RÉSUMÉ
Objective:To explore the CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma (FDCS) of the spleen.Methods:The clinical data of 12 patients with splenic inflammatory pseudotumor like FDCS admitted to 3 central hospitals including Yongjia People's Hospital in Zhejiang Province from January 2015 to December 2022 were retrospectively analyzed, including 4 males and 8 females, with a median age of 60 years old. The number, shape, size and CT features of the lesions were analyzed based on patient's CT image data.Results:CT scans of 12 patients showed 15 lesions, including 10 single lesions and 2 multiple lesions. The lesions were circular in 5 cases, elliptical in 4 cases, and irregular in 3 cases. The median maximum diameter of the mass is 6.5 cm. On plain scan, all 12 tumors showed low density or slightly low density. The CT value is (41.3±7.2) HU; 8 cases had uneven density and 4 cases had uniform density. There were 8 cases with clear tumor boundaries and 4 cases with unclear boundaries. There were 8 cases with tumor necrosis and cystic transformation, and 5 cases showed patchy bleeding lesions in the center of the tumor. Enhancement: the arterial phase shows small patches or flocculent enhancement at the edges or parenchymal parts of the tumor, with CT value of (56.0±3.8) HU. Among them, there were 7 cases of mild enhancement, 4 cases of moderate enhancement, and 1 case of significant enhancement. During the portal phase, there was mild to moderate persistent small patchy uneven enhancement, with CT value of (62.0±4.3) HU. Among them, there were 8 cases of mild enhancement and 4 cases of moderate enhancement. The delayed phase showed a slow withdrawal of enhancement, with CT value of (45.0±8.2) HU. All 12 cases underwent complete resection and were diagnosed with FDCS through pathological examination.Conclusion:FDCS plain scan shows circular or elliptical uneven low-density masses, with small patches or flocculent light to moderate uneven enhancement in the arterial phase, continuous enhancement in the portal phase, and slow withdrawal in the delayed phase as the main characteristics.