病例3
患者基本信息：患者男性,41岁,颅骨多发病灶,多饮、多尿
检查方法：MRI
影像特征：
图1 T1WI冠状位显示下丘脑占位，呈等信号影
图2 T1WI矢状位显示下丘脑、漏斗区占位呈等信号影，垂体后叶正常短T1信号影消失
图3 T1WI矢状位显示占位明显强化，占位下方垂体柄纤细
图4 T1WI显示颅底异常信号影，累及枕骨及右侧咽旁间隙
拟诊：朗格汉斯细胞组织细胞增生症（langerhans cell histiocytosis）
诊断要点：朗格汉斯细胞组织细胞增生症常见于儿童，也可见于成年人，是全身性疾病，约16%的患者可见中枢神经系统受累，但仅表现为中枢神经系统受累的患者较少。颅内表现通常为下丘脑、垂体柄受累，临床常有中枢性尿崩、生长激素缺乏的表现。增强后明显强化，垂体后叶短T1信号影消失。一些病例中还可见视交叉受累。
Diagnosis: langerhans cell tissue hyperplasia is common in children, also seen in adults, is a systemic disease, about 16% of the patients is the central nervous system involvement, but only less performance for patients with central nervous system involvement. Intracranial performance usually in the hypothalamus, pituitary stalk involvement, clinical common central urine collapse, lack of growth hormone. Obvious enhancement, posterior lobe short T1 signal the shadow disappear. Some cases of optic chiasma involvement are visible.
鉴别诊断：
1、生殖细胞瘤：除累及垂体柄造成垂体柄增厚外，可侵及垂体，表现为垂体增大，后叶为主，有时这2种疾病难以鉴别，依赖于其他临床检查及随访观察病变变化等分析判断。
2、垂体炎：可见侵及前叶，表现为垂体增大，激素冲击治疗后体检缩小。
3、淋巴瘤：单独下丘脑、垂体柄受累少见。
病例4
患者基本信息：患者女性，16岁，身材矮小
检查方法：MRI
影像特征：
图1 T1WI冠状位显示垂体柄增粗，均匀等信号影图2 T1WI矢状位显示垂体柄增粗，均匀等信号影，垂体后叶短T1信号消失
图3 T2WI冠状位显示病灶亦呈等信号
图4 增强T1WI矢状位显示鞍内至下丘脑病变呈明显均匀强化
拟诊：鞍区生殖细胞瘤（Saddle area germ cell tumors）
诊断要点：颅内生殖细胞瘤最常见于松果体区，其次为鞍上池或垂体窝。生殖细胞瘤是生殖细胞起源的肿瘤中常见的一种类型。鞍上的生殖细胞瘤可以是松果体区肿瘤的转移灶，或原发于鞍上池，男女发病率相同，而松果体区生殖细胞瘤常见与男性，发病年龄多在10-30岁，表现为尿崩、视力障碍或垂体功能减退。影像学表现为局限性占位，可局限性浸润，在MR T1WI、T2WI上表现为等信号影，或T2WI呈稍高信号影，通常明显强化。病变易出血，常见囊变，但钙化少见。对放射治疗敏感。
Diagnosis: intracranial germ cell tumors of the most common in pineal region, followed by saddle pool or pituitary fossa. Germ cell tumors is the origin of germ cell tumor in a common type. Saddle of germ cell tumors can be pineal region tumor metastases, or primary pools on the saddle, incidence of a disease for men and women the same, while common with male germ cell tumors, pineal region onset ages 10 to 30 years old, and in more urine collapse for the performance of visual impairment or pituitary function decline. Imaging findings of limitations placeholder, but localized infiltration, on MR T1WI, T2WI manifestation for signal, or T2WI was slightly higher signal, usually significantly improved. Lesions prone to bleeding, common cystic change, but calcification is rare. Sensitive to radiation therapy.
鉴别诊断：
1、朗格汉斯细胞组织增生症：试验性放射治疗不敏感，可见其他颅骨侵犯的病灶。
2、下丘脑视路胶质瘤：起自视路或下丘脑，通常在T2WI上信号较高。
