Assistant Professor, Department of Cutaneous Oncology and Pathology, Moffitt Cancer Center, Tampa, FL.
Resident, Department of Pathology, Oregon Health and Science University, Portland, OR.
Am J Dermatopathol. 2020 May;42(5):313-321. doi: 10.1097/DAD.0000000000001551.
The family of blue nevi includes the common blue nevus (BN), cellular blue nevus (CBN), and atypical BN, while melanomas with BN-like morphology can either arise in association with a blue nevus (MABN) or in the de novo setting mimicking cellular blue nevus (MMCBN). Recent molecular and immunohistochemical studies have demonstrated loss of BAP-1 in MABN/MMCBN but not in BN/CBN, suggesting that loss of BAP-1 correlates with a malignant phenotype in these lesions. In this study, we applied anti-BAP-1 antibodies to a series of CBN/BN (n = 11) and MABN/MMCBN (n = 4). Nuclear BAP-1 expression was detected in the majority of CBN/BN (n = 10/11) but was lost in 1 case. Most cases of MABN/MMCBN showed loss of nuclear BAP-1 expression (n = 3/4), with one case of MMCBN showing preserved BAP-1 expression. Demonstration of BAP-1 loss in a single case of CBN and preservation of BAP-1 expression in 1 case of MMCBN may indicate that detection of alterations in BAP-1 protein expression by immunohistochemistry may not be a completely reliable biomarker for the distinction of BN/CBN from MABN/MMCBN. Further investigation of the significance of BAP-1 loss/preservation in BN-like tumors is warranted.
蓝色痣家族包括常见的蓝色痣 (BN)、细胞性蓝色痣 (CBN) 和不典型 BN，而具有 BN 样形态的黑色素瘤可以与蓝色痣相关（MABN）或在模拟细胞性蓝色痣（MMCBN）的新发病理中出现。最近的分子和免疫组织化学研究表明，MABN/MMCBN 中存在 BAP-1 的缺失，但 BN/CBN 中不存在，这表明 BAP-1 的缺失与这些病变中的恶性表型相关。在这项研究中，我们应用抗 BAP-1 抗体对一系列 CBN/BN（n = 11）和 MABN/MMCBN（n = 4）进行了检测。大多数 CBN/BN（n = 10/11）中检测到核 BAP-1 表达，但有 1 例丢失。大多数 MABN/MMCBN 病例显示核 BAP-1 表达缺失（n = 3/4），1 例 MMCBN 病例显示 BAP-1 表达保留。CBN 中单个病例中 BAP-1 的缺失和 MMCBN 中 1 例中 BAP-1 表达的保留表明，通过免疫组织化学检测 BAP-1 蛋白表达的改变可能不是区分 BN/CBN 和 MABN/MMCBN 的完全可靠的生物标志物。进一步研究 BAP-1 缺失/保留在 BN 样肿瘤中的意义是必要的。
