Zhang Hui, Qi Song-Tao, Fan Jun, Fang Lu-Xiong, Qiu Bing-Hui, Liu Yi, Qiu Xiao-Yu
Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
J Clin Neurosci. 2016 Dec;34:151-157. doi: 10.1016/j.jocn.2016.06.009. Epub 2016 Jul 28.
Whether bifocal germinomas (BFGs) synchronously presenting within the pineal region and the hypothalamo-neurohypophyseal axis (HNA) are primary germinomas of dual-origin remains to be elucidated. We analyzed MRI images and clinical features of 95 neurohypophyseal germinomas and 21 BFG patients and developed a tentative definition of the BFGs. We found dual-primary BFGs (true BFGs) do exist. The fundamental difference between primary and metastatic HNA germinomas was the direction of tumor growth. For a true BFG, the primary HNA tumor grew from the neurohypophysis toward the hypothalamus and almost invaded the whole pituitary stalk. For a false BFG (primary pineal germinoma with HNA metastasis), the metastatic HNA tumor first appeared at the third ventricular floor (TVF), grew toward the neurohypophysis, but commonly did not invade the inferior pituitary stalk. Compared to false BFGs, true BFGs commonly had diabetes insipidus as the first symptom, dysfunction of the anterior pituitary, no high-intensity MRI signal at the posterior pituitary, a larger extension of the HNA tumor, and fewer numbers of remote lesions from cerebrospinal fluid seeding. Accordingly, 12.8% (12/96) of our germinoma patients had true BFGs, and of these, 58.3% (7/12) were free of remote metastases and warranted treatment with limited radiotherapy. True BFGs with remote metastases and all false BFGs should be treated with craniospinal irradiation. We provided evidence for the diagnosis of true BFGs that is useful for radiotherapy strategy, suggesting that the existence of metastasis to other locations is not a diagnostic criterion for a true BFG.
松果体区和下丘脑 - 神经垂体轴（HNA）同步出现的双灶性生殖细胞瘤（BFGs）是否为双原发起源的原发性生殖细胞瘤仍有待阐明。我们分析了95例神经垂体生殖细胞瘤和21例BFG患者的MRI图像及临床特征，并制定了BFGs的初步定义。我们发现双原发BFGs（真性BFGs）确实存在。原发性和转移性HNA生殖细胞瘤的根本区别在于肿瘤生长方向。对于真性BFG，原发性HNA肿瘤从神经垂体向下丘脑生长，几乎侵犯整个垂体柄。对于假性BFG（原发性松果体生殖细胞瘤伴HNA转移），转移性HNA肿瘤首先出现在第三脑室底部（TVF），向神经垂体生长，但通常不侵犯垂体柄下部。与假性BFG相比，真性BFG通常以尿崩症为首发症状，垂体前叶功能障碍，垂体后叶在MRI上无高强度信号，HNA肿瘤范围更大，脑脊液播散导致的远处病灶数量更少。因此，我们的生殖细胞瘤患者中有12.8%（12/96）为真性BFG，其中58.3%（7/12）无远处转移，可采用有限放疗。有远处转移的真性BFG和所有假性BFG均应采用全脑全脊髓照射治疗。我们为真性BFG的诊断提供了对放疗策略有用的证据，表明转移至其他部位并非真性BFG的诊断标准。
