Color Doppler ultrasound in ovarian fibrosarcoma. 
Primary ovarian fibrosarcoma is a very rare tumor.  Its Doppler waveform characteristics have not been described before.  A 35-year-old woman presented with a 5-cm solid ovarian mass.  Intratumoral artery resistance index (RI) and pulsatility index (PI) were very low (0.19 and 0.21, respectively).  Peak systolic velocity calculated by using transvaginal Doppler ultrasound was higher than expected (24.8 cm/s).  Postoperatively, the histopathologic diagnosis was primary ovarian fibrosarcoma, stage Ia. Low vascular resistance can be encountered in ovarian fibrosarcomas.  In young patients presenting with a solid adnexal mass, intratumoral Doppler waveform investigations might offer some help for earlier prediction of rare malignant tumors like fibrosarcomas.