兔肺隐球菌病的CT表现和病理对照

CT and pathological study of rabbit pulmonary cryptococcosis

目的构建新西兰大白兔肺隐球菌病模型,观察其CT表现,并分析其与病理结果的关系。方法新西兰大白兔20只,第1～5天每日静脉注射阿糖胞苷440mg/m2,6天后隔日注射;第4日起应用万古霉素、头孢他定及庆大霉素静脉注射;第6日经皮气管穿刺接种新生隐球菌菌悬液0.4～0.8ml。接种后隔日行CT检查,观察并记录兔的死亡时间。第10、11天处死所有实验兔,取病变肺组织病理切片观察及真菌培养。结果14只实验兔成功建立肺隐球菌病状态,其中13只CT表现为单发或多发实变,1只表现为多发的结节和实变灶;组织病理检查可见间质细胞增生,炎细胞浸润(14只);肺泡渗出,间质充血(10只);出血性坏死(5只);还可见玻璃样变(1只);3只见肉芽肿形成,5只病灶肺间质、细支气管和肺泡腔内可见隐球菌。结论兔肺隐球菌病CT表现多为位于肺野外周部的多发实变,病理上以炎细胞浸润,肺泡渗出为主,直接观察到隐球菌孢子可以确诊。

Objective To analyze the CT appearances and pathological findings of pulmonary cryptococcosis in rabbits. Methods Cytarabine was injected every day from first to the fifth day and every other day from the sixth day, while Vancomycin and ceftazidime were injected every day and Gentamicin every other day from the forth day in twenty New Zealand rabbits. After that, all the rabbits were inoculated by 0.4--0.8 ml suspension in the sixth day. Chest CT scanning were performed every other day after inoculation. After rabbits died, pathological examination and fungus cultivation were performed. Results Cryptococcus neoformans for cultivation were positive in 18 rabbits. Lung lesions were displayed in 14 rabbits. Lesions in 13 rabbits were multiple and distributed in peripheral field. There were multiple nodules and consolidation on every lobe of right lung in the rest rabbits. Histopathological findings included interstitial cell hyperplasia, inflammatory cell infiltration （14）, lung alveolus exudation, interstitial substance congestion （10）, hemorrhagic necrosis （5）, hyalinization （1） and granuloma formation （3）. Cryptococcus spore were found in interstitial substance or lung alveolus in 5 rabbits. Conclusion The main CT findings of pulmonary cryptococcosis in New Zealand Rabbits is consolidation, and the lesions often distribute in peripheral lung field. The main histopathological findings include inflammatory cell infiltration and lung alveolus exudation. Detection of cryptococcus spore is evidence of final diagnosis.