Brain Pathol. 2012 Jul;22(4):563-6. doi: 10.1111/j.1750-3639.2012.00604.x.
We present a case of an atypical pituitary adenoma with prominent lymphocyte infiltration and germinal center formation. Histologically, the tumor revealed clusters of large pleomorphic cells with vesicular nuclei, prominent nucleoli, smudgy chromatin, and abundant eosinophilic cytoplasm. There was heavy lymphocyte infiltration and prominent germinal center formation. Mitoses were rare, and the Ki-67 index was 15%. The lymphocytes were composed of both CD3-positive T lymphocytes and CD20-positive B-cells. The diagnosis was atypical pituitary adenoma. Germinal centers have not previously been reported in these tumors. It is important to correlate histology and immunohistochemistry to differentiate this adenoma from other pituitary lesions with prominent lymphocyte infiltration, such as germinoma and lymphocytic hypophysitis.
我们报告一例具有显著淋巴细胞浸润和生发中心形成的非典型垂体腺瘤。组织学上，肿瘤显示出大而异型细胞簇，具有泡状核、显著核仁、模糊染色质和丰富的嗜酸性细胞质。有大量淋巴细胞浸润和明显的生发中心形成。有丝分裂罕见，Ki-67 指数为 15%。淋巴细胞由 CD3 阳性 T 淋巴细胞和 CD20 阳性 B 细胞组成。诊断为非典型垂体腺瘤。以前在这些肿瘤中没有报道过生发中心。重要的是要将组织学和免疫组织化学相结合，将这种腺瘤与其他具有显著淋巴细胞浸润的垂体病变区分开来，例如生殖细胞瘤和淋巴细胞性垂体炎。
