Presentation
Left-sided painless facial swelling.
Patient Data
left-sided expansile multilocular mass lesion within the squamosal portion of the temporal bone with internal fluid-fluid level, narrow zone of transition, no frank aggressive bone destruction or pathologic fracture, no solid enhancing component
Internal fluid-fluid levels are better seen with a pressure effect on the underlying temporal lobe, with no soft tissue extension.
Case Discussion
Initially, the patient was evaluated by ultrasound which unfortunately was reported as a suspisous looking parotid mass and recommended FNA, the result was normal parotid tissue. Eventually, the patient undergo CT and MRI and the possibility of an Aneurysmal bone cyst was raised.
The patient was treated operatively and the finding was confirmed on histology. The lesson is not to recommend a biopsy before knowing the possible nature of the mass and its origin and not to merely rely on the US in the assessment of the deeply seated mass lesions.