Abdominal Ultrasound Findings of Tumor-Forming Hepatic Malignant Lymphoma.

Aim/background: Evaluations of abdominal ultrasonography (US) findings of primary and secondary tumor-forming hepatic malignant lymphoma (HML) have not been adequately reported. In this study, we elucidated US and contrast-enhanced US (CEUS) findings in patients with HML.

Materials/methods: From January 2006 to March 2017, 25 patients with HML were enrolled (primary 7, secondary 18), each of whom was diagnosed pathologically. They were divided into 2 groups based on tumor diameter (cutoff, 30 mm). US imaging findings were retrospectively analyzed.

Results: All tumors in patients with a small HML (<30 mm in diameter, small group, n = 14) were revealed as homogeneous hypo-echoic type (100%), with penetrating sign observed in only 1 patient. Tumors in 11 patients in the small group, examined with CEUS, showed homogeneous enhancement in the early vascular phase (91%) and a washout pattern in the portal phase (100%), and they were revealed as defective in the post-vascular phase (100%). In the large group (≥30 mm; n = 11), tumors were revealed as a heterogeneous hypo-echoic lesion in 10 (91%) and penetrating sign was observed in 8 (73%). Dilatation of the distal intrahepatic bile duct by the tumor was observed in 4 patients in the large group. In 7 large group patients examined with CEUS, imaging findings in the early vascular phase varied, with 5 (71%) showing a washout pattern in the portal phase and 5 (71%) revealed as defective in the post-vascular phase.

Conclusion: We found that US imaging features of HML differ depending on the tumor diameter.