Cranioorbital fibrous dysplasia: with emphasis on visual impairment and current surgical management

Abstract

<jats:p>Fibrous dysplasia is a benign but slowly progressive disorder of bone in which normal cancellous bone is replaced by immature woven bone and fibrous tissue. Significant deformity and both acute and chronic visual impairment can result. A contemporary understanding of fibrous dysplasia, emphasizing the origins of visual impairment, indications for decompressive surgery, and the techniques for correction of the cosmetic deformity are presented.</jats:p> <jats:p>In their experience and review of the literature, the authors found the most frequent clinical presentations to be exophthalmos, displacement of the globe, abnormalities of extraocular motility, cosmetic deformity, and visual impairment. Although traditionally the cause of visual impairment has been ascribed to impingement of the optic canal on the optic nerve, the authors' experience is that the most common cause of visual loss is cystic degeneration of the tumor, particularly with those involving the anterior clinoid process. Exophthalmos and optic canal stenosis are less common causes of visual impairment. Indications for surgical intervention include acute and/or serially radiographically documented and relentless visual impairment and significant cosmetic deformity. Individualized management strategies are also discussed.</jats:p>

An alternative management approach to paranasal sinus fibro‐osseous lesions

“…7,8 Conservative management with serial scans and observation for FD patients with minimal symptoms or cosmetic deformity is generally recommended. 20 The results from our study support a conservative role in adult FD, as the majority are incidental and asymptomatic, with only 1 case exhibiting evidence of interval growth over a mean period of 42.2 months. The rate of malignant transformation to an osteosarcoma is low, at 0.5%, but this possibility needs to be considered in any patient with a rapid increase in size or pain.…”

“…3,17 Surgery to resect FD is indicated in cases of significant cosmetic deformity or complications such as visual compromise. 20,22 Extensive lesions involving the skull base and orbit require a craniofacial resection with appropriate reconstruction. 22 Complete resection of FD lesions in the paranasal sinuses with extensive involvement can be difficult to achieve due to the unacceptable morbidity from surgery and its tendency to merge imperceptibly with surrounding normal bone.…”

“Well Digging” Subcraniotomy Strategy with Navigation for Optic Nerve Decompression in Frontoorbital Fibrous Dysplasia: Preliminary Experience

“…Visual loss also represents the most common neurological complication of FD affecting the skull. 1,11 It is noteworthy that the optic nerve comprises 5 major units: chiasmatic, intracranial, intracanal, intraorbital, and intraocular parts. 12 It is the intracanal unit optic nerve decompression that has received considerable attention.…”

“…10 The other is that there is a concern that prophylactic or therapeutic decompression may lead to unnecessary injury to the optic nerve due to direct iatrogenic trauma or loss of blood supply. 11 …”

Fibrous Dysplasia of the Sphenoid Bone: Case Report

“…De kom pres yon cer ra hi si nin ise gör me bo zuk lu ğu ge liş ti ğin de ve be lir gin koz me tik de for mi te var sa ya pıl ma sı ge rek ti ği ni be lirt miş-ler dir. 25 Ben zer ça lış ma lar da da kon ser va tif yak laşım lar sa vu nul muş tur. 2,21,26,27 Da ha az sa yı da ki ça-lış ma da ise cer ra hi nin er ken dö nem de ya pıl ma sı ge rek ti ği be lir til mek te dir.…”