To analyze the CT and MRI features of primary hepatic sarcomatoid carcinoma.

A retrospective study was conducted on 16 patients with primary hepatic sarcomatoid carcinoma who presented to Wenzhou People's Hospital of Zhejiang Province and the Second Affiliated Hospital of Wenzhou Medical University from January 2009 to June 2019. There were 8 males and 8 females, with age ranging from 35 to 71 years (average 56.8 years). The site, size, shape, margin, density of signal, adjacent tissue changes and degree enhancement of tumor were analyzed.

Tumors in the liver in the 16 patients were all solitary, with 11 in the right and 5 in the left liver. The maximum diameter of tumor ranged from 3 to 16cm (average 8.5cm). On plain CT scanning (n=16), the tumors were round or oval in 6, and lobulated or irregular in 10 patients. The margins of the tumors were clear in 10 and unclear in 6 patients. All tumors showed low density, with 15 tumors showing uneven density, with necrosis and liquefaction of different sizes in the center, while 1 tumor showing uniform density. On plain MRI scanning (n=4), four tumors had clear margins, with necrosis and liquefaction seen in the center of the tumors. The solid part showed a slightly lower signal on T₁ weighted imaging and a slightly higher signal on T₂ weighted imaging. The liquefaction focus of central necrosis showed higher signal intensity on T₂ weighted imaging. Enhanced scanning (n=12 on CT enhancement and n=4 on MRI enhancement), the margins of the tumors were enhanced in the arterial phase. The enhancement was continued into the portal venous and delayed phases in 7 patients. Strip septate and margin enhancement in the tumor were enhanced in the arterial phase. The enhancement was continued into the portal venous and delayed phases in 7 patients. Inhomogeneous strengthening in the tumor was enhanced in the arterial phase. The enhancement was continued into the portal venous and delayed phases in 1 patient. Inhomogeneous strengthening in the tumor was enhanced in the arterial phase. The enhancement was continued into the portal venous phase. In the delayed phase, enhancement in the tumor decreased, but there was continuous enhancement of the margin and interval of the tumor in 1 patient.

Hepatic sarcomatoid carcinoma showed dual imaging characteristics of sarcoma and cancer. The imaging features of hepatic sarcomatoid carcinoma depended on the proportion of sarcomatoid components. Large intrahepatic tumors showed necrotic cystic degeneration, moderate or significant persistent enhancement in striped septum and margin of tumor.

Liver neoplasms; Sarcomatoid carcinoma; Tomography, X-ray computers; Magnetic resonance imaging