黑色素瘤的组织病理学诊断存在潜在的缺陷。在皮肤转移性黑色素瘤的情况下，要识别各种组织学模式，从常见到罕见，包括表皮型、毛囊型、痣状和类蓝痣样。此外，黑色素瘤以表型可塑性而著称。因此，存在许多不同的亚型和细胞形态变异，尤其是在复发或转移的情况下很难识别为黑色素瘤。本文将介绍选择的黑色素瘤变异体，包括原发性皮肤下层、透明细胞、浆细胞样、类信号环细胞、小细胞、粘液样、横纹样和分化不良型黑色素瘤，以及组合性黑色素细胞肿瘤。本文旨在提醒医师转移性疾病和选择罕见的黑色素瘤变异体的重要概念，同时提供准确诊断的实用指南。版权所有©2022年澳大利亚病理学皇家大学。由Elsevier B.V.出版。保留所有权利。

The histopathological diagnosis of melanoma is fraught with potential pitfalls. In the setting of cutaneous metastatic melanoma, it is important to recognise the various histological patterns that can be encountered from the more common to the rare, including epidermotropic, folliculotropic, naevoid, and blue naevus-like. In addition, melanoma is notorious for phenotypic plasticity. Thus, there are many different subtypes and cytomorphological variations that can be difficult to recognise as melanoma, particularly in the recurrent or metastatic setting. Select melanoma variants including primary dermal, clear cell, plasmacytoid, signet ring cell, small cell, myxoid, rhabdoid, and dedifferentiated melanoma will be discussed, in addition to composite melanocytic neoplasms. This review is intended to remind the practitioner of key concepts of metastatic disease and select rare melanoma variants, while providing practical guidelines for accurate diagnosis.Copyright © 2022 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.