Elevated FAPI Activity in an Adult Brodie Abscess

Area of Science:

• Medical Imaging
• Oncology
• Orthopedics

Background:

• Brodie abscess is a subacute osteomyelitis typically presenting with vague symptoms.
• Osteolytic lesions can be challenging to differentiate from bone metastases using conventional imaging.
• Fibroblast activating protein inhibitor (FAPI) imaging is emerging for various pathologies.

Purpose of the Study:

• To report a case of Brodie abscess mimicking bone metastasis.
• To highlight the utility of 18F-FDG and 68Ga-FAPI PET/CT in diagnosing challenging osteolytic lesions.
• To emphasize the importance of including Brodie abscess in the differential diagnosis.

Main Methods:

• Case report of an adult patient with an osteolytic lesion.
• Utilized 18F-FDG PET/CT and 68Ga-FAPI PET/CT for diagnostic imaging.
• Compared imaging findings with histopathological results.

Main Results:

• The Brodie abscess demonstrated elevated uptake of both 18F-FDG and 68Ga-FAPI.
• The imaging findings mimicked those of bone metastasis.
• Histopathology confirmed Brodie abscess.

Conclusions:

• Brodie abscess can present with imaging characteristics similar to bone metastases.
• 68Ga-FAPI PET/CT may show increased uptake in Brodie abscess, aiding in differential diagnosis.
• Consider Brodie abscess in the differential diagnosis of osteolytic lesions with increased 68Ga-FAPI uptake.