肝血管平滑肌脂肪瘤的MRI及临床病理特征

目的探讨肝血管平滑肌脂肪瘤(hepatic angiomyolipoma,HAML)的MRI表现及临床病理特征。方法回顾性分析经病理证实的9例HAML的MRI特征及临床表现。结果 9例均为单发肿块,中位直径4.0 cm(1.4~15.3 cm)。7例无不适症状,2例上腹部不适,均行手术切除,中位随访10个月(2~24个月),无复发。组织学上分为混合型4例和肌瘤型5例。免疫组化均HMB-45(+)、SMA(+)、CD34(+)。5例MRI回波序列见大量脂质成分。增强MRI分两种类型:Ⅰ型,动脉期明显强化,门脉期和延迟期仍强化(混合型和肌瘤型各1例),其对应病理为肿瘤组织含较少血管;Ⅱ型,动脉期强化,门脉期和延迟期消退,其病理为肿瘤富含血管(混合型3例及肌瘤型4例)。结论 HAML临床表现无特异性,HAML的增强MRI特征与肿瘤组织富含血管多少有关。确诊需病理及免疫组化检测HMB-45、SMA、CD34阳性。

MRI imaging and pathological features of hepatic angiomyolipoma

Objective To discuss the main clinical, MRI imaging and pathological features of hepatic angiomyoli- poma （HAML）. Methods The MRI imaging, pathological and clinical features of 9 patients with HAML who under- went surgical resection were retrospectively analyzed. Results All 9 patients had a solitary hepatic mass with mean size of 4.0 cm （range from 1.4 cm to 15.3 cm）. Seven cases were found as incidental liver tumors upon health screening and 2 patients visited hospitals with unspecific symptoms of abdominal discomfort. All the patients underwent liver resec- tion. The median duration of follow-up was 10 months （ranged from 2 months to 24 months）. No recurrence was found. Histologically, 4 cases were conventional mixed type and 5 cases were myomatous predominant. The tumor cells were positive immunostaining for HMB-45, smooth muscle actin （SMA） and CD34. In MRI, dual-echo sequencees of 5 cases showed a large number of lipid. The enhancement pattern of MRI was divided into two types, lesions with abundant cen- tral vessels rapidly decreased （including 1 case of mixed type and 1 case of myomatous predominant） and lesions with small or no vessels demonstrated prolonged enhancement in the portal venous/delayed phase （including 3 cases of mixed type and 4 cases of myomatous predominant）. Conclusion Most HAML patients have no specific clinical manifesta- tions. The enhancement pattern of MRI correlates with abundant or small vessels in tumor. The definite diagnosis of HAML needs to rely on the pathological and immunohistochemistry with the positive of HMB-45, SMA and CD34.