Mori Hidetsugu, Takahashi Kanji
Department of Ophthalmology, Kansai Medical University, Osaka, Japan.
Ocul Oncol Pathol. 2017 Dec;4(1):38-43. doi: 10.1159/000477735. Epub 2017 Jul 19.
Retinal pigment epithelium (RPE) adenocarcinoma is a very rare malignant intraocular tumor. Herein we describe the histopathological features of RPE adenocarcinoma.
A 36-year-old male was referred to our clinic because of floaters in his left eye. The initial diagnosis was malignant melanoma of the choroid. We resected the tumor and studied it histopathologically. The tumor tissue was investigated by light microscopy including immunohistochemistry using antibodies against S-100, HMB-45, EMA, and AE-1. Electron microscopic examination was also performed.
The tumor arose from the RPE and contained intracytoplasmic vacuoles and abundant melanin pigment. There were no nevoid cells in the choroid. A small part of the tumor cells showed tubular or lobular proliferation and choroidal invasion. Immunohistochemistry revealed positive staining in tumor cells with 4 antibodies. Tight cellular junctions specific to the RPE were confirmed by electron microscopy. The final diagnosis was RPE adenocarcinoma.
Most pigmented intraocular tumors are nevus and malignant melanomas of the choroid. It is easy to misdiagnose a RPE adenocarcinoma as a malignant melanoma of the choroid. An exact differential diagnosis should be determined by immunohistopathological and electron microscopic examination.
视网膜色素上皮（RPE）腺癌是一种非常罕见的眼内恶性肿瘤。在此我们描述RPE腺癌的组织病理学特征。
一名36岁男性因左眼出现飞蚊症转诊至我院。初步诊断为脉络膜恶性黑色素瘤。我们切除了肿瘤并进行了组织病理学研究。使用抗S-100、HMB-45、EMA和AE-1抗体通过包括免疫组织化学在内的光学显微镜对肿瘤组织进行了研究。还进行了电子显微镜检查。
肿瘤起源于RPE，含有胞浆内空泡和丰富的黑色素。脉络膜中没有痣样细胞。肿瘤细胞的一小部分显示出管状或小叶状增生以及脉络膜浸润。免疫组织化学显示肿瘤细胞对4种抗体呈阳性染色。通过电子显微镜证实了RPE特有的紧密细胞连接。最终诊断为RPE腺癌。
大多数色素性眼内肿瘤是脉络膜痣和恶性黑色素瘤。RPE腺癌很容易被误诊为脉络膜恶性黑色素瘤。应通过免疫组织病理学和电子显微镜检查来确定准确的鉴别诊断。
