Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 2610  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Resource Links
  »  Similar in PUBMED
 »  Search Pubmed for
 »  Search in Google Scholar for
  »  Article in PDF (1,391 KB)
  »  Citation Manager
  »  Access Statistics
  »  Reader Comments
  »  Email Alert *
  »  Add to My List *
* Registration required (free)  

  In this Article
 »  References
 »  Article Figures

 Article Access Statistics
    PDF Downloaded40    
    Comments [Add]    
    Cited by others 3    

Recommend this journal


Table of Contents    
Year : 2017  |  Volume : 65  |  Issue : 6  |  Page : 1427-1428

Advanced magnetic resonance imaging in the diagnosis of primary intracranial malignant melanoma

1 Department of Radiology and Imaging Sciences, Sri Ramachandra University, Chennai, Tamil Nadu, India
2 Department of Neurosurgery, Sri Ramachandra University, Chennai, Tamil Nadu, India
3 Department of Pathology, Sri Ramachandra University, Chennai, Tamil Nadu, India

Date of Web Publication10-Nov-2017

Correspondence Address:
Dr. Rajeswaran Rangasami
Department of Radiology and Imaging Sciences, Sri Ramachandra University, Chennai - 600 116, Tamil Nadu
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.217953

Rights and Permissions

How to cite this article:
Saranya A, Rangasami R, Chandrasekharan A, Krishnamurthy G, Swaminathan R. Advanced magnetic resonance imaging in the diagnosis of primary intracranial malignant melanoma. Neurol India 2017;65:1427-8

How to cite this URL:
Saranya A, Rangasami R, Chandrasekharan A, Krishnamurthy G, Swaminathan R. Advanced magnetic resonance imaging in the diagnosis of primary intracranial malignant melanoma. Neurol India [serial online] 2017 [cited 2023 Jun 5];65:1427-8. Available from:


Melanoma develops from the pigment-containing cells, melanocytes, and typically occurs in the skin. Primary malignant melanoma of the central nervous system (CNS) is rare, accounting for 1% of all melanomas.[1] Most of the melanomatous tumors occur in the meninges covering the base of the brain or spinal cord.[2] To the best of our knowledge, only one case of cavernous sinus melanocytoma has been reported so far.[3]

An 18-year old male patient presented with complaints of headache, multiple episodes of vomiting, difficulty in speech, and right hemiparesis of 3-day duration. Nervous system examination revealed bilateral papilledema, reduced bulk of left masseter and temporalis muscles, decreased sensation over left side of the face, and grade IV weakness of right upper and lower limbs. Magnetic resonance (MR) examination of the brain revealed a dumbbell shaped mass of size 4.0 × 3.1 × 3.2cm with solid and cystic components in the left cavernous sinus and extending into the posterior fossa. The lesion appeared predominantly mildly hyperintense on T1 and T2-weighted images [Figure 1]a and [Figure 1]b. Hemorrhage was seen in the posterior aspect of the mass [Figure 1]c. The posterior component was seen to extend upto the left cerebellopotine angle causing compression on the brainstem. MR perfusion (using T2 dynamic susceptibility contrast-enhanced perfusion technique) revealed that relative cerebral blood volume of the tumor was 2.4 times that of the normal brain parenchyma [Figure 1]d. Heterogeneous enhancement was seen following contrast administration [Figure 1]e and [Figure 1]f. Initial MR spectroscopy (MRS) of the tumor was interpreted as increased choline (Cho) and reduced N-acety aspartate (NAA) with Cho/NAA ratio of 1.13 with a large lipid lactate peak (1.32ppm). Retrospective re-analysis revealed additional peaks corresponding to taurine (3.4ppm), lysine (1.73ppm), and glutamine–glutamate (2.4ppm) [Figure 2]a and [Figure 2]b. The left trigeminal nerve was not seen separately from the mass. An imaging diagnosis of Vth nerve schwannoma was made.
Figure 1: (a) Axial T1-; and, (b) T2-weighted MR images show a mass in the left cavernous sinus mildly hyperintense to gray matter (arrow). Patchy bright hyperintense areas are seen in the anterior aspect of the mass (open arrow). (c) Axial gradient images show blooming in the posterior part of the mass (broken arrow). (d) Axial perfusion image shows increased perfusion (arrow head). (e and f) Postcontrast T1 images show a strong enhancement in the mass (curved arrow)

Click here to view
Figure 2: (a and b) MR spectroscopy with voxel within the mass shows amino acid peaks (arrows), a large lipid lactate peak besides a cho/NAA ratio of 1.13

Click here to view

At surgery, the covering of the lesion had blackish discoloration. Owing to extensive vascularity and adherence to brainstem, only partial excision and internal decompression of the tumor was done. On microscopy, the cells showed brown-black pigmentation. The tumor cells showed strong positivity for HMB45 and S100 confirming the diagnosis of melanoma [Figure 3]. Patient improved symptomatically after surgery and was referred for radiotherapy.
Figure 3: Histopathology sections showing features of a melanoma. (a) The tumor cells showing positivity for HMB-45 (×100). (b) Tumor cells showing cytoplasmic positivity for S100 (×100)

Click here to view

Melanocytes are of neural crest origin, and during development they migrate to the skin, uvea, mucous membranes, and leptomeninges. On rare occasions, few melanocytes that remain in the central nervous system (CNS) can become neoplastic.[4] Majority of melanocytic lesions in the brain are metastatic. According to Hayward's criteria, a solitary lesion in the leptomeninges, the pineal gland, or the intramedullary region is more likely to be a primary CNS melanoma, provided that there is no melanoma elsewhere in the body.[5] The World Health Organization (WHO) categorizes primary CNS melanocytic lesions into diffuse melanocytosis, melanocytoma, and malignant melanoma.[6] Diffuse leptomeningeal melanocytosis occurs in the setting of neurocutaneous melanosis syndrome and is characterized by leptomeningeal thickening or nodularity.[7] Meningeal melanocytoma is a benign low-grade tumor and the common locations are the cervical/thoracic spine, posterior fossa, Meckel's cave, and cerebellopontine angle. Primary malignant melanoma is a rare aggressive dural-based tumor commonly occurring in the cerebellopontine angle, pineal gland, cerebrum, and spine.[8]

