Ossifying fibromas of the paranasal sinuses: diagnosis and management.

Fibro-osseous benign lesions rarely affect the sinonasal tract and are divided into 3 different entities, namely osteoma, fibrous dysplasia and ossifying fibroma. They share several clinical, radiological and histological similarities, but have different behaviours. Ossifying fibroma, and in particular the "juvenile" histological subtype, may have a locally aggressive evolution and a high risk for recurrence if removal is incomplete. The purpose of the present study is to compare the clinical behaviour of ossifying fibroma with the other benign fibro-osseous lesions; highlight different behaviour between the histological subtypes; compare the advantages, limitations and outcomes of an endoscopic endonasal approach with reports in the literature. We retrospectively reviewed 11 patients treated for sinonasal ossifying fibroma at a tertiary care centre. All patients underwent CT scan, and MRI was performed in cases of cranial base involvement or recurrence. Pre-operative biopsy was performed in cases where it was possible to use an endoscopic approach. One patient underwent pre-operative embolisation with ipsilateral visual loss after the procedure. Depending on its location, removal of the tumour was performed using an endoscopic (n = 7), or an external (n = 3) or combined (n = 1) approach. Histopathologically, 5 patients presented the conventional type, 5 the juvenile psammomatoid variant, which was associated in 1 case with an aneurismal bone cyst, and 1 case presented the trabecular juvenile variant. Three patients affected by the juvenile psammomatoid histological variant presented invasion of the skull base and underwent a subtotal removal that subsequently required, due to the regrowth of the remnant, a transbasal approach. Clinical, radiological and histological findings should all be considered to establish differential diagnosis among fibrous osseous lesions. More studies are necessary to conclude if the localisation and extension of the disease at the time of diagnosis is more important than the histological variant. An endoscopic approach is the first choice in most of cases even if an external open approach may be necessary in selected patients.

Unilateral vestibular schwannoma associated with a Jacobson's schwannoma.

Coexistence of unilateral vestibular schwannoma and Jacobson's schwannoma growing in the same intracranial site is rarely observed. We present the case of 36-year-old woman with primary diagnosis of vestibular schwannoma and subsequent appearance of schwannoma to the Jacobson's nerve. Initial wait and see strategy was performed offered us the opportunity to describe Jacobson's lesion features at computed tomography over a period of 4 years. Subtotal petrosectomy with infralabyrinthine approach was subsequently executed to remove the growing mass of the temporal bone. The Jacobson's schwannoma increased its size from 0.4 cm for years whereas vestibular schwannoma size was unchanged after 7 years observation. The concomitant removal of both schwannomas is still associated with the size of the CPA lesion and to patient's symptoms.