Large congenital arteriovenous malformations (AVM) may result in heart failure and death. We are reporting such combination with the AVM localized to the right thoracobrachial region. Remarkable postmortem findings included right renal and adrenal hemihyperplasia; the right adrenal fetal cortex presenting cytomegaly, endocrine pancreas hyperplasia, and heterotopic adrenal cortex with cytomegaly in the left lateral ventricle choroids plexus. The combination appears to be unique. The only previously reported example of adrenal cortex in the choroid plexus presented several features strongly suggestive of Beckwith-Wiedemann syndrome. Therefore, we postulate that additional uncommon findings in Beckwith-Wiedemann syndrome may include arteriovenous malformations and heterotopic adrenal tissue in choroids plexus.