Department of Dermato-Oncology/Dermatology, National Hospital Organization Kagoshima Medical Center, Kagoshima, Japan.
Department of Dermatology, University of Occupational and Environmental Health, Kitakyushu, Japan.
J Cutan Pathol. 2024 Feb;51(2):92-98. doi: 10.1111/cup.14539. Epub 2023 Sep 24.
Apocrine carcinoma cases with sebaceous differentiation have not been reported and can be misdiagnosed as sebaceous carcinoma. We present two cases of apocrine carcinoma with marked sebocyte-like cytological features. Tumors were observed in the left axilla of a 68-year-old man (Case 1) and the right axilla of a 72-year-old man (Case 2). Both patients presented with multiple lymph node metastases. Histopathology revealed densely distributed solid nests of tumor cells containing foamy cytoplasm and enlarged round nuclei with prominent nucleoli. The tumor cells diffusely expressed adipophilin, PRAME (cytoplasmic pattern), androgen receptor, BerEP4, and GCDFP15 but did not express p63 in both cases. PIK3CA E726K and H1047R mutations were detected in Cases 1 and 2, respectively. Tumor location in the axilla, the presence of eosinophilic granular cytoplasm, prominent nucleoli, and PIK3CA mutations, immunoreactivity for BerEP4 and GCDFP15, and lack of p63 immunoexpression findings matched apocrine carcinoma characteristics, but not sebaceous carcinoma. Thus, apocrine carcinoma can demonstrate intracytoplasmic lipid accumulation and rarely exhibit sebocyte-like cytological features. Apocrine carcinoma should be distinguished from sebaceous carcinoma due to the former's higher metastatic potential and lack of association with Muir-Torre syndrome.
具有皮脂分化的大汗腺癌病例尚未报道，可能被误诊为皮脂癌。我们报告了两例具有明显腺泡细胞样细胞学特征的大汗腺癌。肿瘤发生于 1 例 68 岁男性（病例 1）和 1 例 72 岁男性（病例 2）的左侧腋窝和右侧腋窝。两名患者均有多处淋巴结转移。组织病理学显示肿瘤细胞密集分布的实性巢，含有泡沫状细胞质和大而圆的核，核仁明显。肿瘤细胞弥漫性表达脂肪细胞分化因子（adipophilin）、黑色素瘤相关抗原（PRAME，细胞质模式）、雄激素受体、BerEP4 和 GCDFP15，但在两个病例中均不表达 p63。在病例 1 和 2 中分别检测到 PIK3CA E726K 和 H1047R 突变。肿瘤位于腋窝、存在嗜酸性颗粒细胞质、明显核仁、PIK3CA 突变、BerEP4 和 GCDFP15 免疫反应性以及缺乏 p63 免疫表达的发现符合大汗腺癌的特征，但不符合皮脂癌。因此，大汗腺癌可能表现为细胞内脂质堆积，很少表现出腺泡细胞样细胞学特征。由于前者具有更高的转移潜能且与 Muir-Torre 综合征无关，因此应将大汗腺癌与皮脂癌区分开来。
