中央尿崩症（CDI）是一种罕见的疾病，由各种潜在疾病引起，包括肿瘤、自身免疫性疾病和浸润性疾病。鉴别CDI的病因是困难的。曾一度被归类为“特发性”中央尿崩症可能实际上潜在着至今不太了解的各种发病机制和或在初始表现上并不明显的病理机制。因此，即使在起病时被诊断为特发性CDI，监测过程中也常见出现诸如生殖细胞瘤之类的肿瘤。关键是，延误对生殖细胞瘤的诊断可能与预后较差有关。最近，发现抗r抗体-3A抗体的存在被认为是淋巴细胞梗阻-神经下垂体炎自身免疫介导的CDI的高度敏感和特异性标志。在这里，我们介绍了两例名为患者1的13岁男孩和患者2的19岁年轻男子，他们被诊断为特发性CDI。在两位患者中，发生了全垂体功能低下。磁共振成像显示，在CDI发病大约1年半后，垂体柄增粗和垂体肿胀。西方印迹分析未发现患者血清中抗r抗体-3A的存在，表明可能不存在自身免疫机制的参与。随后，两位患者均被诊断为生殖细胞瘤。他们接受了化疗，随后是放疗。值得注意的是，在患者2中，睾酮和胰岛素样生长因子-1水平恢复正常，并在化疗放疗后恢复了性欲和胡须生长。我们的数据表明，在临床诊断为特发性CDI的年轻患者中，抗r抗体-3A抗体的缺乏可能增加非淋巴细胞病变（包括生殖细胞瘤）的发生概率。因此，我们建议在这些疾病的起始阶段采用更加谨慎的方法。©2023。作者。

Central diabetes insipidus (CDI) is a rare condition caused by various underlying diseases, including neoplasms, autoimmune diseases, and infiltrative diseases. Differentiating between CDI etiologies is difficult. What has initially been classified as "idiopathic" central diabetes insipidus might in fact underlie various pathogenic mechanisms that are less understood to date and/or are not obvious at initial presentation. Therefore, even if idiopathic CDI is diagnosed at the time of onset, it is common for tumors such as germinoma to develop during surveillance. Crucially, a delayed diagnosis of germinoma may be associated with a worse prognosis. Recently, the presence of anti-rabphilin-3A antibodies has been found to be a highly sensitive and specific marker of lymphocytic infundibuloneurohypophysitis, an autoimmune-mediated CDI.We herein present two cases, namely, a 13-year-old boy (patient 1) and a 19-year-old young man (patient 2) who were diagnosed with idiopathic CDI. In both patients, panhypopituitarism developed. Magnetic resonance imaging revealed pituitary stalk thickening and pituitary swelling approximately 1 1/2 years after the onset of CDI. Western blotting did not reveal the presence of anti-rabphilin-3A antibodies in serum in either patient, suggesting that autoimmune mechanisms might not be involved. Both patients were subsequently diagnosed with germinoma on pathological examination. They received chemotherapy, followed by radiation therapy. Notably, testosterone and insulin-like growth factor-1 levels normalized, and libido and beard growth recovered after chemoradiotherapy in patient 2.Our data suggest that the absence of anti-rabphilin-3A antibodies in young patients clinically diagnosed with idiopathic CDI may increase the probability of the development of non-lymphocytic lesions, including germinoma. We thus recommend a more attentive approach at the onset of these diseases.© 2023. The Author(s).