Background

The jugular foramen (JF) can be the site of several tumours. Paragangliomas, schwannomas and meningiomas are the most commonly reported. We describe a case of melanocytoma originating from the JF and presenting with an accessory nerve palsy.

Illustrative case

A 48-year-old woman presented with a 6-month history of cervical and left shoulder pain with wasting and weakness of the left trapezius. A Magnetic Resonance Imaging (MRI) showed a T1-hyperintense, T2-isointense, heterogeneously enhancing lesion involving the left JF and extending into the cerebello-medullary and cerebello-pontine cisterns. A retrosigmoid craniotomy was performed and a near-total removal achieved. The accessory nerve was involved by tumour and could not be preserved. Given the diagnostic uncertainty between melanotic schwannoma, metastatic melanoma and meningeal melanocytoma, next generation sequencing and genome-wide DNA methylation arrays were performed, documenting a mutation in GNA11 (c.6226A>T, p. Gln209Leu) and a methylation profile consistent with melanocytoma. The patient underwent adjuvant fractionated radiotherapy of the tumour remnant. A follow-up MRI 4 years after surgery did not show any tumour recurrence.

Conclusions

The differential diagnosis of skull base pigmented tumours can be challenging, particularly when they occur in unusual locations such as the JF. They can be misdiagnosed given their similar clinical, neuroradiological and pathological features if anatomy of the site of origin is not carefully considered and molecular tests are not performed, leading to erroneous treatment and follow-up planning.

中文翻译：

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颈静脉孔散发性黑色素细胞瘤一例具有挑战性的病例

背景

颈静脉孔（JF）可以是几个肿瘤的部位。副神经节瘤、神经鞘瘤和脑膜瘤是最常见的报道。我们描述了一个起源于 JF 并表现为副神经麻痹的黑色素细胞瘤病例。

说明性案例

一名 48 岁的女性，因左侧斜方肌萎缩和无力而出现颈部和左肩部疼痛 6 个月。磁共振成像 (MRI) 显示 T1 高信号、T2 等信号、不均匀增强的病变，累及左侧 JF，并延伸到小脑-延髓池和小脑-桥脑池。进行了乙状窦后开颅手术，几乎完全切除。副神经被肿瘤累及，无法保留。鉴于黑色素神经鞘瘤、转移性黑色素瘤和脑膜黑色素细胞瘤之间的诊断不确定性，进行了下一代测序和全基因组 DNA 甲基化阵列，记录了GNA11中的突变(c.6226A>T, p. Gln209Leu) 和与黑素细胞瘤一致的甲基化谱。患者接受了肿瘤残余的辅助分割放射治疗。术后 4 年的 MRI 随访未显示任何肿瘤复发。

结论

颅底色素性肿瘤的鉴别诊断可能具有挑战性，特别是当它们发生在不寻常的位置时，例如 JF。如果未仔细考虑起源部位的解剖结构并且未进行分子检测，则可能由于其相似的临床、神经放射学和病理学特征而被误诊，从而导致错误的治疗和随访计划。