Related Experiment Video

Updated: Aug 20, 2026

Ex Vivo Culture of Circulating Tumor Cells in the Cerebral Spinal Fluid from Melanoma Patients to Study Melanoma-Associated Leptomeningeal Disease
06:25

Ex Vivo Culture of Circulating Tumor Cells in the Cerebral Spinal Fluid from Melanoma Patients to Study Melanoma-Associated Leptomeningeal Disease

Published on: March 29, 2024

Primary diffuse leptomeningeal melanomatosis presenting as chronic meningitis and dense spinal plaques

Lauren Baldwin1,2, Hadleigh Cuthbert3, Satheesh Ramalingham4

  • 1Stoke Mandeville Hospital, Aylesbury, UK l.baldwin5@nhs.net.

Practical Neurology
|August 18, 2026
PubMed

Insights

Primary diffuse leptomeningeal melanomatosis (PDLM) is a rare CNS tumor often misdiagnosed. Repeated "dry taps" during lumbar punctures may indicate extensive infiltration, aiding diagnosis.

Area of Science:

  • Neuro-oncology
  • Central Nervous System Tumors

Background:

  • Primary diffuse leptomeningeal melanomatosis (PDLM) is an exceptionally rare and aggressive central nervous system (CNS) melanocytic tumor.
  • PDLM frequently mimics inflammatory or infectious leptomeningeal diseases, leading to diagnostic challenges.

Purpose of the Study:

  • To highlight the diagnostic difficulties and characteristic features of PDLM.
  • To emphasize the importance of considering PDLM in refractory leptomeningeal disease.

Main Methods:

  • Case presentation of a woman in her early 60s with hydrocephalus and diffuse leptomeningeal enhancement.
  • Initial misdiagnosis as neurosarcoidosis, followed by progression despite immunosuppression and "dry taps" during lumbar punctures.
  • Identification of a melanocytic neoplasm with a GNA11 mutation via intradural biopsy.

Main Results:

  • The patient initially presented with symptoms mimicking neurosarcoidosis.
  • Repeated lumbar punctures failed to yield cerebrospinal fluid (CSF), a potential indicator of extensive leptomeningeal infiltration.
  • Intradural biopsy confirmed a melanocytic neoplasm with a GNA11 mutation, diagnosing PDLM.

Conclusions:

  • PDLM is often misdiagnosed due to its rarity and presentation.
  • Repeated failure to obtain CSF during lumbar puncture can be a crucial diagnostic clue for PDLM.
  • Early recognition of characteristic imaging features and prompt biopsy are essential for timely PDLM diagnosis and management.
Keywords:
NEURORADIOLOGYNEUROSURGERYPATHOLOGYSURGERYTUMOURS

More Related Videos

Comprehensive Autopsy Program for Individuals with Multiple Sclerosis09:41

Comprehensive Autopsy Program for Individuals with Multiple Sclerosis

Published on: July 19, 2019

Related Concept Videos

Cryptococcal Meningitis01:27

Cryptococcal Meningitis

Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,...
Bacterial Meningitis I: Introduction01:22

Bacterial Meningitis I: Introduction

Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...
Multiple Sclerosis l: Introduction01:19

Multiple Sclerosis l: Introduction

Multiple sclerosis is a chronic autoimmune disease of the central nervous system (CNS) that affects the brain, spinal cord, and optic nerves. It is an inflammatory demyelinating disorder and a leading cause of neurological disability in young adults.EpidemiologyMS commonly begins between 20 and 40 years of age and is twice as common in women. Its exact cause remains unclear, but genetic susceptibility contributes, with higher risk in first-degree relatives and identical twins. A greater...
Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
Bacterial Meningitis01:24

Bacterial Meningitis

Bacterial meningitis is a severe infectious disease involving inflammation of the meninges, the protective membranes surrounding the brain and spinal cord. It occurs when pathogenic bacteria cross the blood–brain barrier and enter the cerebrospinal fluid. Common causative organisms include Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b, Listeria monocytogenes, and Escherichia coli K1. The exact route of entry varies by pathogen and host condition.Routes of Entry...
Brain Abscess l: Introduction01:26

Brain Abscess l: Introduction

A brain abscess is a focal, intracerebral infection characterized by a localized collection of pus within the brain parenchyma, resulting from microbial invasion and the body’s inflammatory response. It progresses through stages: early and late cerebritis, followed by early and late capsule formation, reflecting tissue destruction, immune response, and eventual encapsulation.Etiology and PathogenesisCausative organisms vary with source and host factors, often involving polymicrobial infections,...