Clinically, the patients with CNS melanoma can present with features of raised intracranial tension, cranial nerve palsies, neurological deficits, seizures, or subarachnoid hemorrhage.[7] On computed tomography (CT), melanomatous lesions appear hyperdense and show a homogenous contrast enhancement.[6],[7],[8],[9],[10] On MR imaging, these lesions show an increased signal on T1- and decreased signal on T2-weighted images due to the presence of melanin. On perfusion imaging, these lesions show hyperperfusion.[6] The MRS findings described in extracranial melanomas are elevated choline, lactate, and amino acids such as taurine, alanine, lysine, and glutamate.[10] The differential diagnoses are other pigmented tumors such as pigmented schwannoma and meningioma.

On macroscopy, melanocytomas and melanomas appear as reddish brown-to-black masses. On sections stained with hematoxylin and eosin, melanocytomas show sheets of well-differentiated epitheloid melanocytes having round-to-oval nuclei with finely dispersed chromatin, occasional single eosinophilic nucleoli, and moderate amount of cytoplasm with abundant granular melanin pigment.[9] On immunohistochemisty, the tumor cells show diffuse strong HMB45 and S-100 immunopositivity. Surgical excision is the treatment of choice for primary melanoma. Postoperative radiotherapy and chemotherapy help in prolonging remission.[8],[9],[10] In conclusion, primary malignant melanomas of CNS are extremely rare tumors and show pathognomonic imaging features such as increased perfusion, and amino acid peaks representing taurine, lysine, and glutamine on MRS.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

 » References Top

Farrokh D, Fransen P, Faverly D. MR findings of a primary intramedullary malignant melanoma: Case report and literature review. Am J Neuroradiol 2001;22:1864-6.  Back to cited text no. 1
Poe LB, Roitberg D, Galyon DD. Neurocutaneous melanosis presenting as an intradural mass of the cervical canal: Magnetic resonance features and the presence of melanin as a clue to diagnosis: Case report. Neurosurgery 1994;35:741-3.  Back to cited text no. 2
Faro SH, Koenigsberg RA, Turtz AR, Croul SE. Melanocytoma of the cavernous sinus: CT and MR findings. AJNR Am J Neuroradiol1996;17:1087-90.  Back to cited text no. 3
Somers KE, Almast J, Biemiller RA, Silberstein HJ, Johnson MD, Mohile NA. Diagnosis of primary CNS melanoma with neuroimaging. Am Soc Clin Oncol 2013;31:9-11.  Back to cited text no. 4
Hayward RD. Malignant melanoma and the central nervous system. A guide for classification based on the clinical findings. J Neurol Neurosurg Psychiatry 1976;39:526-30.  Back to cited text no. 5
Balakrishnan R, Porag R, Asif DS, Satter AM, Taufiq M, Gaddam SS. Primary intracranial melanoma with early leptomeningeal spread: A case report and treatment options available. Case Rep Oncol Med 2015;2015:293802.  Back to cited text no. 6
Vanzieleghem BD, Lemmerling MM, Van Coster RN. Neurocutaneous melanosis presenting with intracranial amelanotic melanoma. Am J Neuroradiol 1999;20:457-60.  Back to cited text no. 7
Jaiswal S, Vij M, Tungria A, Jaiswal AK, Srivastava AK, Behari S. Primary melanocytic tumors of the central nervous system: A neuroradiological and clinicopathology study of five cases and brief review of literature. Neurol India 2011;59:413-9.  Back to cited text no. 8
[PUBMED]  [Full text]  
Shinde SV, Shenoy AS, Savant HV, Balasubramaniam SB. Coexistent intracerebral metastatic melanoma and meningioma. Neurol India 2017;65:110-2.  Back to cited text no. 9
[PUBMED]  [Full text]  
Bourne RM, Stanwell P, Stretch JR, Scolyer RA, Thompson JF, Mountford CE, et al. In vivo and ex vivo proton MR spectroscopy of primary and secondary melanoma. Eur J Radiol 2005;53:506-13.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3]

This article has been cited by
1 Imaging and pathological diagnosis of primary intracranial malignant melanoma: A case report and literature review
Wei-Li Long, Fu-Yong Chen, Xiao-Lin Huang, Jun-Xu Lu, Yan-Neng Xu
Medicine. 2023; 102(5): e32767
[Pubmed] | [DOI]
2 Primary intracerebral melanoma: A case report
Aleksandra Paunovic, Igor Lazic, Filip Milisavljevic, Aleksandar Miljkovic, Žarko Nedeljkovic, Ivan Bogdanovic, Marija Rakonjac, Rosanda Ilic
Medicinski glasnik Specijalne bolnice za bolesti štitaste žlezde i bolesti metabolizma. 2021; 26(83): 53
[Pubmed] | [DOI]
3 Amelanotic Meningeal Melanoma with Leptomeningeal Dissemination: A Case Report and Systematic Literature Review
Simin Zhang, Weina Wang, Xiaorui Su, Qiaoyue Tan, Huaiqiang Sun, Zefan Liu, Ni Chen, Qiyong Gong, Qiang Yue
World Neurosurgery. 2019; 122: 229
[Pubmed] | [DOI]


Print this article  Email this article
Online since 20th March '04
Published by Wolters Kluwer - Medknow