False-Positive FAPI Expression in Benign Breast Adenosis.

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• Breast adenosis is a benign condition that can mimic malignant lesions on imaging.
• Fibroblast activation protein inhibitor (FAPI) is expressed in various lesions, potentially leading to false positives.
• Accurate differentiation of benign from malignant breast lesions is critical for patient management.

Purpose of the Study:

• To report a case of FAPI-avid benign breast adenosis.
• To discuss the diagnostic challenges posed by imaging similarities between adenosis and breast cancer.
• To highlight the implications of FAPI expression in benign conditions for diagnostic accuracy.

Main Methods:

• Case presentation of a patient with adrenal adenocarcinoma.
• Utilized 68Ga-FAPI-46 PET/CT imaging.
• Histopathological correlation was performed.

Main Results:

• The case demonstrated significant FAPI uptake in benign breast adenosis.
• This uptake mimicked malignant lesions, posing a diagnostic challenge.
• The patient had a co-existing adrenal adenocarcinoma.

Conclusions:

• Benign breast adenosis can exhibit high FAPI avidity.
• FAPI PET/CT interpretation requires careful consideration of benign mimics.
• This case underscores the importance of integrating imaging findings with clinical and pathological data.