Association of Magnetic Resonance Imaging Features with Angioleiomyoma Histologic Subtype.

Background: Angioleiomyomas typically present as small, painful, soft-tissue tumors less than 2 cm in diameter. The features of angioleiomyomas on magnetic resonance (MR) imaging are not well understood, and the association of MR findings with histologic subtype is unclear. In the present study, the MR features of angioleiomyomas of average size were compared in relation to histologic subtype.

Methods: This retrospective review of medical records analyzed MR imaging data and histologic specimens from 18 consecutive patients with angioleiomyomas that were resected at our hospital during the period from January 2006 through December 2013.

Results: On T1-weighted images, lesions exhibited homogeneous areas that were isointense with skeletal muscle. However, T2-weighted images of solid and venous angioleiomyomas showed heterogeneous areas that were isointense or slightly hyperintense, while cavernous angioleiomyomas exhibited hyperintensity. Most lesions had a hypointense rim, and two thirds had adjacent vessels.

Conclusions: Our results suggest that MR findings for angioleiomyoma vary in relation to histologic subtype. T2-weighted images of solid and venous angioleiomyomas yielded specific MR findings that allowed for differentiation from other soft-tissue tumors, such as soft-tissue sarcomas. Most of these tumors exhibited isointense to slightly hyperintense regions, as compared with skeletal muscle, while findings for cavernous angioleiomyomas were nonspecific. Thus, clinical findings and MR imaging were almost sufficient for preoperative diagnosis of solid and venous angioleiomyomas.