth may be located in the tumor. The mandibular canal is shifted downwards.

Differential diagnosis with other cystic lesions of the jaws, in particular with osteoclastoma, is possible only on the basis of the results of histological examination.

Of non-dentonous tumors, osteomas, osteoclasts, and hemangiomas are most common.

Osteoma is a mature benign tumor that develops from a differentiated bone tissue. Depending on the structural features distinguish compact, spongy and mixed osteomas.

Most often, osteomas are localized in the paranasal sinuses, usually in the frontal and latticed bones and on the lingual surface of the lower jaw.

On the roentgenogram, the peripherally located osteomas have the form of rounded bone formation on a broad base or narrow pedicle, with clear, even contours emerging from the bone. On the walls of the frontal and maxillary sinuses they are determined in the form of dense bone mass, they can germinate into adjacent areas.

Multiple osteomas of the upper and lower jaws are sometimes combined with supercomplete teeth, polyposis of the large intestine.

X-ray diagnosis of osteoma in most cases does not cause difficulties. When placed in the posterior regions of the hard palate and on the lingual surface of the anterior mandible, difficulties arise in differential diagnosis from the palatal and mandibular musculoskeletal (torus palatinus and torus mandibularis).

Osteoclastoma (osteoblastoklastoma, giant cell tumor). On the lower jaw, osteoclasts are more often localized (in 10% of all cases) than in other parts of the skeleton. They are most often diagnosed during the 3rd decade of life; osteoclastomes are characterized by a relatively slow growth.

Depending on the features of the radiographic picture, cellular, cystic and lytic variants are distinguished by osteoclast. In the cellular version, against the background of the destruction sites, a cellular-trabecular structure is revealed-a large number of cavities of various shapes and sizes separated by thin bone septa.

The cystic form is represented by a cystoid cavity of round or oval shape with distinct contours. As the tumor grows, it causes swelling and thinning of the cortical plates of the jaw.

In the case of the lytic variant, the diagnosis of which is associated with great difficulties, the osteoclastoma is defined as a single edge foci of destruction, sometimes uneven in intensity, with rather distinct contours.

The contours of the osteoclast on the border with the unaffected bone are visible although fairly well, but not as clearly as with radicular cysts. There is no reactive osteosclerosis at the edges of the tumor.

As osteoclastomy grows, the displacement, thinning and discontinuity of the cortical layer, bloating of the jaw are noted. Intermittence of the cortical layer and germination in the peri-lateral soft tissues and under the mucous membrane are not evidence of the aggressiveness of its course or malignancy.

Neoplasm causes deformation of the jaw, root resorption, mixing and mobility of the teeth. On the upper jaw, the tumor can germinate into the maxillary sinus, the orbit, the nasal cavity, causing deformation of the face.

On the upper jaw, the osteoclastoma affects predominantly the alveolar process and is represented by foci of destruction of irregular shape with polycyclic contours. Leading to protrusion, thinning and interruption of the cortical plate of the jaw, the tumor sprouts into peri-axial soft tissues, causing deformation of the face.

Since swelling occurs predominantly in the buccal lingual direction, an x-ray of the mandible is axially projected to assess the state of the cortical plates.

To osteoclastomes belong and localized on the alveolar process giant-cell epulids, which, as they grow, cause the formation of marginal bone destruction.

Osteoclastoma should be distinguished from keratokisty, ameloblastoma, myxoma, fibrous dysplasia, intraosseous hemangiomas. The radiological picture of the lytic form may resemble that of osteogenic sarcoma. Differential diagnosis, especially for tumors located on the upper jaw, is possible only on the basis of the results of histological examination.

After radiotherapy, there is an increase in the reparative processes in the form of thickening of the cortical plates of the jaw and bone beams. At the same time cellular and cystic forms can turn into a lytic, and even the rate of growth accelerates.

Hemangioma. Vascular tumors - hemangiomas appear in the peri-mandibular soft tissues or inside the bone and consist of proliferating blood vessels. The lower jaw is affected by the bowl, among the sick more women. Hemangiomas are more often detected between 10 and 20 years.

Some authors attribute hemangioma to dysembryoblastic tumors, which arise as a consequence of congenital malformation of blood vessels. In children of the first year of life, congenital hemangiomas sometimes undergo reverse development. With hemangiomas of the maxillary soft tissues, shadows of phlebolites and angiolites with a diameter of 5-6 mm are sometimes seen on the photographs. Hemangiomas appearing in the near-maxillary soft tissues, exerting pressure on the bone, cause an edge saucer-shaped defect. In children, hemangiomas disrupt the development of the jaws and teeth rudiments.

