涎腺病理

小涎腺肿瘤病理诊断
解放军总医院病理科 石怀银
小涎腺肿瘤活检病理诊断 涎腺肿瘤的组织学分级
口腔是小涎腺肿瘤最多见部位，但由于活检组
织较少，一般观察不到边界情况，给病理诊断带 来困难。
口腔常见良性肿瘤包括多形性腺瘤、基底细胞腺
瘤；恶性肿瘤包括腺样囊性癌、多形性低度恶性 腺癌，粘表等。
在上述肿瘤中，除粘表外，其他肿瘤在组织学形
特殊染色及免疫组化
特殊染色对肿瘤鉴别诊断帮助不大。肿瘤均有
细胞外粘液阳性物质，但胞浆粘液染色阴性。多 数肿瘤均含有细胞内糖原。 大部分肿瘤均含有上皮和肌上皮成分，因此免 疫组化染色帮助不大。上皮成分表达广谱CK、 低分子量CK如CK7和CAM52，CEA, EMA；而 肌上皮表达广谱CK, Vimentin, P63, Calponin, SMA, S100,GFAP等。 有文献报道CD117，SMA, KI67在腺样囊性癌 中明显高于多形性低度恶性腺癌。但也有文献报 道CD117也表达于多形性腺瘤和基底细胞腺瘤。
态上有重叠，包括均无包膜、多种组织学结构、 细胞异型性小、含有上皮和肌上皮成分、分裂相 少见等。
免疫组化染色特点也有重叠。
小涎腺肿瘤的边界、包膜和浸润情况
良性或恶性口腔小涎腺肿瘤均无包膜。 良性或恶性口腔小涎腺肿瘤均可表现为边界清楚
，但恶性肿瘤表现为浸润性生长，比如累及周围正 常组织、神经、血管等。 见到明确的浸润可以诊断为恶性，但小活检或穿 刺活检往往仅包含肿瘤成分，难以观察到边界。
CK
S100
CK
P63
S100
VIM
CD117
穿刺活检标本判断良恶性困难的原因：
穿刺组织局限，难以评估浸润情况 代表恶性的形态学特征如多形性、异常核分裂相、坏
死、转移等学有交叉，如基底细胞腺瘤和基底细
胞腺癌；多形性腺瘤和多形性低度恶性腺癌等。
周围细胞的栅栏样排列多见于基底细胞肿瘤，但
也不是诊断该病的特异性形态特征。
多形性低度恶性腺癌常常见到周围细胞的漩涡状
排列，也可以见到肿瘤细胞的列兵样排列，还可 以看到正常粘液性涎腺腺泡裹挟于肿瘤内，但都 不是特异的形态学特点。
小涎腺肿瘤细胞形态学特点
肿瘤细胞异型性通常不明显，分裂相少见，
肿瘤间质
软骨粘液样基质支持多形性腺瘤诊断。 软骨粘液样间质由肌上皮产生，可见基质内肌
上皮融入现象。 多形性低度恶性腺癌可以见到浅蓝色粘液透明 样基质；腺样囊性癌可见充满嗜碱性或嗜酸性物 质的假腔。 透明变性胶原间质多见于基底细胞腺瘤，尤其 是膜型。还可以见到分布于肿瘤细胞中的胶原小 球。
很少有坏死。 腺样囊性癌细胞核浆比大，基底样，有角， 核仁不明显。但这种核形也可见于基底细胞肿 瘤甚至多形性腺瘤。 多形性低度恶性腺癌细胞核常常空泡状，常 常可见小核仁。 鳞化多见于基底细胞腺瘤，尤其是膜型；但 多形性腺瘤和多形性低度恶性腺癌也可出现鳞 化。腺样囊性癌鳞化很少见。 透明细胞和嗜酸性细胞可见于多种肿瘤内。
Acinic cell carcinoma
Acinic
Cell Carcinoma was described by Nasse in 1892 as a benign tumor; it was only in 1953 that its malignant potential was realized with the description of 5 aggressive cases by Buxton et al.
小唾液腺肿瘤内上皮细胞成分
肿瘤性上皮细胞呈柱状、立方或扁平状。 可以形成管状、囊状或实性细胞巢结构。 管腔内可以看到PAS阳性的粘液样物质。 基底细胞腺瘤、腺样囊性癌以基底样细胞为主
，但也可以看到多少不等的管腔，而且有些亚型 如管状型基底细胞腺瘤以管腔结构为主。
上皮细胞可以发生鳞化、嗜酸性化生、透明细
AciCC
is generally has a favorable prognosis. According to a National Cancer Database review (1985 to 1995), the 5-year disease-specific survival for AciCC was shown to be 91%
The
current WHO classification refers to ACC tumors by predominant pattern rather than actually assigning a numeric grade.
ACC
with high-grade transformation (ACC-HGT) is a rare, highly aggressive variant of ACC characterized by areas of pleomorphic mitotically active high-grade carcinoma. Conventional ACC is a biphasic tumor with ducts and myoepithelial myoepithelial cells, but the transformed component in ACC-HGT is purely of a ductal phenotype with a solid or cribriform appearance. Transformed components show prominent nuclear size and chromatin variability. Common features include fibrocellular desmoplasia, abundant mitoses, necrosis, and microcalcifications. Unique patterns in HGT include micropapillary and squamoid growth.
腺样囊性癌
5-year
survival is favorable at roughly 75% to 80%, but 15year survival is poor at about 35%. cytomorphologically bland and monomorphic, yet among the most infiltrative of carcinomas. ACC does not seem to have much risk of lymphatic spread as regional lymph nodes are involved in only about 5% of case. Thus, many institutions may not perform neck dissections routinely on ACC patients.
Carcinoma
ex pleomorphic adenoma (CAxPA) comprises 10% to 15% of all salivary gland malignancies. the carcinomatous components are typically high grade or of an aggressive histologic type, with high-grade adenocarcinoma, not otherwise specified, and salivary duct carcinoma being the most common histologic subtypes. However, as many as 15% of tumors are low grade and may behave in a more indolent manner with regard to histologic subtype, a myoepithelial carcinomatous component has been correlated in a recent study with more aggressive behavior. As such, the carcinomatous component should be characterized as to type and grade. A rough quantitation of the carcinomatous component is recommended.
与预后关系最密切。
粘液表皮样癌
粘液表皮样癌的组织学分级系统包
括AFIP、Brandwein、和修订的Healey 系统。
Brandwein系统：
在一些预后不良相关指标中（边界侵袭、实性
巢状生长、神经累及等），如果一项都没有，属 于low grade, 如果有一项不利指标，属于 intermediate grade，2项以上属于high grade。
Intracapsular
CAxPA describes a carcinomatous component that is confined to within a pleomorphic adenoma, whereas minimally invasive CAxPA describes a tumor with minimal extent beyond the capsule The WHO definition for minimal invasion is less than 1.5mm of invasion beyond the capsule. Both these subgroups are considered indolent variants that should not be considered equivalent to the typical CAxPA. Katabi et al indicated as many as 25% of their intracapsular or minimally invasive CAxPA behaved in an aggressive fashion.