Intramuscular thrombosed arteriovenous hemangioma of the upper right arm mimicking a neuroma of the ulnar nerve: case report.

Objective And Importance: Soft tissue arteriovenous hemangiomas (AHs) are benign vascular hamartomas characterized by the presence of arteriovenous shunts. Few cases of soft tissue AHs have been found in the literature, and these were frequently described as cutaneous lesions of the limb or of the scalp. Intramuscular AHs are extremely rare. AHs are prevalent in children and women and are often associated with other types of malformations or genetic disorders. We present the case of an elderly woman with an intramuscular thrombosed AH on the volar side of the upper right arm. Owing to the close proximity of the ulnar nerve, this lesion was initially identified as a neuroma.

Clinical Presentation: A 70-year-old woman presented with a short history (a few months) of progressive growth of a nonpulsating, solid, palpable mass deeply localized in the distal third of the right upper arm. At the neurological examination, local evoked pain was the only sign detected. A Doppler ultrasound examination depicted a hyperechoic spherical lesion with widespread calcium deposits and necrosis.

Intervention: The exploration of the upper arm revealed a capsulated nodular lesion, 7 cm in diameter, that morphologically corresponded to a thrombosed vascular lesion. This lesion was removed en bloc, and an unequivocal connection with a muscular branch of the ulnar artery was detected. The histological analysis revealed AH.

Conclusion: Intramuscular AHs are rare and may easily be misdiagnosed as neuromas, especially when they are contiguous to a peripheral nerve.