Ball R A, Genest D, Sander M, Schmidt B, Barnhill R L
Division of Dermatopathology, Harvard Medical School, Brigham and Women's Hospital, Boston, Mass, USA.
Arch Dermatol. 1998 Jun;134(6):711-4. doi: 10.1001/archderm.134.6.711.
Placental metastases from cutaneous malignant melanoma from both the mother and the fetus have been reported. The finding of benign-appearing melanocytes in the placenta in association with congenital melanocytic nevi (CMN) is more exceptional, with only 6 reports in the literature. Clinically, the finding of melanocytes in the placenta in this setting can be alarming and might erroneously lead to the diagnosis of metastatic melanoma.
Herein, we describe 3 additional patients with CMN with placental infiltration by melanocytes with a benign phenotype. In the results of immunoperoxidase stains, the melanocytic cells were positive for S-100 protein and HMB-45 in the 2 lesions available for study. Staining of placental vessels with Ulex europaeus agglutinin I (Vector Laboratories, Burlingame, Calif) failed to show intravascular melanocytes in the 1 lesion available for study. We report for the first time DNA diploidy in 2 lesions available for study, which were analyzed by DNA image cytometry. We describe the first patient with a relatively small, nongiant CMN.
We support the notion of the aberrant migration of melanocytes from the neural crest during fetal development as the most likely explanation of this phenomenon and note the similarity to the association of CMN and leptomeningeal melanocytosis. However, the precise histogenesis of this process remains uncertain. Most importantly, our data provide further evidence for the benign nature of this condition. Awareness of this entity is of vital importance in avoiding overdiagnosis of melanoma in this clinical setting.
已有报道称母体和胎儿的皮肤恶性黑色素瘤可发生胎盘转移。在胎盘中发现外观良性的黑素细胞并伴有先天性黑素细胞痣（CMN）的情况更为罕见，文献中仅有6例报道。临床上，在此种情况下在胎盘中发现黑素细胞可能令人担忧，并可能错误地导致转移性黑色素瘤的诊断。
在此，我们描述了另外3例CMN患者，其胎盘有良性表型的黑素细胞浸润。在免疫过氧化物酶染色结果中，可用于研究的2个病变中的黑素细胞S-100蛋白和HMB-45呈阳性。用荆豆凝集素I（Vector Laboratories，加利福尼亚州伯林盖姆）对胎盘血管进行染色，在可用于研究的1个病变中未显示血管内黑素细胞。我们首次报告了可用于研究的2个病变中的DNA二倍体情况，这些病变通过DNA图像细胞术进行了分析。我们描述了首例患有相对较小的非巨大型CMN的患者。
我们支持胎儿发育过程中黑素细胞从神经嵴异常迁移这一观点，认为这是对此现象最可能的解释，并指出其与CMN和软脑膜黑素细胞增多症关联的相似性。然而，这一过程的确切组织发生学仍不确定。最重要的是，我们的数据为这种情况的良性本质提供了进一步证据。认识到这一实体对于避免在此临床环境中对黑色素瘤的过度诊断至关重要。
