MR imaging findings of the intraspinal meningeal melanocytoma: correlation with histopathologic findings

Meningeal melanocytoma of the central nervous system in children

PURPOSE

This study aimed to summarize the existing English-language literature on central nervous system (CNS) meningeal melanocytomas in children, and additionally describe our institutional case report.

METHODS

PubMed database was screened on September 2, 2024, for English-language papers reporting on pediatric patients with CNS meningeal melanocytoma.

RESULTS

A total of 17 papers reporting on 18 patients with 19 CNS meningeal melanocytomas were found in the literature. Additionally, we reported on a 15-year-old male patient with C2-C6 meningeal melanocytoma. Pediatric cohort analysis showed nearly equal sex distribution and a mean age at diagnosis of 11.9 years. There were fifteen intracranial (75%) and five spinal tumors (25%). Four lesions (20%) were diagnosed as intermediate-grade melanocytomas, while the remaining sixteen (80%) were benign meningeal melanocytomas. Most tumors were hyperintense on T1-weighted imaging (85%) and hypointense on T2-weighted imaging (73%). All tumors showed positivity for S100 and Melan-A. Most tumors were characterized by a lack of CNS invasion (91%). Gross-total resection (GTR) was performed in 61% of tumors. Adjuvant radiotherapy (RT) was applied in 50% of patients with incomplete tumor resection. Postoperatively, 62% of patients achieved a favorable outcome. We found 1, 2, 3, and 4-year overall survival of 80%, 71%, 71%, and 50%, respectively. The recurrence rate was 15% after a mean time of 10 months.

CONCLUSIONS

Meningeal melanocytomas constitute a rare subgroup of CNS tumors. Surgical tumor removal aiming at maximally safe GTR remains a standard approach, resulting in favorable postoperative outcomes. Considering high recurrence rate, long-term follow-up is needed.

A rare case of multifocal craniospinal leptomeningeal melanocytoma: A case report and scoping review

Introduction

Leptomeningeal melanocytomas are rare tumours originating from neural crest derived melanocytes. They are usually solitary and presentation with multifocal meningeal melanocytoma is very rare and indicative of potentially more aggressive behaviour. This case report and scoping review sought to evaluate the presentation, and key radiological features that can help differentiate multifocal meningeal melanocytoma from other differentials and provide a discussion of the key management and prognostic points once these tumours are diagnosed.

Case presentation

A 26 year old male presented with neck pain radiating to both shoulders and subjective weakness in left shoulder movement. MRI demonstrated a large enhancing C2-C3 intradural-extramedullary lesion with further lesions at the T7/T8 level, left cerebellopontine angle and midline suprachiasmatic region. Whilst the imaging appearances were initially thought be indicative of a phacomatosis such as NF2-related schwannomatosis, surgical excision of the cervical tumour confirmed a melanocytic tumour of leptomeningeal origin, consistent with multifocal meningeal melanocytoma. Patient made a good post-operative recovery and remains under half yearly radiological surveillance, with repeat MRI 6 months after surgery demonstrating subtle growth of the untreated intracranial and spinal lesions.

Literature review and conclusions

This is the first description, to our knowledge, of a multifocal meningeal melanocytoma associated with both cerebellopontine angle and suprasellar lesions. This case and included scoping review highlight the need to consider this rare diagnosis whenever multifocal craniospinal lesions are encountered, and the need to consider aggressive management through surgical resection and adjuvant craniospinal radiotherapy once these tumours are diagnosed.

How Should We Treat Meningeal Melanocytoma? A Retrospective Analysis of Potential Treatment Strategies

BACKGROUND

Meningeal melanocytomas (MM) are rare primary melanocytic tumors of the leptomeninges with an incidence of 1:10,000,000. Until now, there has been only sparse information about this tumor entity. Here, we provide a meta-analysis of all cases published in the English language since 1972.

METHODS

A literature review was performed using PubMed and Web of Science. All published cases were evaluated for location, sex, age, therapeutic approach, and outcome. In total, we included 201 patient cases in our meta-analysis.

RESULTS

The majority of MM was diagnosed more frequently in men between the third and fifth decade of life. Surgery is the preferred therapeutic approach, and total resection is associated with the best outcome. Patients with partial resection or tumor recurrence benefit from adjuvant radiotherapy, whereas chemo- or immunotherapies do not improve the disease course. Malignant transformation was described in 18 patients. Of these, 11 patients developed metastasis.

CONCLUSIONS

We present the first retrospective meta-analysis of all MM cases published in the English language, including an evaluation of different treatment strategies allowing us to suggest a novel treatment guideline highlighting the importance of total resection for recurrence-free survival and characterizing those cases which benefit from adjuvant radiotherapy.

Malignant Transformation and Metastatic Spread of Dumbbell-Shaped Meningeal Melanocytoma of the Cervical Spine: A Case Report and Literature Review

Background

Meningeal melanocytoma is a rare disease that originates from leptomeningeal melanocytes in the central nervous system. Meningeal melanocytoma is generally considered benign, and has a good prognosis following complete surgical resection. Reports of the malignant transformation and spread of these tumors are scarce.

Case Presentation

A 19 year old female presented with headache, progressive limb weakness, and dyspnea. Magnetic resonance imaging showed a dumbbell-shaped lesion at C1–C2 that was hyperintense on T1 weighted images and showed strong contrast enhancement. Total resection was achieved using a posterior midline approach. Post-operative pathology showed meningeal melanocytoma. The tumor recurred 9 months later with intracranial spread. Resection of the lesion revealed malignant transformation to meningeal melanoma.

