The Sunburst Sign in the Mesentery: Unveiling the Diagnosis With ⁶⁸Ga DOTATATE PET/CT.

Contrast-enhanced abdominal CT of a 57-year-old man presenting with abdominal pain and diarrhea revealed a spiculated, calcified mesenteric mass, initially suggesting a desmoid tumor (DT). The lesion's ametabolic nature on 18 F-FDG PET/CT supported this suspicion. However, ⁶⁸Ga DOTATATE PET/CT demonstrated intense uptake in both the mesenteric mass, which exhibited a "sunburst" calcification pattern, and the primary ileal focus. Histopathology confirmed an ileal neuroendocrine tumor (NET) with mesenteric lymph node metastasis. This case highlights the critical role of ⁶⁸Ga DOTATATE PET/CT in the differential diagnosis, primary site detection, and accurate staging of FDG-negative mesenteric masses associated with a desmoplastic reaction.