BRCA1 相关蛋白 1 (BAP1) 失活肿瘤 (BIMT) 是罕见的黑素细胞肿瘤，可能会被误认为 Spitz 肿瘤或黑色素瘤。它们偶尔发生或与 BAP1 肿瘤易感综合征 (BAP1-TPDS) 相关，该综合征可能并发葡萄膜或皮肤黑色素瘤、间皮瘤、基底细胞癌和肾细胞癌。本研究的目的是表征大型患者队列中 BIMT 黑色素瘤优先表达抗原 (PRAME) 的临床病理学特征和免疫组织化学表达模式。获得了伦理批准，审查了苏木精和伊红染色的载玻片，PRAME 免疫组织化学进行并从患者记录中获得临床随访。确定了来自 38 名患者的 65 个 BIMT (F:M = 4.4:1)。 BIMT 通常位于躯干、头部和颈部（中位尺寸 = 0.5 cm）。 7 名 BAP1-TPDS 患者（范围 = 16-66 岁，中位 = 25）有多个 BIMT（中位 = 5），而散发性 BIMT 为孤立性（中位患者年龄 = 39 岁）。七名 BAP1-TPDS 患者中的一名出现其他恶性肿瘤（间皮瘤和皮肤梭形细胞黑色素瘤），并死于间皮瘤并发症。所有其他患者均存活且未出现 BIMT 复发（中位随访时间 = 42 个月）。 63% 的病例中 BIMT 表现为皮内结节状上皮样黑素细胞聚集体，有丝分裂活性低，细胞学异型性中度至重度。 64% 的人存在背景常规痣。 PRAME 免疫组织化学在所有 BIMT 中均显示阴性或弱斑片状阳性染色。尽管令人担忧的细胞学异型性，BIMT 在散发环境中更常见，并且表现惰性。 PRAME 免疫组织化学是区分 BIMT 和黑色素瘤的可靠工具。© 2024 作者。组织病理学由约翰·威利出版

BRCA1-associaed protein-1 (BAP1) inactivated tumours (BIMT) are rare melanocytic tumours that may be mistaken for Spitz tumours or melanoma. They occur sporadically or in association with the BAP1 tumour predisposition syndrome (BAP1-TPDS), which may be complicated by uveal or cutaneous melanoma, mesothelioma, basal cell carcinoma and renal cell carcinoma. The aim of this study was to characterise the clinicopathological features and the immunohistochemical expression pattern of preferentially expressed antigen in melanoma (PRAME) of BIMT in a large patient cohort.Ethical approval was obtained, haematoxylin and eosin-stained slides were reviewed, PRAME immunohistochemistry was performed and clinical follow-up was obtained from patient records. Sixty-five BIMT from 38 patients (F:M = 4.4:1) were identified. BIMT were typically located on the trunk and head and neck (median size = 0.5 cm). Seven patients with BAP1-TPDS (range = 16-66 years, median = 25) had multiple BIMT (median = 5), while sporadic BIMT were solitary (median patient age = 39 years). One of seven patients with BAP1-TPDS developed additional malignancies (mesothelioma and cutaneous spindle cell melanoma) and died of complications of mesothelioma. All other patients are alive without recurrence of BIMT (median follow-up = 42 months). BIMT presented as intradermal, nodular aggregates of epithelioid melanocytes with low mitotic activity and moderate to severe cytological atypia in 63% of cases. A background conventional naevus was present in 64%. PRAME immunohistochemistry showed negative or weakly patchy positive staining in all BIMT.BIMT are more common in a sporadic setting and behave indolently, despite worrying cytological atypia. PRAME immunohistochemistry is a reassuring tool in distinguishing BIMT from melanoma.© 2024 The Author(s). Histopathology published by John Wiley & Sons Ltd.