Meningeal melanocytoma [Neurosurgery Wiki]

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====== Meningeal melanocytoma ======

===== Latest Pubmed Related Articles =====

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[[Meninge]]al [[melanocytoma]] is a rare type of tumor that originates from [[melanocyte]]s, which are the pigment-producing cells usually found in the skin and eyes. In some cases, these cells can be found in other parts of the body, including the meninges, which are the protective membranes that surround the brain and spinal cord. When a melanocytoma forms in the meninges, it is referred to as a meningeal melanocytoma.

Here are some key points about meningeal melanocytomas:

Rare Occurrence: Meningeal melanocytomas are considered rare tumors. They account for only a small percentage of all central nervous system tumors.

Benign Nature: Meningeal melanocytomas are typically benign (non-cancerous) tumors, which means they do not spread to other parts of the body (metastasize). However, they can cause symptoms by compressing nearby brain or spinal cord structures.

Location: These tumors are most commonly found along the base of the skull or in the spinal cord, although they can occur in other parts of the central nervous system.

Symptoms: The symptoms of meningeal melanocytomas can vary depending on their location and size. Common symptoms may include headaches, seizures, changes in vision, and neurological deficits such as weakness or numbness.

Diagnosis: Diagnosis is typically made through a combination of imaging studies, such as MRI or CT scans, and a biopsy to confirm the presence of melanocytic cells.

Treatment: Treatment of meningeal melanocytomas often involves surgical removal of the tumor, which can provide both diagnostic information and symptom relief. If the tumor is completely resected, it may not recur. However, in some cases, additional treatment such as radiation therapy may be considered.

Prognosis: The prognosis for meningeal melanocytoma is generally good when the tumor is benign and can be completely removed. The long-term outcome can be excellent, with a low likelihood of recurrence.
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[[Meningeal Melanocytoma]] can occur along the neural axis most commonly in [[posterior fossa]], adjacent to the cranial nerve nuclei, and [[Meckel's cave]] and in the foramen magnum. Within the spine, it present as intradural extramedullary masses, mostly found in the upper cervical region, as the melanocytes are most concentrated in this region.
These tumours can be both intra-/extradural and intra-/extramedullary
((Horn EM, Nakaji P, Coons SW, Dickman CA. Surgical treatment for intramedullary spinal cord melanocytomas. J Neurosurg Spine. 2008 Jul;9(1):48-54. doi: 10.3171/SPI/2008/9/7/048. PMID: 18590410.)).

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[[Meningeal Melanocytoma]] were first described in [[1972]] by Limas and Tio as primary melanotic tumours of the [[leptomeninge]]s 
((Limas C, Tio FO. Meningeal melanocytoma ("melanotic meningioma"). Its melanocytic origin as revealed by electron microscopy. Cancer. 1972 Nov;30(5):1286-94. doi: 10.1002/1097-0142(197211)30:5<1286::aid-cncr2820300522>3.0.co;2-v. PMID: 4343293.))
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===== Classification =====

[[Intracranial Meningeal Melanocytoma]]

[[Spinal Meningeal Melanocytoma]]

===== Clinical features =====
They can present as diffuse disseminations within the subarachnoid spaces, space occupying solid masses within the central nervous system. They present as slowly growing mass lesions with focal neurological deficits due to the mass effect on the adjacent tissues
((Brat D. J. Melanocytic neoplasms of the central nervous system. In: Perry A., Brat D. J., editors. Practical Surgical Neuropathology: A Diagnostic Approach. Philadelphia, Pa, USA: Churchill Livingstone; 2010. pp. 353–359.))
===== Differential diagnosis =====

[[Melanocytic tumor]]s may be secondary to [[melanoma]] or be histologically benign, however, their diffuse nature makes them impossible to cure. [[Melanocytosis]] is a diffuse tumour that can form solitary extra-axial tumours, which invades the parenchyma and presents signs of malignancy with increased [[mitosis]] and [[Ki67]], observed in 1 to 6% of immunopathological exams. [[Melanoma]] of the leptomeninges, presents signs of malignancy with anaplastic cells, which cluster in fascicles of [[melanin]] in the cytoplasm, with more than 3 atypical mitoses per field and Ki67 presenting in more than 6% of the immunopathological fields analysed
((Padilla-Vázquez F, Escobar-de la Garma VH, Ayala-Arcipreste A, Mendizábal-Guerra R, Cuesta-Mejía T. Melanocitoma y melanomatosis meníngea, lesiones similares pero diferentes [Melanocytoma and meningeal melanocytosis, similar but different lesions]. Cir Cir. 2017 May-Jun;85(3):273-278. Spanish. doi: 10.1016/j.circir.2016.11.006. Epub 2017 Jan 23. PMID: 28126183.)).

