粘液表皮样癌是一种主要发生在唾液腺中的外分泌腺恶性肿瘤。它很少作为原发性皮肤癌遇到，在那些病人身上，它通常涉及外耳道。鉴于它们的稀有性,它们可以构成诊断挑战，并促使广泛的检查。在唾液腺中，粘液表皮样癌通常含有CRTC1/3::MAML2融合;然而，原发性皮肤肿瘤的遗传改变特征较少，与以前的研究报告CRTC1重排在没有MAML2畸变。在这里，我们报告了一例原发性外耳道皮肤粘液表皮样癌，CRTC1：：MAML2重排。我们还回顾了临床，形态学,和这种肿瘤的分子特征，并将它们与文献中报道的和组织病理学模拟物进行比较。
Mucoepidermoid carcinoma is a malignant neoplasm of exocrine glands that arises predominantly in salivary glands. It is seldom encountered as a primary cutaneous neoplasm, and in those patients, it often involves the external auditory canal. Given their rarity, they can pose a diagnostic challenge and prompt extensive workup. In salivary glands, mucoepidermoid carcinomas commonly harbor CRTC1/3::MAML2 fusions; however, genetic alterations of primary cutaneous neoplasms are less characterized, with previous studies reporting CRTC1 rearrangements in the absence of MAML2 aberrations. Herein, we report a case of a primary cutaneous mucoepidermoid carcinoma of the external auditory canal with a CRTC1::MAML2 rearrangement. We also review the clinical, morphologic, and molecular features of this neoplasm and compare them to those reported in the literature and to histopathologic mimics.
