Pleomorphic hyalinizing angiectatic tumor of soft parts: conventional and functional MRI features.

Pleomorphic hyalinizing angiectatic tumor is a neoplasm of uncertain behavior, with a high rate of local tumor recurrence, but no reports of metastases. It generally occurs in the subcutaneous tissue of the lower limbs. On magnetic resonance imaging (MRI), pleomorphic hyalinizing angiectatic tumor usually presents as a soft tissue mass, with well or ill-defined margins, with hypointense signal on T1- and hyperintense signal on T2-weighted imaging. Internal fat signal may be seen and necrotic-cystic degeneration can also be present, with contrast enhancement in its solid portions. However, there is a lack of description of the characteristics of this tumor on functional MRI sequences. In this article, we report a case of pleomorphic hyalinizing angiectatic tumor in the right ankle, with emphasis on MRI features, including conventional sequences and diffusion-weighted imaging, perfusion-weighted imaging, 4D time-resolved MR-angiography, and susceptibility-weighted imaging.