Aneurysmal bone cyst on top of fibro-osseous lesion of the ethmoid sinus with orbital and intracranial extension in a child

Abstract

Objective: Aneurysmal bone cysts (ABCs) rarely involve the cranium. We report a case arising in the ethmoid sinus with orbital and intracranial invasion. Imaging suggested an associated fibro-osseous lesion. The lesion was completely resected. Histology confirmed the imaging diagnosis of ABC on top of an ossifying fibroma. A multi-disciplinary approach is essential for optimal surgical outcomes. Methods: We report a case of an 8-year-old boy with a 5 week history of painless, increasing prominence of the left eye. Clinical examination revealed non-pulsatile left proptosis. Visual acuity and ocular movements were normal. CT and MRI scans of the maxillofacial regions showed a large space-occupying lesion involving the left ethmoid air cells with left orbital and left inferior frontal intracranial extension. Multiple fluid levels with blood products were seen. Areas of the bony component of the lesion showed ground glass density on CT. Imaging was consistent with an aneurysmal bone cyst with an underlying fibro-osseous lesion; probably fibrous dysplasia which was confirmed after surgical removal of the lesion. A multi disciplinary team of maxillo-facial, neurosusugery and ENT surgeons performed the surgery. Results: Aneurysmal bone cyst arising from an osseous fibroma of the skull is rare. Total resection can be achieved with a multi-disciplinary surgical approach. Post-operative histology confirmed by the imaging findings.

Isolated calvarial aneurysmal bone cyst in a pediatric patient: illustrative case

“…Approximately 30% of calvarial ABCs have been reported to occur in conjunction with associated pathology (secondary ABC), including osteoblastoma, chondroblastoma, giant cell tumors, osteogenic sarcoma, chondromyxoid fibroma, Langerhans cell histiocytosis, or fibrous dysplasia. 3,4,[9][10][11][12][13][14][15] Although primary ABCs are benign tumors of the bone, they can destroy surrounding bone tissue and enlarge rapidly, as in our illustrative case. ABCs of the skull present with varying symptoms depending on their anatomical location; an enlarging palpable mass, focal tenderness, headache, 3 cranial nerve palsy, 16 seizure, 17 otitis media, 18 vision changes, 19 ptosis or exophthalmos, 18 cerebellar signs, 20 bacterial meningitis, 21 or increased intracranial pressure and hydrocephalus [22][23][24] have all been reported in the literature.…”