An 80-year-old woman was admitted to our hospital with right hypochondralgia. Abdominal ultrasonography showed a well-circumscribed round lesion in segments 5 and 6 of the liver. Contrast-enhanced ultrasonography (CEUS) indicated that the tumor was enhanced in the arterial phase, changing to hypo-enhanced 30 seconds following contrast injection. After admission, the patient complained of epigastralgia, and CEUS subsequently demonstrated extravasation from the tumor. Although abdominal angiography was successful for achieving hemostasis, the tumor grew rapidly and the patient died. An autopsy revealed the presence of sarcomatoid hepatocellular carcinoma (HCC). The literature is lacking in details regarding CEUS findings for sarcomatoid HCC and rupture. We herein report a rare case of sarcomatoid HCC.