[No-malignant lessions involving the paranasal sinuses and anterior skull base]

The lesions that involve the paranasal sinuses and the anterior cranial base at the same time are not unusual. These diseases have different features. The aim of this study is to set out the particularities of the non-malignant lesions involving both zones.

Retrospective study of 32 patients between 1986 and 2007 diagnosed with: non-malignant tumours (31.2 %), tumorlike lesions (3.1 %), fibrous-osseous lesions (12.5 %), congenital or acquired malformations (18.7 %) and infection disease (34.3 %). We analyse the diagnostic imaging, the treatment and pathogen mechanism.

Only 6 of 43 osteomas involved the paranasal sinuses and anterior cranial fossa (13.04 %): 3 cases have developed meningitis and 1 developed a pneumocephalus. 2 cases are meningiomas: 1 was asymptomatic and the other one caused destruction at subtotal frontal bone. 1 giant hemangioma associated with Klippel-Trenaunay syndrome is treated by combined craniofacial approach. The fibrous-osseous lesions were specifically fibrous dysplasia and affected the ethmoides. The encephalocele were predominating in the malformations group, 2 were diagnosed after repeated meningitis. 11 cases are included by infection: 10 cases caused osteomielitis and the eleventh is a patient with a mucormycosis. Surgery has been used in 84.3 % of the cases: frontal craniotomy 37 %, combined craniofacial approach 18.5 %, subfrontal approach 18.5 %, osteoplastic technique 18.5 %, lateronasal approach 3.7 %, endonasal microscopic resection 3.7 %.

In this study the diagnosis, extension and surgical management were supported in the imaging. A closed separation between the anterior cranial fossa ant the sinus is necessary after the resection. The reconstruction was performed using a pedicled pericranial flap and titanium mesh in most of the cases.