Hill-Sachs lesion on FDG PET/CT

Area of Science:

• Oncology
• Radiology
• Orthopedics

Background:

• Colon cancer metastasis typically involves visceral organs or multiple bone sites.
• FDG PET/CT is a standard imaging modality for cancer staging and detection.
• Differentiating benign bone lesions from metastases is crucial for accurate patient management.

Observation:

• A patient with colon cancer presented with an FDG-avid lytic defect in the humeral head on FDG PET/CT.
• No other suspicious metastatic lesions were identified.
• The patient had a history of chronic anterior shoulder dislocations.

Findings:

• The humeral head lesion was diagnosed as a Hill-Sachs lesion, a common injury associated with shoulder dislocations.
• FDG avidity in a Hill-Sachs lesion can mimic malignancy on PET/CT scans.
• This case underscores the potential for benign osseous abnormalities to exhibit increased metabolic activity.

Implications:

• Clinical correlation and patient history are essential for accurate interpretation of FDG PET/CT findings.
• FDG-avid Hill-Sachs lesions can be a diagnostic challenge, requiring careful consideration to avoid misdiagnosis of metastatic disease.
• Radiologists and oncologists should be aware of this imaging pitfall in patients with a history of shoulder instability.