Objective:

To report a case of poorly differentiated gastric adenocarcinoma diagnosed using Ga-68 FAPI-04 PET/CT after repeated negative biopsies.

Approach:

• Patient Presentation: A 56-year-old man presented with symptoms including abdominal distension, nausea, vomiting, weight loss, and epigastric pain.
• Diagnostic Imaging: F-18 FDG PET/CT showed slightly increased uptake, while Ga-68 FAPI-04 PET/CT demonstrated intense uptake with clearer lesion delineation.
• Surgical Intervention: Distal gastrectomy was performed due to progressive gastric outlet obstruction and persistent suspicion of malignancy.
• Histopathological Analysis: Final histopathology confirmed poorly differentiated gastric adenocarcinoma with partial signet-ring cell morphology.

Key Findings:

• Repeated endoscopic biopsies showed chronic inflammation without malignancy.
• Ga-68 FAPI-04 PET/CT provided higher tumor-to-background contrast compared to F-18 FDG PET/CT.
• Final diagnosis confirmed poorly differentiated gastric adenocarcinoma with partial signet-ring cell morphology.

Interpretation:

Limitations:

• The study is based on a single case report, limiting generalizability.
• No comparative analysis with other imaging modalities was performed.

Conclusion: