Departments of Pathology, and.
Dermatology, University of Michigan, Ann Arbor, MI.
Am J Dermatopathol. 2022 Nov 1;44(11):855-858. doi: 10.1097/DAD.0000000000002270. Epub 2022 Jul 28.
Microsecretory adenocarcinoma (MSA) of the salivary gland is a new entity recently added to the World Health Organization Classification of Head and Neck Tumors. This tumor is characterized by a recurrent MEF2C-SS18 translocation. We present a nodular tumor confined to the dermis of the ear canal of a 44-year-old patient, which demonstrated classic histopathologic features and molecular alteration of MSA. Specifically, the tumor was composed of numerous tubules and microcysts filled with abundant basophilic mucinous secretion and associated with a fibromyxoid stroma. The tumor cells were diffusely positive for CK7 and SOX10 and variably positive for S100 and p63. Breakapart fluorescence in situ hybridization for SS18 confirmed rearrangement of this gene. Together, these findings support a primary cutaneous MSA, presumably arising from ceruminous glands of the ear canal. Based on current knowledge of its salivary gland counterpart, cutaneous MSA is expected to be locally invasive but unlikely to recur or metastasize on complete excision.
涎腺微分泌性腺癌（MSA）是最近被纳入《世界卫生组织头颈部肿瘤分类》的一种新实体肿瘤。这种肿瘤的特征是 MEF2C-SS18 易位的反复出现。我们报告了一例局限于耳道皮肤的结节状肿瘤，患者为 44 岁男性，其具有 MSA 的典型组织病理学特征和分子改变。具体而言，肿瘤由大量充满嗜碱性黏蛋白分泌物的小管和微囊组成，伴纤维黏液样基质。肿瘤细胞弥漫性表达 CK7 和 SOX10，部分表达 S100 和 p63。针对 SS18 的荧光原位杂交技术显示该基因发生了重排。综上所述，这些发现支持了原发性皮肤 MSA，可能来源于耳道的耵聍腺。根据对其涎腺对应物的现有认识，皮肤 MSA 预计具有局部侵袭性，但在完全切除后不太可能复发或转移。
