Summary:
Hand aneurysms in infants are extremely rare and, unlike their adult counterparts, cannot be explained by repetitive trauma to the palm. When they occur, they are most often located in the ulnar artery. Usually there is no history of trauma, and an alternative diagnosis like malignancy must be excluded. Helpful physical findings to aid diagnosis include rapid appearance of a mass over the course of a few days, pulsatile nature, and location along the ulnar side of the hand. These cases can be challenging and excisional biopsy may be required if the lesion is thrombosed and does not have a characteristic appearance on imaging. Aneurysms located in the palmar arch or common digital arteries are usually treated with simple excision, while those located in the ulnar artery often require repair or reconstruction. Here we present a unique case of an infant with a pseudoaneurysm involving the superficial palmar arch on the radial side of the hand with a likely congenital etiology. Diagnostic challenges and treatment options are discussed.