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[[Meningeal melanomatosis]] is an infrequent tumor originating from the melanocytes in the leptomeninges and one of the recognized primary melanocytic tumors of the central nervous system. The average survival has known to be about 5 months. It can be associated with solid tumors, such as meningeal melanocytomas
((Ramos AA, Ferrara P, Fernández VM, Sanchez CR, Alvarez Vega MA. Meningeal Melanomatosis with a Spinal Meningeal Melanocytoma Trigger by an in vitro Fertilization. Neurol India. 2022 Sep-Oct;70(Supplement):S318-S321. doi: 10.4103/0028-3886.360914. PMID: 36412389.)).
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[[Meningeal melanomatosis]] is an extra-axial well-encapsulated malignant tumour with diffuse meningeal growth and dark coloration (due to high melanin contents), while meningeal melanocytoma is the focalized benign variant. Melanocytic lesions may be secondary to melanoma or be histologically benign, however, their diffuse nature makes them impossible to cure. Melanocytosis is a diffuse tumour that can form solitary extra-axial tumours, which invades the parenchyma and presents signs of malignancy with increased mitosis and Ki67, observed in 1 to 6% of immunopathological exams. Melanoma of the leptomeninges, presents signs of malignancy with anaplastic cells, which cluster in fascicles of melanin in the cytoplasm, with more than 3 atypical mitoses per field and Ki67 presenting in more than 6% of the immunopathological fields analysed
((Padilla-Vázquez F, Escobar-de la Garma VH, Ayala-Arcipreste A, Mendizábal-Guerra R, Cuesta-Mejía T. Melanocitoma y melanomatosis meníngea, lesiones similares pero diferentes [Melanocytoma and meningeal melanocytosis, similar but different lesions]. Cir Cir. 2017 May-Jun;85(3):273-278. Spanish. doi: 10.1016/j.circir.2016.11.006. Epub 2017 Jan 23. PMID: 28126183.))
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A preoperative differential of spinal meningeal melanocytomas is challenging due to their non-specific clinical and neurological presentations
((Srirama Jayamma S, Sud S, Buxi T, Madan VS, Goyal A, Dhawan S. Cervical Spinal Meningeal Melanocytoma Presenting as Intracranial Superficial Siderosis. Case Rep Radiol. 2015;2015:674868. doi: 10.1155/2015/674868. Epub 2015 Dec 7. PMID: 26770862; PMCID: PMC4685124.))

===== Treatment =====
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
((Ricchizzi S, Gallus M, Stummer W, Holling M. How Should We Treat Meningeal Melanocytoma? A Retrospective Analysis of Potential Treatment Strategies. Cancers (Basel). 2022 Nov 27;14(23):5851. doi: 10.3390/cancers14235851. PMID: 36497333; PMCID: PMC9738837.)). 

===== Outcome =====

Malignant transformation was described in 18 patients. Of these, 11 patients developed metastasis
((Ricchizzi S, Gallus M, Stummer W, Holling M. How Should We Treat Meningeal Melanocytoma? A Retrospective Analysis of Potential Treatment Strategies. Cancers (Basel). 2022 Nov 27;14(23):5851. doi: 10.3390/cancers14235851. PMID: 36497333; PMCID: PMC9738837.))
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They typically behave as slow-growing, well-circumscribed tumours in the spinal cord, however, can also be found in the brain
((Horn EM, Nakaji P, Coons SW, Dickman CA. Surgical treatment for intramedullary spinal cord melanocytomas. J Neurosurg Spine. 2008 Jul;9(1):48-54. doi: 10.3171/SPI/2008/9/7/048. PMID: 18590410.)).
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These tumors have better prognosis than their malignant counterparts
((Painter TJ, Chaljub G, Sethi R, Singh H, Gelman B. Intracranial and intraspinal meningeal melanocytosis. AJNR Am J Neuroradiol. 2000 Aug;21(7):1349-53. PMID: 10954294; PMCID: PMC8174895.)).

===== Literature review =====
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.

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.

