Osteoma of the right and left frontal sinuses: signs, removal

Tumor-like bone formation that occurs in the airway cavity (frontal sinus), localized in the spongy substance of the frontal bone of the cerebral part of the skull, is defined as the osteoma of the frontal sinus. Osteoma is benign, the pathology code for ICD-10 is D16.4.

[1], [2], [3], [4], [5], [6], [7], [8]

Epidemiology

Domestic clinical statistics of osteoma of the frontal sinuses is unknown. It is noted that asymptomatic osteoma is found in a maximum of 3% of patients aged 20 to 50 years with CT of paranasal sinuses - quite by accident. In 2-2,5 times more often this pathology develops in men.

[9], [10], [11], [12],

Causes of the frontal sinus osteoma

To date, the exact causes of frontal sinus osseomy have not been established, but physicians associate the etiology of locally limited proliferation of bone tissue cells (osteocytes) with disruption of its formation (osteogenesis) and resorption due to increased activity of osteoblasts and osteoclasts-osteogenic bone cells.

Perhaps the causes of such violations include not only a genetically predisposed predisposition, but also infections: about 30% of patients had a history of chronic rhinosinusitis, although its causal relationship with osteoma formation could not be established.

It is assumed that the risk factors of this education may be traumatic brain injuries (including birth defects), metabolic pathologies (in particular, calcium), autoimmune diseases (systemic collagenoses).

Very rarely, frontal sinus osteoma is associated with  Gardner's syndrome (disease), the development of which is provoked by gene mutations.

[13], [14], [15], [16]

Pathogenesis

Investigating the pathogenesis of benign bone formation and bone tissue defects, the scientists discovered a number of disorders of its metabolism, regulation of which is the most complicated biochemical process. It passes with the participation of the pituitary somatotropic hormone; thyroid thyroid and calcitonin; parathyroid hormone (PTH); produced by the cortex of the adrenal cortisol; osteoprotegerin (a receptor protein that regulates the activity of osteogenic cells) and other enzymes and hormones.

For example, for as yet unknown reasons, in adults - especially in cases of non-sutura metopica (frontal, i.e., metoplastic suture) - the activity of the bone isoenzyme of alkaline phosphatase, which ensures the development of the skeleton of the head  and the growth of bones in children and adolescents , can be increased  .

By the way, the airborne frontal bone of the skull is formed in the fetus from the cells of the mesenchyme (connective tissue of the embryo) and consists of two parts. With the passage of time, the mesenchyme transforms into bone tissue (by ossification from the ossification points located in the area of the orbits and the superciliary arches). One frontal bone becomes only to six or seven years due to the fusion of the frontal suture. And the development of the frontal sinuses is activated in the pubertal period and lasts up to 20 years.

There is also a connection between the formation of osteoma of the craniofacial spongy bones with the anomalies of catabolism of collagen proteins of the intercellular matrix, with the imbalance of non-collagenous bone tissue synthesized by osteoblasts (osteocalcin, osteopontin, osteonectin, thrombospondin), as well as impaired metabolism of calcitriol and cholecalciferol (vitamin D3).

[17], [18], [19], [20], [21]

Symptoms of the frontal sinus osteoma

Superficial osteoma, the first signs of which - a slowly increasing dense convexity (exostosis) of a rounded shape on the forehead - is painless. According to histological studies, it consists of a mature, largely mineralized plate-like bone and is defined as a compact frontal sinus osteoma. Usually the formation is one-sided, located near the cranial sutures: osteoma of the left or osteoma of the right frontal sinus.

If the formation consists of a spongy (diploid) bone component with an admixture of fibrous tissue and adipose tissue cells, this is a spongy or spongy frontal sinus osteoma. There may also be a mixed osteoma.

The formation growing intracranially on the back wall of the frontal sinus or on the inner side of the frontal bone on the left side is the osteoma of the basal sections of the left frontal sinus, on the right - respectively, of the right frontal sinus. Most of them are formed by a dense immature bone tissue, often with a fibrous nucleus and the presence of active osteoblasts and osteoclasts, due to which their growth is maintained.

It is in such cases that the bone tumor, gradually increasing, presses on the nerves localized nearby, structures of the brain and facial skull, triggering the symptoms of the osteoma of the frontal sinus:

• persistent headaches (often with nausea and vomiting) due to increased intracranial pressure;
• pain in the face;
• protrusion of the eyeball (exophthalmos or proptosis);
• the inability to open the eye normally (due to the lower eyelid - ptosis);
• unilateral deterioration of vision with possible double vision (with suppression of the supraorbital nerve);
• hearing loss, ringing and noise in one ear (with the localization of education closer to the wedge-frontal suture).

Complications and consequences

Although the invasion of the osteoma into the cerebral part of the skull is rare, but the larger its size, the more likely the serious consequences and complications associated with pressure on the frontal lobe of the brain with irritation of parts of the motor cortex (primary motor and premotor), frontal oculomotor field and others structures. This can lead to disruption of coordination of movements, convulsions, psychogenic disorders.

Even less often the consequence of such osteoma is erosion of the dura mater or intracranial infection (meningitis, brain abscess).

Most often, the localization of the osteoma closer to the nasal cavity is manifested by worsening drainage of one or more paranasal sinuses (leading to chronic sinusitis), as well as difficulty in nasal breathing.

[22], [23], [24]

Diagnostics of the frontal sinus osteoma

In the diagnosis of frontal sinus osteoma, the main role is played by instrumental diagnostics: radiography, computer and magnetic resonance imaging.

In this case, the x-ray of the osteoma of the frontal sinus gives an accurately depicted smooth-contour shadow of high intensity, adjacent to one of its walls.

[25], [26], [27], [28]

Differential diagnosis

Differential diagnosis should rule out the presence of:

• osteomyelitis;
• ossified fibrous dysplasia;
• osteopoxic;
• osteogenic sarcoma;
• osteoblastoma;
• osteoblastic metastases.

Treatment of the frontal sinus osteoma

The methods of drug therapy of this pathology have not been developed, and in the absence of symptoms, the treatment of small-sized frontal sinus osteoma is not performed.

A significant size of the formation located on the outside of the frontal bone is considered as an indication for its removal as an aesthetic defect of the facial part of the skull.

With the spread of osteoma inside the skull and the presence of symptoms due to the squeezing of a number of located structures of the brain, surgical intervention is shown - either by surgical excision of education or by endoscopic laser vaporization.

Prevention

To reveal a genetic predisposition to violations of osteogenesis is not yet possible, therefore, there is no preventive measure for the development of this pathology.

[29], [30], [31]

Forecast

With a superficial location of the osteoma, the prognosis is positive, since these formations are not malignant. Also, specialists consider the frontal sinus osteomy to be beneficial, if at its growth inside the cranium accompanied by neurologic symptoms, a qualitative surgical intervention was performed in time.