[A huge frontal sinus pyocele extending into the cerebral falx - a case report (author's transl)]

A 50-year-old male was admitted to us presenting a bulging of 5 X 6 cm in size on the forehead. His general condition was excellent and neurological status was normal. The mass in the forehead was soft and showed a fluctuation. On the plain skull films, a lobulated bone defect of 5 X 4 cm in size was noticed in the frontal bone and the frontal sinus completely disappeared. Carotid angiograms revealed posterior displacement of the supraclinoid portion of the internal carotid arteries and the proximal part of the anterior cerebral arteries, and elevation and posterior displacement of both frontopolar arteries. Capillary and venous phase of the carotid angiograms demonstrated an avascular area in the frontal cranial fossa. Branches of the anterior cerebral artery were stretched and displace surrounding the avascular mass. These angiographic findings indicated a huge avascular both frontal lobes posterolaterally. CT scanning revealed a large isodensity mass and the periphery of the mass was enhanced in a ring-like fashion with contrast medium. The mass protruded as a subcutaneous mass through the defect of the frontal bone. The content of the mass was surgically evacuated. The mass was a pyocele containing thick yellowish purulent fluid. It arose from the frontal sinus and extended into the anterior cranial fossa through the destroyed posterior wall of the sinus to separate the falx into two leaves of the dura mater and displace both frontal lobes laterally and posteriorly. Extension of the frontal sinus mucocele and pyocele to the anterior cranial fossa was discussed.