Case ReportPrimary Diffuse Leptomeningeal Melanomatosis: Case Report and Review of the Literature
Introduction
Primary melanocytic neoplasms originate from the native melanocytes of the leptomeninges.1 When benign neoplastic transformation of these melanocytes occurs, these lesions are known as melanocytomas.2, 3 When malignant, they known as leptomeningeal melanomatoses.2, 3 Clinical manifestations are nonspecific and can mimic a myriad of autoimmune, infectious, and neoplastic causes, complicating diagnosis. We report a rare case of a patient with primary diffuse leptomeningeal melanomatosis (PDLM) without evidence of a primary focus. In addition, we performed a comprehensive review of the literature. Thirty-two cases of PDLM, in addition to the current case, have been previously described in the literature.
Section snippets
Case Description
A 44-year-old white woman with no significant past medical history presented to the emergency department of an outside hospital with confusion, left facial droop, slurred speech, hemiplegia, and hemiparesthesia. A stroke alert was initiated and she was treated with tissue plasminogen activator, although subsequent magnetic resonance imaging (MRI) was negative for stroke. The patient was discharged with a diagnosis of complex migraine headache. Three months later, she was referred to our
Discussion
Melanocytes are embryologically of neural crest origin, and during development, migrate to the leptomeninges, and in particular, the ventral medulla.4 Rarely, leptomeningeal melanocytes may undergo malignant transformation, which is termed leptomeningeal melanomatosis.1 The transformation may diffusely affect the meninges of the entire neuroaxis. The incidence of PDLM is unknown, but extremely uncommon. PDLM may be associated with neurocutaneous syndromes such as neurocutaneous melanosis
Conclusions
PDLM is an extremely rare disease with vague presenting symptoms, radiologic findings, and laboratory results. Diagnosis is therefore elusive, and PET/CT may be a useful diagnostic adjunct. Neurosurgical intervention is limited to CSF diversion for hydrocephalus and biopsy to obtain diagnosis. If PDLM is suspected and initial biopsy is nondiagnostic, a PET scan may localize an additional hypermetabolic site that may be appropriate for a second biopsy with potentially higher yield.
References (35)
- et al.
[Melanocytoma and meningeal melanocytosis, similar but different lesions]
Cir Cir
(2017) - et al.
Primary melanocytic neoplasms of the central nervous system
J Clin Neurosci
(2010) - et al.
Leptomeningeal carcinomatosis as primary manifestation of pancreatic cancer
J Clin Neurosci
(2016) - et al.
Primary malignant melanoma of meninges: atypical presentation of subacute meningitis
Pediatr Neurol
(1995) - et al.
[Primitive leptomeningeal malignant melanoma: a rare etiology of pachymeningitis and leptomeningitis]
Rev Neurol (Paris)
(2010) - et al.
Primary diffuse leptomeningeal melanomatosis: description and recommendations
J Clin Neurosci
(2018) - et al.
Malignant transformation of intracranial meningeal melanocytoma. Case report and review of the literature
Neuropathology
(2011) - et al.
Meningeal melanocytoma of the middle cranial fossa (the Meckel's cave)
Neurol India
(2015) - et al.
Primary Amelanotic leptomeningeal melanomatosis in a child: a rare but severe disease
World Neurosurg
(2016) - et al.
Neurocutaneous melanosis
Childs Nerv Syst
(2004)
Primary diffuse meningeal melanomatosis: radiologic-pathologic correlation
AJNR Am J Neuroradiol
MR of neurocutaneous melanosis
AJNR Am J Neuroradiol
Primary intracranial leptomeningeal melanomatosis
J Korean Neurosurg Soc
Primary diffuse meningeal melanomatosis
Neurologist
Primary malignant meningeal melanomatosis: a clinical, radiological and pathologic case study
Acta Neurol Belg
Brain 18F-choline PET/CT in primary diffuse leptomeningeal melanomatosis
Acta Neurol Belg
F-18 fluorodeoxyglucose PET/CT and post hoc PET/MRI in a case of primary meningeal melanomatosis
Korean J Radiol
Cited by (12)
Primary Diffuse Leptomeningeal Melanomatosis in an Indian Child With Review of Literature
2024, Pediatric NeurologyDiagnostic challenges of primary diffuse leptomeningeal melanomatosis in early adolescence: A case report
2022, Brain and DevelopmentCitation Excerpt :Due to the paramagnetic effects of melanin, the typical imaging appearance of primary diffuse leptomeningeal melanomatosis is iso- to hyperintense on T1-weighted images, hypointense on T2-weighted images, and intensely enhanced on gadolinium contrast images [1,4,12,13]. However, signal intensity differs if lesions are amelanotic, which manifests as hypo- to isointense on T1 and iso- to hyperintense on T2 [4,12,13]. Signal patterns also vary depending on melanin content [2,14].
Diffuse leptomeningeal enhancement in a patient with rapidly progressive dementia: Answer
2019, Journal of Clinical NeurosciencePrimary diffuse leptomeningeal melanomatosis: a challenging diagnosis
2023, Neurological Sciences
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.