Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.
Departments of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan.
Semin Diagn Pathol. 2024 Jul;41(4):197-206. doi: 10.1053/j.semdp.2024.04.002. Epub 2024 Apr 17.
High-grade carcinomas of the salivary glands are a group of several tumor entities with highly malignant histologic appearances, and have an aggressive biological behavior accompanied by poor a prognosis. In general, they require more intensive treatment than low- or intermediate-grade carcinomas. High-grade salivary carcinomas are rare and the microscopic features often overlap between different tumor types, making an appropriate diagnosis challenging in daily practice settings. However, with recent rapid advances in molecular pathology and molecular-targeted therapy in this field, there is a growing need to properly classify tumors, rather than just diagnosing the cases as "high-grade carcinomas". This leads to specific treatment strategies. In this article, we review representative high-grade salivary gland carcinomas, including salivary duct carcinoma and its histologic subtypes, high-grade mucoepidermoid carcinoma, solid-type adenoid cystic carcinoma, and high-grade transformation of low- or intermediate-grade carcinomas, and discuss their differential diagnoses and clinical implications. Other rare entities, such as neuroendocrine carcinoma, NUT carcinoma, and metastatic carcinoma, should also be considered before diagnosing high-grade carcinoma, NOS. Of these tumors, salivary duct carcinoma has received the most attention because of its strong association with androgen deprivation and anti-HER2 therapies. Other tumor-type-specific treatments include anti-TRK therapy for high-grade transformation of secretory carcinoma, but further therapeutic options are expected to be developed in the future. It should be emphasized that detailed histological evaluation with adequate sampling, in addition to the effective use of molecular ancillary tests, is of the utmost importance for a suitable diagnosis.
高等级唾液腺癌是一组具有高度恶性组织学表现的多种肿瘤实体，具有侵袭性的生物学行为，预后不良。一般来说，它们需要比低级别或中级别癌更强化的治疗。高等级唾液腺癌较为罕见，不同肿瘤类型之间的微观特征常常重叠，使得在日常实践环境中做出适当的诊断具有挑战性。然而，随着该领域分子病理学和分子靶向治疗的快速发展，越来越需要正确分类肿瘤，而不仅仅是将病例诊断为“高等级癌”。这导致了特定的治疗策略。在本文中，我们回顾了代表性的高等级唾液腺癌，包括唾液导管癌及其组织学亚型、高等级黏液表皮样癌、实性型腺样囊性癌和低级别或中级别癌的高等级转化，并讨论了它们的鉴别诊断和临床意义。在诊断高级别癌、NOS 之前，还应考虑其他罕见实体，如神经内分泌癌、NUT 癌和转移性癌。在这些肿瘤中，唾液导管癌因其与雄激素剥夺和抗 HER2 治疗的强烈关联而受到最多关注。其他肿瘤类型特异性治疗包括针对分泌癌高等级转化的抗 TRK 治疗，但预计未来会有更多的治疗选择。应强调的是，除了有效使用分子辅助测试外，详细的组织学评估和充分的样本采集对于合适的诊断至关重要。
