Aggressive osteoblastoma with degeneration to secondary aneurysmal bone cyst

Marcio Luís Duarte,Carlos Alexandre M Pereira,Maria Teresa S Alves,José Luiz M A Prado,Luiz Carlos D Scoppetta

doi:10.5935/1676-2444.20190039

Marcio Luís Duarte, Carlos Alexandre M Pereira + Show 3 more

Open Access

https://doi.org/10.5935/1676-2444.20190039

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Abstract

ABSTRACT A 4-year-old male patient presented with headaches that started 18 months ago and were associated with progressive loss of balance and difficulty walking. Magnetic resonance imaging (MRI) demonstrated an expansile extra-axial mass lesion in the posterior aspect of the posterior fossa on the left, compressing the adjacent brain, as well as the cerebellar hemispheres; it also distorts the fourth ventricle with severe obstructive hydrocephalus upstream. Histological evaluation diagnosed aggressive osteoblastoma with a secondary aneurysmal bone cyst of the skull. We report a case of aggressive osteoblastoma in which the lesion in the MRI was mimicking brain tumor or intracranial primary tumor rather than primary bone tumor.

Highlights

Osteoblastoma is a very rare tumor that constitutes 0.5%-1% of all primary bone tumors(1-7) and 3% of all benign bone tumors, affecting more males (3-2:1 male: female ratio) during the second decade of life(3, 5, 7)
Magnetic resonance imaging (MRI) demonstrated an expansile extra-axial mass lesion in the posterior aspect of the posterior fossa on the left, compressing the adjacent brain, as well as the cerebellar hemispheres; it distorts the fourth ventricle with severe obstructive hydrocephalus upstream
We report a case of aggressive osteoblastoma in which the lesion in the MRI was mimicking brain tumor or intracranial primary tumor rather than primary bone tumor

Summary

Introduction

Osteoblastoma is a very rare tumor that constitutes 0.5%-1% of all primary bone tumors(1-7) and 3% of all benign bone tumors, affecting more males (3-2:1 male: female ratio) during the second decade of life(3, 5, 7). An aneurysmal bone cyst is a rare(6, 8) benign expansile osteolytic lesion with a thin wall, containing blood-filled cystic cavities, but it can be quite destructive locally(2, 6, 8). It impinges significant pressure on the surrounding tissues(8) and its malignant transformation has been reported in 3% of patients(6). MRI: magnetic resonance imaging; FLAIR: fluid attenuated inversion recovery; SPIR: spectral presaturation with inversion recovery

Case report

Aneurysmal bone cyst

Osteoblastoma with secondary aneurysmal bone cyst

Findings

Conclusion