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Updated: Feb 17, 2026
Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors
Published on: September 20, 2016
Intraventricular melanocytoma diagnosis confirmed by gene mutation profile
Ulrich J Knappe1, Iris Tischoff2, Andrea Tannapfel2
1Department of Neurosurgery, Ruhr University Bochum, Johannes Wesling Hospital Minden, Minden, Germany.
Abstract:
Primary leptomeningeal melanocytic tumors (PLMTs) are rare. They usually arise along the spinal cord and at the skull base. Here we report on a patient with a very rare intraventricular melanocytoma. Histologically, a melanocytic tumor was clearly diagnosed. However, to make the uncommon diagnosis of an intraventricular melanocytoma, metastatic melanoma needed to be excluded. Next generation sequencing covering gene mutations that may occur in PLMTs and cutaneous melanoma was performed. The unique gene mutation profile detected, consisting of an activating CYSLTR2 L129Q mutation and EIF1AX G9R mutation and a lack of mutations in genes known to occur in metastatic melanoma (i.e. BRAF or NRAS) confirmed the diagnosis of an intraventricular melanocytoma. This case report is the second intraventricular melanocytoma published to date and demonstrates the value of applying novel genetic assays to make this diagnosis.
Insights
This study details a rare intraventricular melanocytoma, a primary leptomeningeal melanocytic tumor (PLMT). Genetic sequencing confirmed the diagnosis by identifying unique mutations and excluding metastatic melanoma.
Area of Science:
- Neuro-oncology
- Genetics
- Pathology
Background:
- Primary leptomeningeal melanocytic tumors (PLMTs) are rare central nervous system neoplasms.
- These tumors typically occur along the spinal cord and skull base.
- Intraventricular melanocytomas represent an exceptionally rare subtype of PLMT.
Observation:
- A case of intraventricular melanocytoma is presented.
- Diagnosis required exclusion of metastatic melanoma.
- Histopathological examination confirmed a melanocytic tumor.
Findings:
- Next-generation sequencing identified a unique mutation profile.
- Activating CYSLTR2 L129Q and EIF1AX G9R mutations were detected.
- Absence of common metastatic melanoma mutations (BRAF, NRAS) supported the diagnosis.
Implications:
- This case highlights the diagnostic value of advanced genetic assays.
- Accurate diagnosis of intraventricular melanocytoma is crucial for patient management.
- Further research into the genetic landscape of rare CNS melanocytic tumors is warranted.
