Department of Neurological Surgery, University of Washington, Seattle, Washington, USA.
Elson S. Floyd College of Medicine, Washington State University, Everett, Washington, USA.
Oper Neurosurg (Hagerstown). 2022 Aug 1;23(2):e139-e142. doi: 10.1227/ons.0000000000000267. Epub 2022 May 11.
Primary intracranial malignant melanomas (PIMMs) are quite rare, comprising 1% of melanomas and 0.07% of intracranial tumors. PIMMs have been reported in a variety of intracranial locations, but there has only been 1 reported instance of PIMM occurring in the brainstem. In this study, we describe the second reported case of primary pontine malignant melanoma and its treatment.
A 40-year-old man presented with right hemiparesis, diplopia, and dysarthria. MRI demonstrated a hemorrhagic, expansile, and heterogeneously enhancing lesion in the left pons with edema extending to the left thalamus and posterior limb of the internal capsule. Surgical resection was performed through a transpetrosal approach. Pathology resulted as malignant melanoma immunopositive for BRAF V600E mutation. Complete oncological workup revealed no other lesions; thus, he was diagnosed with PIMM of the brainstem.
We report a rare case of primary pontine malignant melanoma in which microsurgical resection resulted in dramatic clinical improvement despite the challenging location. This is only the second reported case of brainstem PIMM. More patients with longer-term follow-up will be necessary to determine the best treatment approach.
原发性颅内恶性黑色素瘤（PIMM）非常罕见，占黑色素瘤的 1%，占颅内肿瘤的 0.07%。PIMM 已在多种颅内位置报道，但仅有 1 例报告发生在脑干。本研究描述了第二例原发性脑桥恶性黑色素瘤及其治疗方法。
一名 40 岁男性出现右侧偏瘫、复视和构音障碍。MRI 显示左侧脑桥内有出血性、扩张性和不均匀强化病变，水肿延伸至左侧丘脑和内囊后肢。通过经岩骨入路进行了手术切除。病理结果为恶性黑色素瘤，BRAF V600E 突变免疫阳性。全面的肿瘤学检查未发现其他病变；因此，他被诊断为脑干原发性恶性黑色素瘤。
我们报告了一例罕见的原发性脑桥恶性黑色素瘤病例，尽管位置具有挑战性，但显微镜下切除导致了显著的临床改善。这是第二个报告的脑干 PIMM 病例。需要更多具有长期随访的患者来确定最佳治疗方法。
