Cohen Philip R., Zito Patrick M.
Touro University California College of Osteopathic Medicine
University of Miami; Miller School of Medicine
Melanoacanthoma is a rare, benign cutaneous neoplasm. The lesion is more common in older adults, with a median age of 65 and a male predominance. Cutaneous melanoacanthoma has an unclear etiology, though some argue the presentation is a heavily pigmented seborrheic keratosis variant. The initial presentation is typically a solitary, slow-growing black nodule on the head, neck, trunk, or extremities (see Cutaneous Melanoacanthoma on the Right Preauricular Cheek). Clinical examination, dermoscopy, and reflectance confocal microscopy of melanoacanthoma may be equivocal compared with malignant disease, so a biopsy with histopathologic evaluation is essential. Microscopic examination shows an epithelial lesion with hyperkeratosis, acanthosis, and papillomatosis. The epidermis has mixed melanocytes with large dendritic processes and keratinocytes. Further staining with Fontana-Masson, S100 protein, or Melan-A (ie, MART-1) may be required to pinpoint a diagnosis. Conservative excision of cutaneous melanoacanthoma is the treatment of choice since incomplete removal of the tumor can result in persistence and continued growth or recurrence of the lesion. Follow-up for patients with cutaneous melanoacanthoma should include evaluating any new or recurring lesions. Melanoacanthoma, called oral melanoacanthoma, may be present in the mouth (or other mucosal epithelium) and is thought to be reactive without tumor-like progression. See the StatPearls companion resource, "Oral Melanoacanthoma," for more information. In contrast, the neoplasm can also occur on non-mucosal sites as a benign neoplasm and is designated as a cutaneous melanoacanthoma. Considerable debate exists if pigmented seborrheic keratosis and cutaneous melanoacanthoma are 2 distinct entities, but they are considered separate, given their unique clinical features and management. Melanoacanthoma is associated with other syndromes. Metachronous oral melanoacanthomas were found in patients with Laugier-Hunziker syndrome, and melanoacanthoma on the lower lip has been associated with plasma cell cheilitis and Langerhans cell hyperplasia of the lower lip.
黑素棘皮瘤是一种罕见的良性皮肤肿瘤。该病变在老年人中更为常见，中位年龄为65岁，男性居多。皮肤黑素棘皮瘤的病因尚不清楚，不过有人认为其表现是一种色素沉着严重的脂溢性角化病变体。最初的表现通常是头部、颈部、躯干或四肢出现单个、生长缓慢的黑色结节（见右耳前脸颊处的皮肤黑素棘皮瘤）。与恶性疾病相比，黑素棘皮瘤的临床检查、皮肤镜检查和反射式共聚焦显微镜检查可能难以明确诊断，因此进行组织病理学评估的活检至关重要。显微镜检查显示为具有角化过度、棘层肥厚和乳头瘤病的上皮病变。表皮有混合的黑素细胞，其具有大的树枝状突起和角质形成细胞。可能需要进一步用Fontana-Masson染色、S100蛋白或Melan-A（即MART-1）染色来明确诊断。皮肤黑素棘皮瘤的治疗选择是保守切除，因为肿瘤切除不完全可导致病变持续存在、继续生长或复发。皮肤黑素棘皮瘤患者的随访应包括评估任何新出现或复发的病变。黑素棘皮瘤，称为口腔黑素棘皮瘤，可能出现在口腔（或其他黏膜上皮），被认为是反应性的，无肿瘤样进展。更多信息见StatPearls配套资源“口腔黑素棘皮瘤”。相比之下，该肿瘤也可作为良性肿瘤发生在非黏膜部位，被称为皮肤黑素棘皮瘤。色素沉着性脂溢性角化病和皮肤黑素棘皮瘤是否为两个不同的实体存在相当大的争议，但鉴于它们独特的临床特征和治疗方法，它们被视为不同的疾病。黑素棘皮瘤与其他综合征有关。在劳吉尔 - 洪齐克尔综合征患者中发现了异时性口腔黑素棘皮瘤，下唇的黑素棘皮瘤与浆细胞性唇炎和下唇朗格汉斯细胞增生有关。
