LAUSR

BACKGROUND Pure fusiform aneurysms of the anterior communicating artery are rare. We describe a unique case of a patient with an anterior communicating artery fusiform aneurysm in the setting of several unusual cranial neurocristopathies, including a hypoplastic internal carotid artery, persistent craniopharyngeal canal, transphenoidal encephalocele, and ectopic, duplicated pituitary gland. We also review the literature on cranial base neurocristopathies and anterior communicating artery fusiform aneurysms. CASE DESCRIPTION The 46-year-old patient had a history of short stature, osteoporosis, obesity, cleft lip, decreased libido, congenital left eye blindness, headaches, and chronic nasal congestion. Magnetic resonance imaging revealed a 25 x 25 x 33 mm heterogenous soft tissue mass with ectopic pituitary gland extending transphenoidally and a duplicated pituitary stalk. Hormone panel revealed undetectable IGF-1 and GH, central hypogonadism, and elevated prolactin. Prior to presentation, an initial CTA had revealed a congenitally hypoplastic right internal carotid artery and 4.7 mm x 10.7 mm fusiform aneurysm of the anterior communicating artery. Digital subtraction angiogram confirmed stable morphology after nine years. Nonoperative management of aneurysm and cephalocele was elected with repeat CTA in one year. CONCLUSION We provide evidence that inherent arterial wall defects can contribute to fusiform aneurysm formation in the anterior communicating artery. We propose that small anterior communicating artery fusiform aneurysms without sclerotic or symptomatic features can be safely observed by describing the longest reported conservative management for this type of aneurysm. A high degree of suspicion for cerebrovascular anomalies should be maintained in patients who present with cranial neurocristopathies.