Takahashi I, Sugimoto S, Nunomura M, Takahashi A, Aida T, Katoh T, Abe H, Kojima H, Inoue K
Department of Neurological Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
No To Shinkei. 1990 Nov;42(11):1031-4.
A case of cystic intracranial metastatic amelanotic melanoma is presented. As far as we know, cyst formation in intracranial melanoma is rare, and only 15 cases of intracranial amelanotic melanoma have been reported until now. A 63-year-old man was admitted with headache and progressive visual disturbance. CT scan revealed a large low-density mass with ring-like enhancement in the left frontal lobe. Both T 1-and T 2-weighted MRI images revealed hyperintensity. A left frontotemporal craniotomy was performed. A yellowish mass was observed in the frontal lobe. The content of the cyst consisted of old hematoma, xanthochromic fluid and necrotic tissue, was evacuated and the cyst wall was totally resected. No abnormal pigmentation was noted in the cyst wall and surrounding brain tissue. The histological examination revealed amelanotic melanoma. Primary lesion was found on the left thigh later and resected. The patient died of further intracranial metastasis with repeated hemorrhage 5 months after the admission. Both CT and MRI findings of our case is atypical as an intracranial malignant melanoma. However, these are compatible with those of intracerebral hemorrhage in subacute stage. It is suggested that melanoma may make the diagnosis difficult when tumor hemorrhage modifies the images of CT or MRI.
本文报告一例囊性颅内转移性无色素性黑色素瘤病例。据我们所知，颅内黑色素瘤形成囊肿较为罕见，迄今为止仅报道过15例颅内无色素性黑色素瘤。一名63岁男性因头痛和进行性视力障碍入院。CT扫描显示左额叶有一个大的低密度肿块，呈环状强化。T1加权和T2加权MRI图像均显示高信号。进行了左额颞开颅手术。在额叶观察到一个淡黄色肿块。囊肿内容物由陈旧性血肿、黄变液和坏死组织组成，予以清除，囊肿壁完全切除。囊肿壁和周围脑组织未发现异常色素沉着。组织学检查显示为无色素性黑色素瘤。随后在左大腿发现原发性病变并切除。患者入院5个月后因颅内进一步转移并反复出血死亡。我们病例的CT和MRI表现作为颅内恶性黑色素瘤是非典型的。然而，这些表现与亚急性期脑出血的表现相符。提示当肿瘤出血改变CT或MRI图像时，黑色素瘤可能会使诊断变得困难。
