Linear and whorled nevoid hypermelanosis with bilateral giant cerebral aneurysms

A 24-year-old woman presented with bilateral giant intracavernous carotid artery aneurysms manifesting as a cavernous sinus syndrome on the left side, and anisocoria, ophthalmic pain, and oculomotor paresis on the left side. Physical examination showed mild hyperextensibility of the metacarpophalangeal joints, amelogenesis imperfecta, and hyperpigmentation following Blaschko lines. Analysis of the NEMO gene for incontinentia pigmenti syndrome and of collagen III for Ehlers-Danlos type IV was normal. Skewed X-inactivation patterns in blood lymphocytes were detected. To the best of our knowledge, this association of linear hyperpigmentation and cerebral aneurysms has never been previously reported.