Lauren Chorny1, Dominique Montecino2, Ansley Madala3, Maya Murzello3, Zoë Waugh4, Ian Dryden5, Arman Seyedsaadat6, Rabih Tawk7, Vivek Gupta6, Benjamin Eidelman1
1Mayo Clinic Jacksonville, Neurology Dept, 2Neurology, Mayo Clinic Jacksonville, Neurology Dept, 3Mayo Clinic Jacksonville- Neurology Dept, 4Mayo Clinic Jacksonville, 5Mayo Clinic Jacksonville, Pathology Dept, 6Mayo Clinic Jacksonville, Diagnostic Radiology Dept, 7Mayo Clinic Jacksonville, Neurosurgery Dept
Objective:
Primary leptomeningeal melanocytosis is a rare neoplasm derived from the melanocytes in the leptomeninges with a broad clinical presentation. We report a case of a previously healthy 37-year-old woman with persistent headaches found to have primary leptomeningeal melanocytosis.
Background:
A 37-year-old woman presented with a five-month history of headaches, weight loss, and episodic numbness affecting the right side of her face, arm, and leg, lasting approximately ten minutes and occurring multiple times daily. These symptoms progressed to difficulty performing activities of daily living. She was initially evaluated one month after symptom onset and treated symptomatically for complex migraines. Over time, she developed diplopia, prompting an ophthalmology consultation, which revealed bilateral papilledema, thus raising concerns for idiopathic intracranial hypertension (IIH). A lumbar puncture showed an opening pressure of 25 mmHg with pleocytosis and elevated protein. Acetazolamide was initiated with temporary symptom relief. Brain MRI with and without contrast revealed diffuse leptomeningeal enhancement, leading to a provisional diagnosis of neurosarcoidosis, for which she was prescribed prednisone. Differential diagnoses at the time included infectious, inflammatory, and neoplastic etiologies. Due to worsening symptoms, she was transferred for increased level of care. A subsequent brain MRI without contrast showed diffuse leptomeningeal T1-hyperintensities with restricted diffusion, raising suspicion for leptomeningeal melanocytosis. Extensive workup for primary malignancy was unremarkable. Cytology from cerebrospinal fluid (CSF) analysis identified atypical epithelioid cells, suspicious for primary melanocytic neoplasm. Brain biopsy revealed atypical melanocytic neoplasm of the meninges.
Conclusions:
This case underscores the diagnostic challenges of primary leptomeningeal melanocytosis, despite early MRI findings of diffuse leptomeningeal T1-hyperintensities. The detection of melanocytic neoplasm in CSF, combined with MRI findings, suggest that future diagnostic approaches could benefit from the use of genetic markers of cells without necessitating invasive procedures such as brain biopsy.
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