Yukawa Hirotsugu, Seki Hirobumi, Sugawara Takayuki, Boku Nagatoshi, Higuchi Hiroshi, Ono Sadahide
Department of Neurosurgery, Iwate Prefectural Central Hospital, Japan.
No Shinkei Geka. 2003 Sep;31(9):1023-8.
A 29-year-old woman presented with a primary meningeal melanocytoma of the left middle fossa manifesting as headache and nausea. Computed tomography (CT) with contrast medium demonstrated a clearly demarcated, homogeneously enhanced high density area surrounded by a cyst in the left temporal lobe. Magnetic resonance (MR) imaging showed the mass as a slightly high signal intensity area on the T1-weighted image and as a low signal intensity area on the T2-weighted image. Cerebral angiography revealed shift of the middle cerebral artery but no tumor stain. The solid part of the tumor had rapidly increased in size with reduction of the cyst 3 months later. Left frontotemporal craniotomy disclosed a clearly demarcated jet-black tumor attached to the dura. The black-colored lesion in the dura and the bone extended to the skull base, so malignant melanoma was a possibility. The solid part of the tumor was gross totally removed, and the dura and the skull bone were preserved. Histological examination of the tumor specimen revealed meningeal melanocytoma. Melanophages were present in the specimen of the black-colored lesion in the dura and the bone, but no neoplastic infiltration was present. The postoperative course was uneventful, and the patient's headache and nausea disappeared. CT and MR imaging taken 1 month later confirmed total removal of the tumor. No recurrence has been observed for 2.5 years after surgery. Preoperative differentiation of meningeal melanocytoma from malignant melanoma is difficult, but the primary goal of therapy is gross total resection of the solid part of the tumor irrespective of tumor type.
一名29岁女性因左侧中颅窝原发性脑膜黑素细胞瘤就诊，表现为头痛和恶心。增强计算机断层扫描（CT）显示左颞叶有一个边界清晰、均匀强化的高密度区域，周围有一个囊肿。磁共振成像（MR）显示该肿块在T1加权图像上为略高信号强度区域，在T2加权图像上为低信号强度区域。脑血管造影显示大脑中动脉移位，但无肿瘤染色。3个月后，肿瘤实体部分迅速增大，囊肿缩小。左额颞开颅手术发现一个边界清晰的 jet - black 肿瘤附着于硬脑膜。硬脑膜和颅骨上的黑色病变延伸至颅底，因此恶性黑色素瘤可能性大。肿瘤实体部分被肉眼全切，硬脑膜和颅骨得以保留。肿瘤标本的组织学检查显示为脑膜黑素细胞瘤。硬脑膜和颅骨上黑色病变的标本中有噬黑素细胞，但无肿瘤浸润。术后过程顺利，患者的头痛和恶心消失。1个月后进行的CT和MR成像证实肿瘤已完全切除。术后2.5年未观察到复发。术前区分脑膜黑素细胞瘤和恶性黑色素瘤很困难，但无论肿瘤类型如何，治疗的主要目标是将肿瘤实体部分肉眼全切。
