泪囊区原发恶性肿瘤的MRI表现及临床病理分析

MRI manifestations and clinical pathological analysis of malignant tumors in lacrimal sac area

目的探讨眼眶泪囊区不同恶性肿瘤的MRI表现与临床病理的关系。设计回顾性病例系列。研究对象北京同仁医院2005-2014年13例经病理证实为泪囊区恶性肿瘤患者的MRI表现及临床资料。方法所有患者均行眼眶MRI平扫及增强检查,其中10例行动态增强扫描,根据时间-信号强度曲线(TIC)分为三种类型(Ⅰ型稳定增强型,Ⅱ型平台型,Ⅲ型流出型)。11例手术切除,2例活检。主要指标MRI表现,强化程度,TIC类型及病变的累及范围。结果病变主体均位于泪囊窝内。病理结果显示淋巴瘤5例、恶性黑色素瘤2例,睑板腺癌、基底细胞癌、基底样鳞状细胞癌、腺样囊性癌、低分化腺癌、皮脂腺癌各1例。MRI表现:淋巴瘤T1WI、T2WI均呈等信号,增强扫描轻度均匀强化。恶性黑色素瘤T1WI呈高信号、T2WI呈低信号,增强扫描轻中度均匀强化。睑板腺癌及低分化腺癌T1WI、T2WI均呈等信号。另4例T1WI呈等信号,T2WI呈略长信号,增强扫描呈轻中度强化。TIC:Ⅰ型、Ⅱ型各2例,Ⅲ型6例。12例病变累及鼻泪管,9例累及邻近皮肤,7例累及眼睑,2例累及眼眶肌锥内间隙。结论泪囊恶性肿瘤因病理类型不同MRI表现不同,常累及邻近结构,MRI可准确显示肿瘤累及范围。TIC三型均有,以流出型为主。

Objectives To investigate MRI characteristic features of malignant tumors in lacrimal sac area. Design Retrospective case series. Participants From 2005 to 2014, MRI findings and clinical data of 13 inpatients with malignant tumors in lacrimal sac area confirmed by pathology in Beijing Tongren Hospital were reviewed. Methods All patients underwent plain and enhanced MRI scan, and ten of them performed dynamic enhanced MRI. Time-signal intensity curve （TIC） was divided into three types （typeⅠ, stability enhancement, typeⅡ platform, and typeⅢ outflow）. Main Outcome Measures T1WI, T2WI, enhanced degree, TIC, and the scope of lesions involving. Results The tumors located in lacrimal fossa, including lymphoma（n=5）, malignant melanoma （n=2）, sebaceous grand carcinoma（n=1）, basal cell carcinoma（n=1）, basal-like squamous cell carcinoma（n=1） adenoid cystic carcinoma （n=1）, low differentiated adenocarcinoma （n=1） and sebaceous carcinoma （n=1）. The MR signal intensity of lymphoma was isointensity to gray matter on T1-weighted and T2-weighted images. Lesions showed mild uniform enhancement on gadolinium-enhanced images. The MR signal intensity of melanoma was hyperintensity on T1-weighted and hypointensity on T2-weighted images. Lesions showed mild to medium uniform enhancement on gadolinium-enhanced images. The MR signal intensity of sebaceous grand carcinoma and low differentiated adenocarcinoma was iso-intensity on T1-weighted and T2-weighted images. The MR signal intensity of other four tumors was iso-intensity on T1-weighted, and mild hyper-intensity on T2-weighted images. The four lesions showed mild to medium enhancement on gadolinium-enhanced images. The enhancement of the adenoid cystic carcinoma was more obviously, otherwise basal cell carcinoma and sebaceous carcinoma less uniform. Two cases showed typeⅠ TIC, including low differentiated adenocarcinoma and adenoid cystic carcinoma. Two cases showed typeⅡ TIC, including malignant melanoma and base cell carcinoma. Six cases showed typeⅢ TIC, including lymphoma （n=4）, meibomian gland carcinoma （n=1） and basal-like squamous cell cacinoma （n=1）. The nasolacrimal duct （n=12）, skin （n=9）, eyelid （n=7） , and the orbital muscle cone gap （n=2） were involved. Conclusions Different MRI features in different pathological types of malignant carcinomas in lacrimal sac area were detected. MRI demonstrated the invading extent accurately. All three types of TIC were seen, with type Ⅲ as the most common one.