A case of hepatic lymphoma showing a mixed pattern on contrast-enhanced ultrasonography

Abstract

Hepatic lymphomas generally appear as diffuse hypoechoic lesions. Here we report an unusual case of a hepatic lymphoma that showed a mixed pattern on contrast-enhanced ultrasonography (CEUS) because of central necrosis or hemorrhage. A woman in her 70s was referred to Hokkaido University Hospital with epigastralgia. Hepatic metastasis from gastroesophageal cancer was initially suspected on the basis of computed tomography (CT) findings. Ultrasonography (US) revealed a 91-mm, solid lesion with a clearly defined border in hepatic segment 4. The peripheral and central zones of the lesion were hypoechoic and hyperechoic, respectively. The arterial phase of CEUS revealed strong homogeneous enhancement in the peripheral zone and no enhancement in the central zone, while the portal phase showed a decrease in the peripheral zone enhancement. The nodule showed an enhancement defect in the postvascular phase. Contrast-enhanced CT also revealed homogeneous hyperenhancement in the peripheral zone and hypoenhancement in the central zone, which was considered to be a result of degeneration or hemorrhage. Both CEUS and CT showed multiple enlarged lymph nodes in the hepatic hilum. CT also showed multiple lymph node metastases in the neck. All these findings suggested that the mass was a secondary lesion. Biopsy confirmed a diagnosis of stage IV diffuse large B-cell lymphoma. The patient was treated with rituximab, cyclophosphamide, pirarubicin, vincristine, and prednisolone and achieved unconfirmed complete remission after 6 cycles of treatment.