Kinoshita Yasuyuki, Tominaga Atsushi, Usui Satoshi, Kurisu Kaoru
Department of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
Surg Neurol Int. 2014 Aug 20;5:128. doi: 10.4103/2152-7806.139377. eCollection 2014.
It has not been reported previously that the solid enhancing portion of a craniopharyngioma has involuted without a change in cyst size.
We herein report a case of a craniopharyngioma with spontaneous involution of a solid gadolinium (Gd)-enhanced region on magnetic resonance imaging (MRI). A 44-year-old female was referred to our department with a mass on MRI associated with headaches and polyuria. The images showed a suprasellar cystic lesion progressing from the posterior pituitary lobe to the right hypothalamus along the pituitary stalk. Examinations of the cerebrospinal fluid showed aseptic meningitis and a positive titer of beta-human chorionic gonadotropin (HCG-β) preoperatively. The hypothalamic lesion became enlarged over the following 3 weeks, and a biopsy of the posterior pituitary lobe was performed via the endonasal transsphenoidal approach under a preoperative diagnosis of a germ cell tumor (GCT). The histological diagnosis was a craniopharyngioma, and the patient's postoperative findings on MRI were atypical: The solid Gd-enhanced region in the hypothalamus had spontaneously decreased in size and the peritumoral edema had improved, although the biopsy site in the posterior pituitary lobe was distant from the area of shrinkage. We speculated that the involutional portion on MRI mimicking a tumor was actually the normal hypothalamus, which was abnormally enhanced due to a disruption of the blood-brain barrier caused by the craniopharyngioma.
Gd-enhanced regions of parenchyma neighboring the cysts of craniopharyngioma should be carefully managed, taking into consideration the possibility of the enhancement of normal tissue.
此前尚未有颅咽管瘤实性强化部分出现退缩而囊肿大小不变的报道。
我们在此报告一例颅咽管瘤病例，其在磁共振成像（MRI）上实性钆（Gd）强化区域出现自发退缩。一名44岁女性因MRI检查发现肿块并伴有头痛和多尿被转诊至我科。图像显示鞍上囊性病变沿垂体柄从垂体后叶延伸至右侧下丘脑。脑脊液检查显示术前有无菌性脑膜炎且β-人绒毛膜促性腺激素（HCG-β）滴度呈阳性。在接下来的3周内，下丘脑病变增大，在术前诊断为生殖细胞瘤（GCT）的情况下，经鼻蝶窦入路对垂体后叶进行了活检。组织学诊断为颅咽管瘤，患者术后MRI表现不典型：下丘脑实性Gd强化区域大小自发减小，瘤周水肿改善，尽管垂体后叶的活检部位与缩小区域距离较远。我们推测MRI上类似肿瘤的退缩部分实际上是正常下丘脑，由于颅咽管瘤导致血脑屏障破坏而异常强化。
对于颅咽管瘤囊肿邻近实质的Gd强化区域，应考虑到正常组织强化的可能性，谨慎处理。
