PET-Negative Gastrointestinal Stromal Tumors
A 66-year-old woman presented with epigastric and right-sided chest pain. Endoscopy discovered a submucosal mass in the antrum. Percutaneous biopsy revealed a GIST. A subsequent PET/CT (fig. ) showed a 4-cm paragastric tumor, with a locoregional suspicious lymph node of 6 mm in diameter. There was no evidence of other metastasis. The tumor was FDG negative, except for a central area of the tumor with a maximum SUV of 4.2.\nThe patient initially refused the intended surgery because of fear of perioperative risks due to other medical conditions. She received palliative therapy with imatinib. After 3 months, PET/CT showed a slightly larger tumor with a lower FDG uptake with a SUV of maximum 3.0. Consequently, the patient agreed to be operated on. A distal gastrectomy was performed. Histology revealed a typical GIST of 7 cm in diameter with a mitotic count of <5/50 HPF. Because of the low-risk profile (low mitotic count, location of the tumor), the patient received no adjuvant therapy with imatinib. So far, there has been no evidence of tumor recurrence.