Ricchizzi 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
((Ricchizzi S, Gallus M, Stummer W, Holling M. How Should We Treat Meningeal Melanocytoma? A Retrospective Analysis of Potential Treatment Strategies. Cancers (Basel). 2022 Nov 27;14(23):5851. doi: 10.3390/cancers14235851. PMID: 36497333; PMCID: PMC9738837.))
===== Case reports =====

==== 2023 ====

Intermediate grade meningeal melanocytoma of the posterior fossa, GNAQ mutation-positive
((Daoud L, Gunes Tatar I, Raftopoulos C, Lammens M. Intermediate grade meningeal melanocytoma of the posterior fossa, GNAQ mutation-positive. Acta Neurol Belg. 2023 Jun 14. doi: 10.1007/s13760-023-02298-8. Epub ahead of print. PMID: 37314637.)).





==== 2017 ====

Padilla-Vázquez et al. present the case of a patient with long-term meningeal melanomatosis, with progressive neurologic deficit and characteristic radiologic features, and another case of meningeal melanocytoma.

Benign melanocytic neoplasms of the central nervous system must be treated aggressively in the early phases with strict follow-up to avoid progression to advanced phases that do not respond to any treatment method. Unfortunately, the prognosis for malignant melanocytic lesions is very poor irrespective of the method of treatment given
((Padilla-Vázquez F, Escobar-de la Garma VH, Ayala-Arcipreste A, Mendizábal-Guerra R, Cuesta-Mejía T. Melanocitoma y melanomatosis meníngea, lesiones similares pero diferentes [Melanocytoma and meningeal melanocytosis, similar but different lesions]. Cir Cir. 2017 May-Jun;85(3):273-278. Spanish. doi: 10.1016/j.circir.2016.11.006. Epub 2017 Jan 23. PMID: 28126183.)).

==== 2015 ====

A 21-year-old man with a previous history of recurrent lipothymia was admitted to the emergency department because of generalized seizures. Death occurred despite resuscitation. A medico-legal autopsy was performed. External examination of the body showed nonspecific asphyxia signs without any violence evidence. Necropsy noticed a brain edema with a dark color of the meninges especially in the frontal part. Histological examination concluded to diffuse meningeal melanocytoma with cerebral edema
((Aissaoui A, Mosrati MA, Moussa A, Belhaj M, Bougattas M, Zakhama A, Chadly A. Sudden Death and Primary Leptomeningeal Melanocytosis: A Case Report With an Autopsy Diagnosis. Am J Forensic Med Pathol. 2015 Sep;36(3):199-201. doi: 10.1097/PAF.0000000000000161. PMID: 26266890.)).
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A 31-year-old woman presenting with a 2-year history of amenorrhea and an intrasellar mass with suprasellar extension, suggestive of hemorrhagic pituitary neuroendocrine tumor.

Transsphenoidal surgical excision was difficult due to extensive bleeding from the lesion, and at the time, the tumor could not be diagnosed histopathologically. Six years later, Sakata et al. operated again because of tumor regrowth. Angiography revealed a hypervascular tumor, which was fed from the dorsal sellar floor. We had difficulty resecting the tumor, but achieved total removal. These case had typical radiographic characteristics of melanocytoma, revealed by both magnetic resonance imaging and angiography. However, it was difficult to reach a final diagnosis. Further histopathological examination, including immunohistochemical and ultrastructural studies, was helpful for diagnosis of melanocytoma.

Primary sellar melanocytic tumors are derived from melanocytes in the meningeal lining of the sellar floor or in the diaphragm sellae, based on both embryological assumptions and the clinical findings of these case
((Sakata K, Miyoshi J, Takeshige N, Komaki S, Miyagi N, Nakashima S, Morioka M, 
Sugita Y. Primary meningeal melanocytoma of the sellar region: review of the
literature and differential diagnosis with special reference to angiographical
features. Pituitary. 2015 Jan 13. [Epub ahead of print] PubMed PMID: 25583147.)).

==== 2011 ====
Meningeal melanocytoma with malignant behaviour
((Ayuga Loro F, Díez De Valle R, Casado López RM, Florensa Vila J. Melanocitoma meníngeo con comportamiento maligno [Meningeal melanocytoma with malignant behaviour]. Neurologia. 2011 Nov;26(9):565-6. Spanish. doi: 10.1016/j.nrl.2011.01.023. Epub 2011 Apr 6. PMID: 21474212.))

===== References =====