Incidental Detection of Femoral Pseudoaneurysm at 18F-FDG PET/CT

Area of Science:

• Oncology
• Vascular Surgery
• Radiology

Background:

• Patients with a history of cancer, such as lung cancer and melanoma, require careful monitoring for potential recurrence or new pathologies.
• 18F-FDG PET/CT is a valuable imaging modality for detecting metabolically active lesions, often used in cancer follow-up.

Purpose of the Study:

• To report a case where a new mass identified on 18F-FDG PET/CT in a cancer patient was ultimately diagnosed as a vascular anomaly.
• To highlight the importance of integrating different imaging modalities for accurate diagnosis.

Main Methods:

• A 72-year-old male patient with a history of lung cancer and melanoma underwent routine follow-up using 18F-FDG PET/CT.
• Computed tomography (CT) revealed a new right groin mass with mild fluorodeoxyglucose (FDG) uptake.
• Ultrasound with Doppler was performed to further characterize the lesion.

Main Results:

• The CT component of the 18F-FDG PET/CT demonstrated a new mass in the right groin.
• Mild FDG activity was noted within the mass on the PET images.
• Ultrasound confirmed the presence of flow within the lesion, identifying it as a pseudoaneurysm of the right femoral artery.

Conclusions:

• A new focal uptake on 18F-FDG PET/CT in a cancer patient does not always indicate malignancy.
• Vascular abnormalities, such as pseudoaneurysms, can mimic malignant lesions on PET/CT.
• Ultrasound is crucial for differentiating vascular lesions from true neoplastic processes.