Harvard Combined Dermatology Residency Training Program, Boston, Massachusetts, USA.
Harvard Medical School, Boston, Massachusetts, USA.
Pediatr Dermatol. 2024 Sep-Oct;41(5):822-824. doi: 10.1111/pde.15705. Epub 2024 Jul 30.
Cutaneous BAP1-inactivated melanocytomas (BIM) are melanocytic proliferations defined histopathologically by an epithelioid, predominantly dermal melanocytic proliferation with loss of BAP1, and have been largely characterized in adult patients but less well-described in pediatric cohorts. BIM share overlapping histological features with those seen in Spitz nevi; however, unlike Spitz nevi, the majority of BIM carry both BAP1 and BRAF mutations. This study investigated the potential overlap of BIMs with pediatric Spitz nevi by performing immunohistochemical staining of BAP1 and BRAF on pediatric melanocytic tumors with banal Spitz and dermal features. None of the stained tumors in our study exhibited the concurrent BAP1 loss and BRAF positivity that are characteristic of adult BIM, suggesting that this is a low-frequency mutation among banal tumors in the pediatric population.
皮肤 BAP1 失活的黑色素细胞瘤（BIM）是一种组织病理学定义的黑色素细胞增生，表现为上皮样、主要位于真皮的黑色素细胞增生，伴有 BAP1 缺失，主要在成年患者中得到广泛描述，但在儿科患者中描述较少。BIM 与 Spitz 痣具有重叠的组织学特征；然而，与 Spitz 痣不同的是，大多数 BIM 同时携带 BAP1 和 BRAF 突变。本研究通过对具有普通 Spitz 和真皮特征的儿童黑色素瘤进行 BAP1 和 BRAF 的免疫组织化学染色，研究了 BIM 与儿童 Spitz 痣之间的潜在重叠。我们研究中的染色肿瘤均未表现出同时存在的 BAP1 缺失和 BRAF 阳性，这是成人 BIM 的特征，表明这是儿科普通肿瘤中低频突变。
