Abstract:

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. (Ophthalmol CHN, 2015, 24: 313-316)

Key words: lacrimal sac, malignant tumor, magnetic resonance imaging