A challenging case of sporadic melanocytoma of the jugular foramen

Neurochirurgie. 2022 Jul;68(4):453-457. doi: 10.1016/j.neuchi.2021.06.001. Epub 2021 Jun 19.

Abstract

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.

Keywords: DNA methylation arrays; Extra-dural neural axis aompartment; Jugular foramen; Melanocytic tumours; Melanocytoma; Next generation sequencing; Skull base.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Female
  • Humans
  • Jugular Foramina*
  • Magnetic Resonance Imaging
  • Meningeal Neoplasms* / diagnosis
  • Meningeal Neoplasms* / pathology
  • Meningeal Neoplasms* / surgery
  • Middle Aged
  • Neoplasm Recurrence, Local
  • Neurilemmoma* / surgery
  • Skull Base Neoplasms* / diagnosis
  • Skull Base Neoplasms* / surgery