18F-FDG PET/CT在CA199升高的黄粒细胞性胆囊炎中的应用：诊断难题与鉴别策略

《Frontiers in Medicine》：18F-FDG PET/CT in xanthogranulomatous cholecystitis with CA199 elevation: diagnostic dilemmas and differentiation strategies

XGC与GBC的影像鉴别诊断及手术策略研究，回顾性分析5例XGC患者，发现FDG-PET/CT及CA19-9均存在假阳性误诊，影像特征与GBC高度重叠，最终依赖病理确诊。提出需发展FLT-PET/CT等先进技术，当前仍建议根治性手术。

　　
Xanthogranulomatous cholecystitis (XGC) is a rare form of chronic gallbladder inflammation characterized by destructive inflammation, intramural nodules, and fibroblastic proliferation. This study analyzed five female patients aged 49–84 years with confirmed XGC diagnoses, treated at Jiangxi Provincial People’s Hospital between 2019 and 2025. All cases were initially misdiagnosed as gallbladder carcinoma (GBC) based on imaging and tumor marker results, highlighting significant diagnostic overlap between the two conditions.

Key findings include:
1. **Imaging Features**: All patients exhibited gallbladder wall thickening (1.2–2.0 cm) with preserved mucosal continuity, a critical distinguishing feature from GBC. Three cases showed intramural nodules and lymphadenopathy, while one patient presented with a concurrent liver abscess and duodenal involvement. FDG-PET/CT scans demonstrated elevated metabolic activity (SUVmax 7.5–19.8), particularly in nodules and thickened walls, but failed to differentiate inflammatory from malignant processes.

2. **Laboratory Findings**: Three patients had elevated CA19-9 levels (433 U/mL, 70.5 U/mL, 362 U/mL), while others showed normal ranges. Inflammatory markers like CRP and WBC were elevated in some cases but not consistently. Postoperative follow-up revealed normalization of CA19-9 within 1–3 months, suggesting its utility as a monitoring tool rather than a diagnostic criterion.

3. **Surgical Outcomes**: All patients underwent radical cholecystectomy with liver resection or lymphadenectomy due to imaging suspicion of GBC. Histopathology confirmed XGC in every case, emphasizing the need for intraoperative frozen sections when malignancy is suspected. Conversion to open surgery occurred in three cases due to severe adhesions and inflammatory infiltration.

4. **Diagnostic Limitations**: Conventional imaging (CT, MRI) and FDG-PET/CT showed overlapping features with GBC, particularly thickened walls, lymphadenopathy, and metabolic activity. The study identified intramural nodules, continuous mucosal lines, and postoperative tumor marker normalization as potential discriminators, though these were insufficient preoperatively.

5. **Clinical Implications**: The study underscores the importance of differentiating XGC from GBC to avoid overtreatment. While radical surgery remains standard for suspected GBC, XGC typically requires less extensive resections. The findings advocate for advanced imaging techniques like FLT-PET/CT to improve diagnostic accuracy, though these remain experimental.

The study concluded that while FDG-PET/CT and conventional imaging provide valuable clues, they are not definitive for XGC. Histopathology remains irreplaceable, and surgical planning should account for imaging ambiguities. Future research should validate FLT-PET/CT and refine imaging protocols for chronic gallbladder inflammation. Clinicians are advised to consider XGC in older female patients with chronic symptoms and壁厚ening, particularly when tumor markers fluctuate postoperatively.