A Rare Adult Presentation of a Calvarial Aneurysmal Bone Cyst
Location
Suwanee, GA
Start Date
17-4-2026 12:00 PM
End Date
17-4-2026 1:00 PM
Description
Adult aneurysmal bone cysts (ABCs) are uncommon, and calvarial involvement is particularly rare. ABCs most often represent secondary lesions arising in association with preexisting osseous abnormalities, including fibrous dysplasia, a combination that is particularly uncommon and may mimic more aggressive disease radiographically. A 35-year-old woman presented with progressively worsening pulsatile pain and a newly detected parietal scalp mass. Computed tomography demonstrated extensive involvement of the left temporal bone and sphenoid wing by fibrous dysplasia, while magnetic resonance imaging revealed a large, multiloculated expansile calvarial lesion with fluid–fluid levels, consistent with a secondary ABC. In the setting of symptom progression, cortical thinning, and interval lesion growth, surgical management was undertaken. The patient underwent image- guidance–assisted resection of the affected calvarium with removal of adjacent dysplastic bone, followed by staged reconstruction using a custom synthetic cranioplasty to restore cranial contour. Histopathologic examination confirmed fibrous dysplasia with superimposed ABC and no evidence of malignancy. The patient recovered without neurologic deficit, and postoperative imaging demonstrated complete lesion excision. Surveillance imaging was planned to monitor for any future changes. To our knowledge, this represents the eleventh reported adult case of an ABC involving the calvarium and underscores the value of integrating clinical, radiologic, and pathologic findings when evaluating expansile cranial lesions.
Embargo Period
5-15-2026
A Rare Adult Presentation of a Calvarial Aneurysmal Bone Cyst
Suwanee, GA
Adult aneurysmal bone cysts (ABCs) are uncommon, and calvarial involvement is particularly rare. ABCs most often represent secondary lesions arising in association with preexisting osseous abnormalities, including fibrous dysplasia, a combination that is particularly uncommon and may mimic more aggressive disease radiographically. A 35-year-old woman presented with progressively worsening pulsatile pain and a newly detected parietal scalp mass. Computed tomography demonstrated extensive involvement of the left temporal bone and sphenoid wing by fibrous dysplasia, while magnetic resonance imaging revealed a large, multiloculated expansile calvarial lesion with fluid–fluid levels, consistent with a secondary ABC. In the setting of symptom progression, cortical thinning, and interval lesion growth, surgical management was undertaken. The patient underwent image- guidance–assisted resection of the affected calvarium with removal of adjacent dysplastic bone, followed by staged reconstruction using a custom synthetic cranioplasty to restore cranial contour. Histopathologic examination confirmed fibrous dysplasia with superimposed ABC and no evidence of malignancy. The patient recovered without neurologic deficit, and postoperative imaging demonstrated complete lesion excision. Surveillance imaging was planned to monitor for any future changes. To our knowledge, this represents the eleventh reported adult case of an ABC involving the calvarium and underscores the value of integrating clinical, radiologic, and pathologic findings when evaluating expansile cranial lesions.