Fukui Daisuke, Bando Gen, Kosuge Masao, Yamaguchi Masanori, Shibahara Tomoyuki, Kadota Koichi
Asahikawa Zoological Park and Wildlife Conservation Center, Higashi-Asahikawa, Japan.
J Vet Med Sci. 2002 Mar;64(3):261-4. doi: 10.1292/jvms.64.261.
A 6-year-old male red squirrel (Sciurus vulgaris orientis) developed bilateral tumors of upper and lower eyelids. The tumors in the left lid recurred despite surgical removal. Necropsy revealed metastasis to the lung. The neoplastic cells were epithelioid and highly pleomorphic, and only a few cells contained melanin granules. Occasionally melanoma cells were immunoreactive for S100, neuron-specific enolase and vimentin, and a small number of cells for cytokeratin. Ultrastructurally, the presence of premelanosomes was confirmed in the cytoplasm. Possible presence of cytokeratin-positive neoplastic melanocytes should be taken into account when differentiating a nonpigmented epithelioid melanoma from other tumors such as anaplastic carcinomas.
一只6岁雄性东方红松鼠（Sciurus vulgaris orientis）双侧上下眼睑出现肿瘤。尽管手术切除，但左眼睑肿瘤仍复发。尸检显示肿瘤已转移至肺部。肿瘤细胞呈上皮样，高度多形性，仅有少数细胞含有黑色素颗粒。偶尔，黑色素瘤细胞对S100、神经元特异性烯醇化酶和波形蛋白呈免疫反应，少数细胞对细胞角蛋白呈免疫反应。超微结构显示细胞质中存在前黑素小体。在将无色素上皮样黑色素瘤与其他肿瘤（如间变性癌）区分开来时，应考虑可能存在细胞角蛋白阳性的肿瘤性黑素细胞。
