Kerlin R L, Roesler A R, Jakowski A B, Boucher G G, Krull D L, Appel W H
Drug Safety Evaluation Department, Pfizer Central Research, Groton, Connecticut 06340, USA.
Toxicol Pathol. 1998 Sep-Oct;26(5):691-4. doi: 10.1177/019262339802600515.
A large neoplasm that replaced 1 testis of a Long Evans Rat was noted at the final necropsy of a dietary 2-yr study. By light microscopy, the morphological features were consistent with a poorly differentiated seminoma. Ultrastructurally, the cells were polygonal, had a round nucleus, had straight cellular boundaries, and bore no resemblance to Sertoli cells. Although there was little evidence of spermatocytic differentiation, the presence of proacrosomal granules and vesicles, prominent Golgi apparatus, tight intercellular junctions, and a few centriolar pairs without axoneme development, in conjunction with the absence of lipid droplets or abundant smooth endoplasmic reticulum, supported the diagnosis of seminoma rather than Leydig cell tumor. The cells were S-100- and vimentin-positive, although cytokeratin- and alpha-fetoprotein-negative. Seminomas are extremely rare neoplasms in rats; this is the first report in this strain and the first extensive analysis of a rat seminoma without spermatocytic differentiation.
在一项为期两年的饮食研究的最终尸检中，发现一只长 Evans 大鼠的一侧睾丸被一个大肿瘤取代。通过光学显微镜检查，形态学特征与低分化精原细胞瘤一致。超微结构上，细胞呈多边形，细胞核圆形，细胞边界清晰，与支持细胞毫无相似之处。尽管几乎没有精母细胞分化的证据，但前顶体颗粒和小泡的存在、显著的高尔基体、紧密的细胞间连接以及一些没有轴丝发育的中心粒对，再加上没有脂滴或丰富的滑面内质网，支持了精原细胞瘤而非间质细胞瘤的诊断。细胞 S-100 和波形蛋白呈阳性，而细胞角蛋白和甲胎蛋白呈阴性。精原细胞瘤在大鼠中极为罕见；这是该品系中的首例报告，也是对无精母细胞分化的大鼠精原细胞瘤的首次全面分析。
