A 9-y-5-mo-old, spayed female, mixed-breed dog with buphthalmia and elevated intraocular pressure in the left eye, consistent with glaucoma, was evaluated. Black-pigmented, slightly elevated tissue with irregular margins was noted on the dorsolateral aspect of the left globe. Ultrasonography detected a mass, later identified as lacrimal gland, adjacent to the globe and the thickened uvea. The surgically removed lacrimal gland was effaced by dense sheets of melanin-laden cells. Within the enucleated globe, numerous melanin-laden cells infiltrated and expanded the rostral two-thirds thickness of the cornea, the entire anterior uvea (iris and ciliary body), and a rostral portion of the choroid. Melanin-laden cells in the left lacrimal gland and globe showed no nuclear atypia or mitotic figures, and reacted to anti-S100 and anti–melan A antibodies by immunohistochemistry. Our final diagnosis was concurrent lacrimal gland melanocytoma and ocular melanocytosis. The trabecular meshwork of the eye was obliterated by melanin-laden cells, which was the likely cause of glaucoma in this patient. To our knowledge, melanocytoma affecting the lacrimal gland has not been reported previously in a non-human mammalian species. Veterinary clinicians are encouraged to include melanocytoma in the differential list when examining an enlarged lacrimal gland.

评估了一只 9 岁、5 个月大、已绝育的雌性混种狗，患有白眼病和左眼眼压升高，与青光眼一致。在左眼球的背外侧观察到黑色的、轻微隆起的组织，边缘不规则。超声检查发现一个肿块，后来被确定为泪腺，靠近眼球和增厚的葡萄膜。手术切除的泪腺被致密的富含黑色素的细胞层抹去。在去核球内，大量黑色素细胞浸润并扩大了角膜喙侧三分之二的厚度、整个前葡萄膜（虹膜和睫状体）和脉络膜的喙侧部分。左侧泪腺和眼球中的黑色素细胞没有显示核异型性或有丝分裂图，并通过免疫组织化学与抗 S100 和抗黑色素 A 抗体发生反应。我们的最终诊断是并发泪腺黑色素细胞瘤和眼部黑色素细胞增多症。眼睛的小梁网被充满黑色素的细胞所破坏，这可能是该患者青光眼的原因。据我们所知，影响泪腺的黑素细胞瘤以前没有在非人类哺乳动物物种中报道过。鼓励兽医临床医生在检查扩大的泪腺时将黑色素细胞瘤包括在鉴别列表中。以前在非人类哺乳动物物种中没有报道影响泪腺的黑素细胞瘤。鼓励兽医临床医生在检查扩大的泪腺时将黑色素细胞瘤包括在鉴别列表中。以前在非人类哺乳动物物种中没有报道影响泪腺的黑素细胞瘤。鼓励兽医临床医生在检查扩大的泪腺时将黑色素细胞瘤包括在鉴别列表中。