据说原发性皮肤黏液汗腺癌可以通过神经内分泌分化进行预后分层，然而，这种断言是基于历史数据和过时的染色技术。我们的目的是评估黏液性和非黏液性附属肿瘤中表达新型、更敏感的神经内分泌标记物胰岛素瘤相关蛋白1 (INSM1) 的百分比，并通过这种表型对患者的临床病理特征进行评估。在12例可获得的附属/皮肤腺癌中，9例是黏液性的，其中3例是INSM1阴性，其中2例有淋巴结转移。在3例非黏液性病例中，所有病例均为INSM1阴性，其中1例有淋巴结转移，2例有淋巴管侵犯。相比之下，在6例黏液性INSM1阳性病例中，没有病例有淋巴管侵犯或转移，然而，在随访期间有3名患者死亡，其中2名患有乳腺或膀胱上皮癌。第四位患者发生了乳腺癌。INSM1阳性的肿瘤来自颊部（3例）、头皮（2例）和下巴（1例），它们的雌激素受体和孕激素受体呈阳性。未发现有INSM1标记的分泌性腺瘤或汗腺囊瘤、基底细胞或皮脂腺癌的病例。虽然大多数原发性皮肤黏液癌是神经内分泌型，但我们的研究证实了偶发的非神经内分泌型黏液癌的存在。我们验证了这类肿瘤与非神经内分泌型的附属腺癌具有中级别行为的关联，包括淋巴结转移，但不包括死亡。相反，表达神经内分泌的原发性皮肤黏液癌可能代表原发于皮肤的分化良好的神经内分泌肿瘤，具有低级别行为，但存在其他侵袭性皮肤外肿瘤的遗传易感风险。建议对皮肤附属癌进行常规检查，使用INSM1标记，并对具有阳性染色的患者进行长期随访和癌症筛查。

Primary cutaneous mucinous sweat gland carcinoma is said to be prognostically stratifiable by neuroendocrine differentiation, however, this assertion is based on historical data and older staining techniques. We aimed to evaluate the percentage of mucinous and nonmucinous adnexal tumors expressing the newer, more sensitive neuroendocrine marker insulinoma-associated protein 1 (INSM1), and to assess clinicopathologic features in patients cohorted by this phenotype. Of 12 available adnexal/cutaneous adenocarcinomas, 9 were mucinous, 3/9 of which were INSM1-negative, and 2/3 with nodal metastases. Of 3 nonmucinous cases, all were INSM1-negative, 1/3 with nodal metastasis, and 2/3 with lymphovascular invasion. In contrast, of 6 mucinous INSM1-positive cases, no cases had LVI or metastasis, however, 3 patients died during follow-up, 2 from breast or urothelial cancer. A fourth patient developed breast carcinoma. INSM1-positive tumors, from cheek (3), scalp (2), and chin (1) were estrogen receptor and progesterone receptor positive. No cases of apocrine adenoma or hidrocystoma, basal cell, or sebaceous carcinoma labeled with INSM1. While most primary cutaneous mucinous carcinomas are of the neuroendocrine type, our study confirms the presence of occasional non-neuroendocrine mucinous carcinomas. We validate the association of such tumors and nonmucinous non-neuroendocrine adnexal carcinoma with intermediate-grade behavior, including lymph node metastases, but not death. Conversely, neuroendocrine expressing primary cutaneous mucinous carcinoma may represent the well-differentiated neuroendocrine neoplasm/neuroendocrine tumor primary to skin, with low-grade behavior, but attendant risk of germline susceptibility to other aggressive extracutaneous tumors. Routine assessment of cutaneous adnexal carcinoma with INSM1 and longer term follow-up and cancer screening of patients with positive staining is recommended.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.