Azygos anterior cerebral artery associated with hypoplastic A1 fragment of right anterior cerebral artery

Anterior cerebral arteries are paired and supply the major portion of the medial surface of the brain. They are branches of the intracranial part of the internal carotid artery and form the anterior portion of the circle of Willis (CW) which is situated in the interpeduncular fossa. During routine dissection in the department of anatomy, All India Institute of Medical Sciences, Bibinagar, Hyderabad, a rare variation had been observed in the CW, azygos anterior cerebral artery associated with hypoplastic A1 fragment of the right anterior cerebral artery in a 63-year-old female cadaver. It is important to identify and study this kind of rare variation for surgeons, anatomists, and radiologists during dissection, surgical, radiological, and diagnostic interventions.