上皮源性腮腺恶性肿瘤的CT征象与病理对照研究

背景与目的:上皮源性腮腺恶性肿瘤种类繁多,CT为腮腺占位的常用影像学检查方法,本研究旨在通过回顾性分析上皮源性恶性肿瘤的CT征象,探讨CT在上皮源性腮腺恶性肿瘤的诊断价值.方法:对经病理确诊的29例上皮源性腮腺恶性肿瘤的CT征象,包括病灶的部位、形态、边界、强化程度、均匀性、邻近组织的浸润、淋巴结转移等进行回顾性分析,并与病理进行对照研究.结果:(1)腮腺低度恶性肿瘤组:共8例,4例为高分化粘液表皮样癌、3例为腺泡细胞癌、1例为上皮-肌上皮癌;3例病灶边缘清楚,3例病灶边缘部分欠清,2例病灶边缘不清;5例病灶形态规则,3例病灶形态不规则;8例病灶均呈明显强化,2例病灶内密度均匀,6例病灶内可见低密度区;所有的病灶均未见侵犯邻近肌群的CT征象,有3例出现淋巴结转移征象.(2)腮腺中高度恶性肿瘤组:共21例,5例为低分化鳞癌、8例为恶性混合瘤、2例为腺癌、1例为淋巴上皮癌、4例为粘液表皮样癌、1例为腺样囊性癌;5例病灶边缘清楚,7例病灶边缘部分欠清,9例病灶边缘不清;10例病灶形态规则,1l例病灶形态不规则;17例病灶呈明显强化,4例恶性混合瘤病灶呈轻度强化;9例病灶内密度均匀,12例病灶内可见低密度区;8例病灶侵犯邻近肌群,8例病灶与腮腺床的脂肪间隙消失,6例出现淋巴结转移征象.结论:上皮源性腮腺恶性肿瘤的CT征象在一定程度上和肿瘤的恶性程度存在相关性,但是,还须结合肿瘤的大小、肿瘤的病理组织学类型才能做出更精确的影像学诊断.

Malignant epithelial parotid tumors: CT imaging and histopathologic correlation

BACKGROUND & OBJECTIVE: Malignant epithelial parotid tumors have various histopathologic types. Computed tomography (CT) has been widely used to detect parotid masses. This study was to analyze CT features of malignant epithelial parotid tumors to evaluate the diagnostic value of CT in the characterization of malignant epithelial parotid tumors. METHODS: CT reports of 29 patients with malignant epithelial parotid tumors (8 at low grade and 21 at intermediate or high grade), confirmed by histopathology in Cancer Center of Sun Yat-sen University, were reviewed. The localization, contour, margin, enhancing type, homogeneity, infiltration into the adjacent structures, and lymph node metastasis detected by CT scan were compared with relevant pathologic results. RESULTS: Of the 8 cases at low grade, 4 were well-differentiated mucoepidermoid carcinoma, 3 were acinic cell carcinoma, and 1 was epithelial-myoepithelial carcinoma; 3 had sharp margin, 3 had partly unsharp margin, and 2 had unsharp margin; 5 had regular contour, and 3 had irregular contour; all were enhanced obviously; 2 showed homogeneous appearance, and 6 showed inhomogeneous appearance with low-density areas; none had adjacent infiltration; 3 had lymph node metastasis. Of the 21 cases at intermediate or high grade, 5 were poorly-differentiated squamous cell carcinoma, 8 were malignant pleomorphic adenoma, 2 were adenocarcinoma, 1 was lymph-epithelial carcinoma, 4 were mucoepidermoid carcinoma, and 1 was adenoidcystic carcinoma; 5 had sharp margin, 7 had partly unsharp margin, and 9 had unsharp margin; 10 had regular contour, and 11 had irregular contour; 17 were enhanced obviously, and the 4 cases of malignant pleomorphic adenoma were enhanced slightly; 9 showed homogeneous appearance, and 12 showed inhomogeneous appearance with low-density areas; 8 had adjacent infiltration (the fat space between tumor and the parotid bed disappeared); 6 had lymph node metastasis. CONCLUSIONS: To some extent, CT features of malignant epithelial parotid tumors are correlated to the differentiation of tumor cells. Moreover, tumor size and histologic subtype should be considered to make a more accurate imaging diagnosis.