Angioleiomyoma: magnetic resonance imaging features in ten cases.

Abstract

Angioleiomyoma is a rare, benign smooth muscle tumour arising from the tunica media of small veins and arteries and can occur anywhere in the body. The histological appearances are well documented, but there are relatively few descriptions of the magnetic resonance imaging (MRI) findings. A retrospective study of the clinical presentation, MRI appearances and histological findings of ten angioleiomyomas presenting as extremity soft tissue masses. MRI typically demonstrated a well-defined, oval mass located superficial to the fascia with the commonest sites being the hand (three cases) and ankle/foot (five cases). The lesion was isointense to muscle on T1-weighted spin echo images with heterogeneous increased internal T2W/short tau inversion recovery (STIR) signal intensity, which commonly appeared as multiple linear or branching areas of hyperintensity. Enhancement after IV gadolinium ranged from diffuse to heterogeneous. In a single case, central fat signal intensity was seen, while a further case showed marked T2W/STIR hypointensity due to diffuse hyalinisation within the lesion. This is the largest reported MRI series of extremity musculoskeletal angioleiomyoma. Angioleiomyoma should be considered in the differential diagnosis of a superficial mass in the hand or foot, particularly when characteristic linear or branching hyperintensity is seen on T2W or STIR images.