Northcutt A D
Central Texas Pathology Laboratory, P.A. Waco, Texas 76708, USA.
Am J Dermatopathol. 2000 Apr;22(2):176-8. doi: 10.1097/00000372-200004000-00016.
Xanthomas of the skin may mimic balloon cell melanoma because 1) both lesions may exhibit a diffuse dermal proliferation of cytologically similar large vacuolated or clear cells with distinct cytoplasmic membranes, 2) dermal maturation (smaller deep dermal nuclei) is absent in both lesions, 3) melanin pigment is usually absent in balloon cell melanoma, 4) cellular atypia may be minimal in balloon cell melanoma, and 5) mitoses may be absent or rare in balloon cell melanoma. We report a unique xanthoma, which further simulated melanoma by exhibiting epidermotropism and a pseudonesting pattern at the dermal-epidermal junction. The correct diagnosis was made with an immunohistochemical panel revealing tumor cell positivity for CD68 and negativity for S-100 protein and MART-1. Immunohistochemical studies may be required in the critical differential diagnosis of epidermotropic xanthoma and amelanotic balloon cell melanoma.
皮肤黄色瘤可能会模仿气球状细胞黑色素瘤，原因如下：1）两种病变均可表现为细胞学上相似的大空泡状或透明细胞在真皮内弥漫性增殖，且具有明显的细胞质膜；2）两种病变均无真皮成熟现象（真皮深层细胞核较小）；3）气球状细胞黑色素瘤通常无黑色素沉着；4）气球状细胞黑色素瘤的细胞异型性可能最小；5）气球状细胞黑色素瘤可能无或罕见有丝分裂象。我们报告了一例独特的黄色瘤，其通过在真皮-表皮交界处表现出亲表皮性和假巢状模式，进一步模拟了黑色素瘤。通过免疫组织化学检测发现肿瘤细胞CD68呈阳性，S-100蛋白和MART-1呈阴性，从而做出了正确诊断。在亲表皮性黄色瘤和无黑色素气球状细胞黑色素瘤的关键鉴别诊断中，可能需要进行免疫组织化学研究。
