鼻咽及鼻窦肌上皮癌的影像学特征

Imaging Features of Myoepithelial Carcinoma in the Nasopharynx and Paranasal Sinus

目的分析鼻咽及鼻窦肌上皮癌的影像学表现,探讨其诊断要点。方法回顾性分析经病理证实的11例鼻咽及鼻窦肌上皮癌的CT、MRI表现及临床资料。其中,4例行CT平扫和MRI平扫、DWI和动态增强扫描;3例仅行MRI平扫、DWI和动态增强扫描;4例仅行CT扫描。结果 11例肿瘤均位于单侧,肿瘤直径均>2.3 cm,形态均不规则,与周围组织分界不清,大多伴有骨质破坏及邻近组织受累。8例CT检查结果示:肿瘤中心位于鼻咽部4例,上颌窦3例,鼻腔及同侧筛窦1例;病灶均呈不规则软组织密度肿块影;5例有明显周围骨质破坏,2例伴颈部淋巴结转移。行增强扫描的1例呈轻度强化。7例MRI检查结果示:肿瘤中心位于鼻咽部5例,上颌窦、筛窦各1例;在T_1WI上,4例呈等信号,3例呈低信号;在T_2WI上,7例均呈稍高或高信号,信号混杂。增强扫描示6例呈明显不均匀强化,1例呈明显均匀强化,1例颈部淋巴结环形强化。肿瘤的平均ADC值为(0.87±0.04)×10^(-3)mm^2/s。结论 CT和MRI能很好地显示鼻咽及鼻窦肌上皮癌的大小、部位、周围骨质破坏情况及与邻近组织的关系,CT示肿瘤邻近骨质易发生溶骨性破坏,MRI表现及ADC值也具有一定的特征性,有助于临床早期诊断及治疗方案的制定。

Objective To analyze the imaging features of myoepithelial carcinoma（ MEC） in the nasopharynx and paranasal sinus and explore its diagnostic points. Methods 11 patients with MEC in the nasopharynx and paranasal sinus confirmed by pathology were analyzed retrospectively. 4 patients underwent plain CT scan,routine MR scan,DWI and DCEMRI. 3 patients underwent routine MR scan,DWI and DCE-MRI. 4 patients underwent CT scan. Results 11 cases had one lesion bilaterally,irregular shape and unclear boundaries. The diameter of the tumors was larger than 2. 3 cm. The aggressive nature of the tumors was demonstrated by bone destruction and invasion of adjacent structures. Among 8 patients who underwent CT examination,tumor centers were located in the nasopharynx in 4 cases,3 in the maxillary sinus,1 in the nasal cavity and ethmoid sinus. 8 cases were of soft tissue density. 5 lesions demonstrated destruction of the adjacent bony structures. 2 cases had cervical lymph node metastasis. 1 lesion showed slight enhancement. Among 8 patients who underwent MRI examination,tumor centers were located in the nasopharynx in 5 cases,1 in maxillary sinus and 1 in ethmoid sinus. On T1 WI,4 showed isointensity and 3 showed hypointensity. On T2 WI,7 showed sligthly high or high signal. After contrast agent injection,6 patients showed obvious heterogeneous enhancement,1 showed obvious homogeneous enhancement and 1 with circular enhancement of cervical lymph node. The mean ADC value was（ 0. 87 ± 0. 04） × 10-3mm2/ s.Conclusion CT and MRI appearances can show tumor size,location,and delineate the relationship of the 1esions with the surrounding tissue. MEC in the nasopharynx and paranasal sinus has osteolytic destruction on CT and owns certain characteristic features on MR and ADC value. These features are helpful to the clinical diagnosis and the treatment plan formulation.