Persistent Intracranial Hypertension and Severe Hypoglycorrhachia in an Adult With Giant Congenital Melanocytic Naevi.

A 29-year-old female, with giant congenital melanocytic naevi (GCMN) presented with a-year history of symptoms and signs of intracranial hypertension. Investigations revealed raised cerebrospinal fluid (CSF) pressure and severe hypoglycorrhachia (low CSF glucose) without pleocytosis. Initial contrast-enhanced brain MRI was normal, but a repeat MRI after a year showed meningeal enhancement with mild communicating hydrocephalus. The raised intracranial pressure was treated with a lumbar-peritoneal shunt. Intraoperative CSF cytology revealed an abundance of squamous epithelia and degenerative cells, but no malignant cells. Her symptoms recovered with CSF diversion via shunt placement, but the hypoglycorrhachia remained. This case highlights the rare occurrence of a non-inflammatory cause of both intracranial hypertension and severe hypoglycorrhachia in a GCMN adult patient, with progressive radiological changes over time, consistent with a diagnosis of neurocutaneous melanosis.