Zoroquiain Pablo, Ganimi Maria Sb, Alghamdi Sarah, Burnier Julia V, Aldrees Sultan S, Burnier Miguel N
Department of Pathology, Henry C Witelson Ocular Pathology Laboratory, McGill University, 1001 Boul Decarie, Montreal H4A 3J1, Canada; Department of Pathology, School of Medicine, Pontificia Universidad Catolica de Chile, Marcoleta 377, Santiago 8330024, Chile.
Faculdade de Ciências Médicas e da Saúde de Juiz de Fora, Suprema, Alameda Salvaterra, 200 - Salvaterra, Juiz de Fora - MG 36033-003, Brazil.
Ecancermedicalscience. 2016 Feb 12;10:620. doi: 10.3332/ecancer.2016.620. eCollection 2016.
Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis.
结膜黑色素瘤是一种罕见的眼部恶性肿瘤。由于普通病理学家对眼部活检的接触较少且鉴别诊断范围广泛，其诊断对他们来说是一项挑战。此外，结膜样本通常较小，并且由于处理过程，其伪像出现频率较高。在此，我们报告首例伪装成结膜黑素细胞肿瘤的外伤性虹膜脱出病例。一名83岁的亚洲男性患者出现一个结膜色素沉着结节，周围有一片弥漫性色素沉着区域。组织病理学显示，结节内有一个边界清晰的病变，由梭形黑素细胞和厚壁血管组成。在高倍镜下，血管壁增厚，胶原纤维呈洋葱皮样排列。组织学表现与脱出的虹膜组织一致。对扁平色素沉着病变进行的地图活检显示，黑素细胞增殖，树突状突起局限于固有层，无任何上皮受累，符合眼部黑素细胞增多症。结膜黑素细胞病变的诊断具有挑战性，鉴别诊断中应始终考虑非肿瘤性疾病。病理学家应将临床病理结果相互关联，并熟悉正常组织学，以做出正确诊断。
