Division of Dermatology and Dermatopathology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan; and.
Division of Dermatology, Nippon Medical School, Tokyo, Japan.
Am J Dermatopathol. 2024 Aug 1;46(8):471-482. doi: 10.1097/DAD.0000000000002600. Epub 2023 Dec 13.
Mixed tumor of the skin (MTS) is a tumor characterized by folliculosebaceous-apocrine differentiation. Because of the wide range of histological variations, understanding the unique features of MTS can help improve diagnosis. This study describes the histopathological characteristics of MTS, mainly apocrine-type MTS (AMT), using 166 cases of AMT. We found that nodular aggregates of myoepithelial cells, mucinous changes in the stroma, and follicular differentiation were standard characteristic features of MTS. Among the cases studied, 67% showed prominent follicular germinative cells and 40% showed prominent lipomatous metaplasia in the stroma. These cases often pose difficulties for the diagnosis of AMT because of insufficient evidence of sweat glands or myoepithelial cell differentiation. This is the first study to examine how the histological features of AMT change as the tumor extends deeper into the dermis. We found that the proportion of AMT with folliculosebaceous differentiation and large lumina increased as it got deeper into the dermis. Histopathological diagnosis of MTS is vital because the clinical symptoms lack specificity. This study enhances our understanding of the histopathological characteristics of MTS.
皮肤混合瘤（MTS）是一种具有毛囊皮脂腺-顶泌汗腺分化特征的肿瘤。由于组织学变异范围广泛，了解 MTS 的独特特征有助于提高诊断水平。本研究使用 166 例 AMT 描述了 MTS 的组织病理学特征，主要是顶泌汗腺型 MTS（AMT）。我们发现，肌上皮细胞的结节状聚集、基质中的黏液样变化和滤泡分化是 MTS 的标准特征。在研究的病例中，67%的病例显示出明显的滤泡生发细胞，40%的病例显示出明显的脂肪化生。这些病例由于汗腺或肌上皮细胞分化的证据不足，常常给 AMT 的诊断带来困难。这是首次研究 AMT 的组织学特征随肿瘤向真皮深部延伸而发生的变化。我们发现，随着向真皮深部延伸，具有毛囊皮脂腺分化和大腔的 AMT 的比例增加。MTS 的组织病理学诊断至关重要，因为其临床症状缺乏特异性。本研究增强了我们对 MTS 组织病理学特征的理解。
