Kurotaki T, Tomonari Y, Kanno T, Wako Y, Tsuchitani M
Pathology Division, Kashima Laboratory, Mitsubishi Chemical Safety Institute Ltd., 14 Sunayama, Kamisu-shi, Ibaraki-ken, Japan.
Vet Pathol. 2008 May;45(3):383-7. doi: 10.1354/vp.45-3-383.
In albino rats, spontaneous occurrence of melanocytic tumors is rare, with diagnosis difficult. This study evaluated immunoreactivity for PNL2 in normal and neoplastic melanocytes in formalin-fixed and paraffin-embedded tissues of albino rats. The samples consisted of 11 (1.57%) amelanotic melanomas in 700 rats (2 studies), 23 non-melanocytic tumors, and a wide variety of normal tissues. In normal albino rats, PNL2 stained the melanocytes in the iris and choroid of the eyeball and the hair bulb and basal cell layers of the epidermis of the whole body. In amelanotic melanoma, the tumor cells consisted of spindle cells with eosinophilic cytoplasm without melanin granules. PNL2 consistently stained cytoplasm in all amelanotic melanoma cells. In contrast, the nonmelanocytic tumor cells were not labeled. Electron microscopically, neoplastic, and normal melanocytes showed numerous cytoplasmic premelanosomes (stage II melanosome). In conclusion, PNL2 is direct against a fixative- and decalcific-resistant melanocyte-associated antigen, and has high specificity against normal and neoplastic melanocytes of albino rats.
在白化大鼠中，黑素细胞肿瘤的自发发生率很低，诊断困难。本研究评估了PNL2在白化大鼠福尔马林固定石蜡包埋组织中正常和肿瘤性黑素细胞中的免疫反应性。样本包括700只大鼠（2项研究）中的11例（1.57%）无色素性黑素瘤、23例非黑素细胞肿瘤以及多种正常组织。在正常白化大鼠中，PNL2可使眼球虹膜和脉络膜中的黑素细胞以及全身表皮的毛球和基细胞层染色。在无色素性黑素瘤中，肿瘤细胞由具有嗜酸性细胞质且无黑色素颗粒的梭形细胞组成。PNL2始终使所有无色素性黑素瘤细胞的细胞质染色。相比之下，非黑素细胞肿瘤细胞未被标记。电子显微镜下，肿瘤性和正常黑素细胞均显示出大量细胞质前黑素小体（II期黑素小体）。总之，PNL2针对一种抗固定剂和抗脱钙的黑素细胞相关抗原，对白化大鼠的正常和肿瘤性黑素细胞具有高度特异性。
