Gerami Pedram, Pouryazdanparast Pedram, Vemula Swapna, Bastian Boris C
From the Departments of *Dermatology and †Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL; and ‡Departments of Dermatology and Pathology, and UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA.
Am J Dermatopathol. 2010 May;32(3):301-305. doi: 10.1097/DAD.0b013e3181b96db7.
Nevus of Ota is a variant of congenital nevus, which is morphologically paucicellular and resembles a common blue nevus. Although nevus of Ota is a risk factor for uveal melanoma in white people, the development of cutaneous melanoma within nevus of Ota is a very rare occurrence with only a few reported cases. We present a case of a long-standing nevus of Ota, with radiologic imaging demonstrating a large retro-orbital mass and a biopsy showing melanoma. The histopathology of the eye exenteration specimen illustrated various stages of melanocytic progression including areas resembling a nevus of Ota, blue nevus, cellular blue nevus, and melanoma. There was heterogeneity in the overtly malignant sections with some areas displaying expansile nodules of blander appearing spindled cells, whereas other areas were composed of epithelioid cells with higher mitotic counts and zones of necrosis. The extensive lesion also infiltrated the soft tissue and bone. We performed gene mutation analysis for GNAQ, BRAF, NRAS, and KIT and fluorescence in situ hybridization (FISH) targeting commonly altered chromosomal loci in melanoma and comparative genomic hybridization (CGH). Copy number changes typical of melanoma were identified by both FISH and CGH in the morphologically malignant areas illustrating the relationship of tumor progression and the progressive acquisition of genetic aberrations.
太田痣是先天性痣的一种变体，其形态学上细胞稀少，类似于普通蓝痣。虽然太田痣在白人中是葡萄膜黑色素瘤的一个危险因素，但太田痣内发生皮肤黑色素瘤是非常罕见的情况，仅有少数病例报道。我们报告一例长期存在的太田痣病例，放射影像学显示眶后有一个大肿块，活检显示为黑色素瘤。眼球摘除标本的组织病理学显示了黑素细胞进展的各个阶段，包括类似太田痣、蓝痣、细胞蓝痣和黑色素瘤的区域。明显恶性的切片存在异质性，一些区域显示出由较温和的梭形细胞组成的膨胀性结节，而其他区域则由有较高有丝分裂计数和坏死区域的上皮样细胞组成。广泛的病变还浸润了软组织和骨骼。我们对GNAQ、BRAF、NRAS和KIT进行了基因突变分析，并对黑色素瘤中常见的染色体位点改变进行了荧光原位杂交（FISH）和比较基因组杂交（CGH）。在形态学上恶性的区域，通过FISH和CGH均鉴定出典型的黑色素瘤拷贝数变化，说明了肿瘤进展与遗传畸变的逐步获得之间的关系。
