Malignant perivascular melanoma mimicking primary central nervous system vasculitis

Abstract

Primary central nervous system vasculitis (PCNSV) is an idiopathic disorder resulting in multifocal inflammation of small arteries and veins of the cortex and leptomeninges. Typically there is no evidence of vasculitis outside the central nervous system [7]. It is a rare disorder, but, nevertheless, responsible for 3–5 % of cerebrovascular accidents in patients aged \50 years [5]. The pathogenesis is poorly understood and the underlying cause is still unknown [2]. Diagnostic criteria include (1) acquired neurological deficits remaining unexplained after complete evaluation; (2) cerebral angiography with alternating segments of stenosis with normal or dilated intervening segments, and arterial occlusions; (3) no evidence of systemic vasculitis or any other condition that could mimic the angiographic findings [4]. The clinical signs and symptoms are nonspecific (e.g., nausea, headache, focal-neurological deficits, neuropsychological disturbances), reflecting the diffuse and often patchy nature of the pathologic process contributing to a high number of misleading diagnoses [7]. While magnetic resonance imaging of the brain is abnormal in more than 90 % of patients, the findings are unspecific. Multiple small or large ischemic lesions with partial hemorrhagic transformation are frequently found. Cerebrospinal fluid (CSF) analysis is usually abnormal with a modest elevation of total protein and lymphocytes. Cerebral angiography may show abnormal vessels, but has a low sensitivity and specificity [2]. Brain biopsy remains the gold standard for the diagnosis of PCNSV. After exclusion of other causes of multifocal infarctions or pleocytosis in CSF (e.g., endocarditis) brain biopsy is mandatory to confirm vasculitis before initiating a potentially toxic therapy [1]. Here we are presenting a patient with a diffuse perivascular melanoma, mimicking PCNSV. We report on a 45-year-old male who suffered from a dull holocephalic headache for three months, loss of weight (more than 10 kg over the last six months), intermittent nausea and vomiting, and progressive exhaustion during the last weeks. He also reported transient paresthesia in the right arm, gait disturbances, and blurred vision. The patient denied any fever and night sweats. His past medical history showed a naevus excised 15 years ago, which was later identified as a malignant melanoma. Frequent follow-up examinations were unremarkable. His temperature was 37.2 C; other vital signs, the general examination and routine blood studies including the erythrosedimentation rate (ESR) and acute phase M. Schneider (&) P. P. Urban Abteilung fur Neurologie, Asklepios Klinik Barmbek, Rubenkamp 220, 22291 Hamburg, Germany e-mail: mart.schneider@asklepios.com