Intraductal carcinoma (IC) is a rare salivary gland tumor with low- to intermediate-grade cytological features. It is further classified into intercalated duct type and apocrine type based on its distinct histologic and immunohistochemical expression. Conventional salivary duct carcinoma (SDC) is an aggressive carcinoma with high-grade features and is usually associated with poor prognosis. In this study, immunohistochemistry and mutation analyses (including HRAS/PIK3CA mutations, RET rearrangement, and human epidermal growth factor receptor 2 [HER2] amplification) of 9 ICs (including 3 pure ICs, 6 ICs with invasive carcinoma) and 24 conventional SDCs were performed and the results were compared. Four intercalated duct-type cases were positive for SOX10 and S100 and negative for AR; five apocrine-type cases showed opposite results. All five apocrine-type cases had cysts with relatively circumscribed tumor borders and morphologically mimicking breast low-grade ductal carcinoma in situ or papillary carcinoma. RET fusion is detected in half of the 4 intercalated duct-type IC but not in the apocrine-type or conventional SDC. HER2 amplification was only observed in conventional SDC. The monoclonal antibody (clone RBT-NRAS) against NRAS Q61R is a sensitive and specific marker used for detecting HRAS Q61R mutation in the salivary gland tumors. The apocrine-type IC had different cytological grades, distinct tumor growth patterns, and no evidence of low- to high-grade transition, suggesting that apocrine-type IC should be distinguished from apocrine SDC with an in situ component.

中文翻译：

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涎腺导管内癌的临床病理研究，重点是顶分泌型。

导管内癌（IC）是一种罕见的唾液腺肿瘤，具有低至中级细胞学特征。根据其独特的组织学和免疫组织化学表达，它可进一步分为插管型和顶分泌型。常规涎腺导管癌（SDC）是一种具有高度特征的侵袭性癌，通常与不良预后相关。在这项研究中，对9个IC（包括3个纯IC，6个具有浸润性癌的IC）和24个常规SDC的免疫组织化学和突变分析（包括HRAS / PIK3CA突变，RET重排和人类表皮生长因子受体2 [HER2]扩增）进行了分析。执行并比较结果。4例插管型病例SOX10和S100阳性，AR阴性。五例高教类型的病例结果相反。所有五种高教分泌型病例的囊肿均具有相对限定的肿瘤边界，并在形态学上模仿乳腺低级导管原位癌或乳头状癌。RET融合在4种插管式IC的一半中被检测到，但在顶泌型或常规SDC中未检测到。仅在常规SDC中观察到HER2扩增。抗NRAS Q61R的单克隆抗体（克隆RBT-NRAS）是用于检测唾液腺肿瘤中HRAS Q61R突变的灵敏且特异的标记物。载脂蛋白型IC具有不同的细胞学分级，明显的肿瘤生长模式，并且没有低至高等级过渡的迹象，这表明载脂蛋白型IC应该与载脂蛋白SDC区别开来。