Figure 2a.

Radiologic features of undifferentiated pleomorphic sarcoma in two patients. (a, b) Undifferentiated pleomorphic sarcoma in a 57-year-old man with left leg swelling: Axial (a) and coronal (b) contrast-enhanced CT images show mostly homogeneous enhancement of a well-circumscribed soft-tissue mass (straight arrow) invading the left anterolateral abdominal wall and obliterating the left external iliac vein. A reactive lymph node (curved arrow on b) is depicted in the left inguinal region. (c–e) Undifferentiated pleomorphic sarcoma in a 64-year-old man with vague right upper quadrant pain. (c) Axial contrast-enhanced CT image shows areas of low attenuation reflecting necrosis (*) within a sharply marginated, heterogeneously enhancing mass (arrow). (d, e) Axial half-Fourier acquisition single-shot turbo spin-echo (HASTE; Siemens, Erlangen, Germany) (d) and equilibrium phase contrast-enhanced T1-weighted fat-suppressed (e) MR images of the same patient as in c better show infiltration into the adjacent liver (arrow), as well as areas of necrosis (*).