The radiological picture of the hemangiomas of the jaws is extremely polymorphic: in the form of a single cystlike cavity with clear or fuzzy contours or multiple foci of destruction of bone tissue of various shapes and sizes (a picture of "soap bubbles").

With the development of hemangiomas from the vessels of the mandibular canal, a foci of dilution of round or oval form along the canal is revealed.

Hemangioma can cause thickening of the bone trabeculae, as if in the form of rays diverging from one center (picture of "wheel with spokes").

Intraosseous hemangiomas, as they grow, cause displacement and thinning of cortical plates, and in some cases can lead to their destruction. Periodic layering, as a rule, is absent. The teeth located in the tumor growth zone are mobile, their roots are resorbed. When pressure is applied to the crown, the teeth are "heated", and after the pressure is stopped they occupy the former position.

When removing teeth located in the arterial hemangioma zone, profuse bleeding that threatens life may occur.

Fibrous dysplasia refers to tumor-like lesions. At the heart of the pathological process is congenital malformation of the bone formation, arising both in the embryonic and postnatal period and characterized by a violation of the transition of mesenchymal tissue and its derivatives - connective and cartilaginous tissues - into the bone. The disease is most often found in the period of active growth of the jaw and facial bones - at the age from 7 to 12 years.

Depending on the involvement of one or more bones of the skeleton, the mono- and poly-osseous forms are distinguished. Not only the bones of the facial and cerebral cranium are affected, but also other parts of the skeleton. The polyosmal form of the disease is often combined with various endocrine disorders.

The radiological picture of fibrous dysplasia is diverse and reflects the pathological and anatomical nature of the process. In the early stage of the development of the process, the focus of rarefaction of bone tissue with clear or fuzzy contours is determined.

The defeat of the jaws is often mono-osa. On the lower jaw, the rarefaction site, usually located in the thickness, has an oval or ellipsoidal shape. The upper jaw is affected somewhat more often by the lower one, the orbit is involved in the process, and the maxillary sinus can become obliteration. The asymmetry of the face increases, the formation and eruption of teeth can be disturbed, and their displacement occurs. Resorption of the roots is possible, but the teeth remain immobile. Sometimes the closing cortical plates of the holes in the affected area are absent. Deformation of the alveolar process occurs predominantly in the buccal lingual direction. The enlargement of the jaw is sometimes accompanied by pain, which makes it possible to suspect chronic osteomyelitis.

As the osteoid tissue ripens, sclerosis foci appear, initially usually along the periphery of the dilution site. Subsequently, the phenomena of calcification accrue, its foci merge and on the roentgenogram are determined in the form of compaction sites of high or medium intensity (a picture of "frosted glass"), without clear boundaries passing into the surrounding bone.

Sometimes the increase in the asymmetry of the face stops only after 20 years (by the time puberty and the cessation of bone growth).

Albright syndrome includes a triad of symptoms: single or multiple foci of fibrous dysplasia in the bones, premature puberty in girls, skin pigmentation. The increase in foci occurs simultaneously with the growth of the child, in the future their stabilization is noted. The radiological picture is the same as in fibrous dysplasia.

Cherubism is a peculiar form of dysplasia, in which only the facial skull is affected, is hereditary in nature. The disease proceeds slowly painlessly at the age of 2 to 20 years. Affected lower (mostly areas of angles and branches) and upper (the bottom of the eye socket, hillock) jaw, while there is a shift of the eyeballs up, which gives the child's face an original expression ("the face of the cherub"). Venular processes of the lower jaw, as a rule, are not involved in the pathological process.

The disease begins at the age of 1 year - 2 years, diagnoses it in 3 years - 5 years; then it progresses, and by the age of 30 the patient's condition has stabilized. The face acquires the usual outlines. Boys are more often ill. The lesion focus consists of a vascularized proliferating fibrous tissue containing a large number of multinucleated giant cells. The course of the disease is usually painless. The bone is swollen due to the formation of a multitude of racemes of various shapes and sizes, the cortical layer is thinned and is interrupted in some areas. There is also a monocystic form of lesion. There are various anomalies in the development of the teeth (dystopia and retention, dysplasia of teeth rudiments, root resorption).