Conclusion

Meningeal melanocytoma harbors malignant potential even with total resection. Radiotherapy could be considered to prevent disease recurrence and progression.

C6-T1 Intradural Extramedullary Ventral Meningeal Melanocytoma Resected Via Anterior Corpectomy with Reconstruction

BACKGROUND

Melanocytic lesions of the nervous system are thought to arise from leptomeningeal melanocytes, which are derived from neural crest and include diffuse melanocytosis, melanocytomas, and malignant melanomas. Meningeal melanocytomas are extremely rare benign lesions. The usual treatment of intradural extramedullary melanocytomas involves surgical removal through a posterior approach using a laminectomy or laminotomy.

CASE DESCRIPTION

We present a 30-year-old female harboring a C6-T1 ventrally located intradural extramedullary lesion compressing the cord anteriorly. The lesion was totally resected via an anterior approach with oblique corpectomy even if the usual treatment involves surgical removal through a posterior approach using a laminectomy or laminotomy.

CONCLUSIONS

There is no evidence of recurrence at 4-year follow-up records of the patient. We discuss the surgical approach of these rare lesions.

Spinal meningeal melanocytoma in a 5-year-old child: a case report and review of literature

Background

Meningeal melanocytoma is considered a rare lesion arising from leptomeningeal melanocytes. Nearly two thirds of meningeal melanocytomas were reported in the intracranial compartment and the remaining one third in the spine. Spinal melanocytomas can be extradural or intradural, with extradural variant being more common, and the majority of cases have been single reports.

Methods

A 5-year-old male presented with a 4-month history of non-radiating low back pain persistent at rest, with otherwise non-remarkable medical history. The patient was neurologically intact with no deficits. Preoperatively, routine laboratory investigations were non-remarkable. MRI imaging was done and showed a lesion at the level of T11 to L4, hyperintense on T1 and hypointense on T2 with homogenous contrast enhancement. Intraoperatively, the lesion was hemorrhagic, brownish, and rubbery in consistency attached to the ventral dura. Microscopic picture revealed dense cytoplasmic brown melanin pigments, with no significant mitoses or nuclear atypia. What is unique about our case is the age of the patient (5 years).

Results

To the best of our knowledge, after reviewing the literature, this is the youngest case to be reported.

Conclusions

SMM is an extremely rare tumor with a benign course. Complete surgical excision should be attempted. Age of presentation may be as young as in our case and the diagnosis of such a tumor should never be excluded in this early age group with persistent low back ache.

Diagnostic Clue of Meningeal Melanocytoma: Case Report and Review of Literature

In this report, the patient was pre-diagnosed as meningioma before surgery, which turned out to be meningeal melanocytoma. Hence, we will discuss the interpretation of imaging and neurological statuses that may help avoid this problem. A 45-year-old man had increasing pain around the neck 14 months prior to admission. His cervical spine MR imaging revealed a space-occupying, contrast-enhancing mass within the dura at the level of C1. The neurologic examination revealed that the patient had left-sided lower extremity weakness of 4+, decreased sensation on the right side, and hyperreflexia in both legs. Department of Neuroradiology interpreted CT and MR imaging as meningiom. The patient underwent decompression and removal of the mass. We confirmed diagnosis as meningeal melanocytoma through pathologic findings. Afterwards, we reviewed the patient's imaging work-up, which showed typical findings of meningeal melanocytoma. However, it was mistaken as meningioma, since the disease is rare.

Primary scattered multifocal melanocytomas in spinal canal mimicking neurofibromatosis

BACKGROUND CONTEXT

Meningeal melanocytoma is an extremely rare pigmented tumor derived from leptomeningeal melanocytes. By and large, it is considered to be a well-differentiated and slow-growing benign lesion. Generally, meningeal melanocytomas are solitary lesions, and the occurrence of the primary multifocal form in the central nervous system is exceedingly rare; it has been previously reported in only six cases.

PURPOSE

The present report illustrates a 41-year-old woman with primary multifocal meningeal melanocytoma in the spinal canal. Contrary to earlier reports, the tumors presented with a scattered appearance mimicking neurofibromatosis.

STUDY DESIGN

This study is a case report and review of literature.

METHODS

On admission, the cerebral magnetic resonance images of the patient were normal, whereas the spinal magnetic resonance images showed scattered multifocal nodules mimicking neurofibromatosis. Surgical resection of the responsible lesions was scheduled. In addition to this case presentation, relevant previous reports were reviewed, and the challenging diagnosis, management, and prognosis of meningeal melanocytoma are discussed.

RESULTS

Gross total resection of the two largest lesions was achieved, and histopathological examinations confirmed the diagnosis. Despite the benign histopathological findings, the patient had an aggressive clinical course. On follow-up at 18 months after surgery, she succumbed to the disease.

CONCLUSION

Clinicians should be alert to a potential aggressive clinical course of meningeal melanocytoma, despite its benign histopathological nature. Of particular note is multifocality and diffuse leptomeningeal hyperpigmentation, which may suggest a poor prognosis. A combined treatment including surgical resection and adjuvant radiotherapy should be considered, and long-term close follow-up is necessary.