[Frontal sinus osteoma as a cause of purulent meningitis].

Introduction: Osteomas are benign tumours located within bones or developing on them (1). The incidence of osteomas is as follows: frontal, ethmoid and maxillary, while they are extremely rare in the sphenoid sinus (2). Most often they are localized on sutures, and extremely rarely on occipital squama (3). They are often asymptomatic, and can be accidentally detected, by radiographic examination (4). The main clinical symptom is headache of varying intensity and quality, and in most cases not proportional to the size of the osteoma, which ranges from the size of pepper bean to the size of a child's head (5). In addition to headache, there can be sensitivity to pressure in the region of the frontal sinus (6). On exteriorization they give the symptomatology of the organ on which they develop. Depending on the direction of osteoma exteriorization, various complications may occur (6,7,8,9,10).

Case Description: A male patient born 1958, was admitted to the Department of Infectious Diseases on Nov. 29, 1996 with high temperature and strong headaches. The patient had had a traffic accident in 1989. X-ray did not show any injuries of cranial bones, but a frontal sinus osteoma has already been diagnosed. He had been suffering from occasional headaches several years back. Symptoms of the disease started three days prior to admission, with increased body temperature and headaches which persisted in spite of prescribed analgesics. Seven days prior to onset of the disease, the patient had had a cold. When admitted, he was conscious, oriented, with well developed osteomuscular structure. He did not vomit or have photophobia; meningeal signs were negative; febrile. Laboratory blood findings were normal, except for higher sedimentation (SE + 27) and higher blood sugar (BS = 8.1 mmol/l). Due to permanent diffuse headaches a lumbar puncture was performed on Dec. 1, 1996. Laboratory and microscopic examinations showed that the patient had purulent meningitis (Table 1). X-rays of the cranium showed a frontal sinus osteoma, starting from the frontal ethmoid cells and filling the entire right frontal cavity. Electroencephalogram dated Dec. 3 shows no signs of focal or diffuse electro-cortical dysfunction. An otolaryngologist was consulted who recommended surgical extirpation of the osteoma. Axial computerized tomography of the structures of endocranium in 5 and 10 mm sections was done on an outpatient basis on Dec 17, 1996. The findings confirmed existence of frontal sinus osteoma on the right side (without lesions of the frontobasal brain structures) and calcification of fhalx cerebri. After appropriate pre-operative preparation, surgery was performed in general endotracheal anaesthesia on December 6, 1997: Trepanatio sinus frontalis sec. Tato, evacuation osteomatis et obliteratio sinus frontalis lateris dextri. It was found intraoperatively that the right frontal sinus was entirely filled with whitish-yellow osseous tissue. The osseous tumour was completely immobile in relation to the surrounding tissues and filled the entire cavity of the frontal sinus, descending into both front enthmoids towards the right posterior ethmoid and penetrating the upper orbit wall over a radius of about 5 x 10 mm. The osteoma was carefully extirpated from the location with a drill and it was found that its pressure had denuded the dura in the right region of the cranial cavity with the diameter of about 1 cm2. The osteoma was removed in three osseous fragments, total size 4 x 2.5 x 1.5 cm. Upon removal of the osteoma, the sinus walls were explored for possible fracture, due to the head injury from 1989. No signs of fracture were found. Total obliteration of the right frontal sinus was made, with a closure of the nasofrontal channel and osteoplastic reconstruction of the frontal sinus wall. The postoperative course was regular.

Conclusion: This paper describes an osteoma of the frontal sinus in a 39-year-old patient. (ABSTRACT TRUNCATED)