一例Han-Wistar大鼠垂体细胞瘤的病理学分析

Pathologic Diagnosis of a Pituicytoma in a Han-Wistar Rat

在为期两年的致癌试验中发现空白对照组Han-Wistar大鼠出现1例垂体细胞瘤。临床观察及大体剖检未见明显异常。HE染色结果显示,垂体神经部肿瘤组织呈结节状增生,边界清晰,压迫周围正常组织;肿瘤细胞与神经胶质细胞类似,细胞核呈圆形或卵圆形,细胞质丰富呈嗜酸性或空泡状;肿瘤细胞分化良好,细胞多形性不明显,核分裂象可见;部分肿瘤细胞呈假菊形团状排列。免疫组织化学染色结果显示,胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)及S-100蛋白呈阳性。结合HE染色及免疫组织化学染色结果诊断该肿瘤为自发性良性垂体细胞瘤。

A case of pituicytoma was observed in a Han-Wistar rat from the control group of a 2-year carcinogenicity study.No obvious abnormality were found in clinical observation and necropsy.Hematoxylin and Eosin(HE)staining results showed that nodular hyperplasia in the pars nervosa of the pituitary,which was well demarcated and compressed the adjacent normal tissue.The tumor cells were similar to the glial cells with round or oval nuclei,cytoplasm rich in eosinophilic or vacuole.The tumor cells differentiated well,with no obvious cell pleomorphism and visible mitotic figures.Some tumor cells were arranged in a pseudorosette formation.Immunohistochemical staining(IHC)analysis confirmed positive expression of Glial fibrillary acidic protein(GFAP)and S-100 protein.The tumor was diagnosed as the spontaneous benign pituicytoma combining the HE and IHC staining results.