Department of Pathology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Department of Pathology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Int J Surg Pathol. 2024 Jun;32(4):679-683. doi: 10.1177/10668969231188892. Epub 2023 Jul 31.
The difficulty in diagnosis of severe melanocytic lesions is a problem to be overcome in pathological practice. Melanin bleaching is an effective approach to ameliorate melanin disturbances in severely pigmented lesions. Although various methods for improving melanin pigmentation in immunohistochemical staining have been reported, these depigmentation methods still need to be optimized and standardized. In this study, the coloring efficiency of 3,3'-diaminobenzidine (DAB) and alkaline phosphatase (AP) after melanin depigmentation was compared under the automatic immunohistochemical staining platform. The applicability of the optimized depigmentation method was validated in 10 formalin-fixed paraffin-embedded (FFPE) blocks of ocular melanoma tissues. Specimens were demelaninized with 10% hydrogen peroxide at 60°C for immunohistochemical staining (Melan-A and SOX10), and tissue chromogenic staining was performed with DAB and AP detection systems, respectively. The optimized depigmentation method including immunohistochemistry (IHC) could be completed in 3 h, effectively preserving cell morphology and immunoreactivity. Among these, the color-rendering effect and contrast of AP are better than DAB. This optimized method can effectively remove melanin and improve the accuracy of IHC staining interpretation. AP staining has better visibility and readability without the interference of residual melanin. The comparison results showed that after melanin depigmentation, the immunohistochemical staining agent was replaced with red AP, which avoided the misjudgment caused by brown DAB when melanin depigmentation was incomplete. This improved method can be applied to future histopathological and immunohistochemical staining of melanin-deposited tissues.
诊断严重黑素细胞病变的困难是病理实践中需要克服的问题。黑色素漂白是改善严重色素沉着病变中黑色素紊乱的有效方法。尽管已经报道了各种改善免疫组织化学染色中黑色素染色的方法，但这些脱色方法仍需要优化和标准化。在这项研究中，在自动免疫组织化学染色平台下比较了 3,3'-二氨基联苯胺（DAB）和碱性磷酸酶（AP）在黑色素脱色后的显色效率。在 10 例眼黑色素瘤组织的福尔马林固定石蜡包埋（FFPE）块中验证了优化脱色方法的适用性。用 10%过氧化氢在 60°C 下对标本进行脱黑色素处理，用于免疫组织化学染色（Melan-A 和 SOX10），并分别使用 DAB 和 AP 检测系统进行组织显色染色。包括免疫组织化学（IHC）在内的优化脱色方法可以在 3 小时内完成，有效地保持细胞形态和免疫反应性。其中，AP 的显色效果和对比度优于 DAB。该优化方法可以有效地去除黑色素，提高免疫组织化学染色解释的准确性。AP 染色具有更好的可视性和可读性，没有残留黑色素的干扰。比较结果表明，黑色素脱色后，用红色的 AP 替代免疫组织化学染色剂，避免了黑色素脱色不完全时棕色 DAB 造成的误判。这种改进的方法可以应用于未来黑色素沉积组织的组织病理学和免疫组织化学染色。
