Imaging of primary non-Hodgkin's lymphoma of the liver

AIM: To describe the radiological findings in primary liver lymphoma, which is a rare entity, presenting usually as a localized liver mass. MATERIALS AND METHODS: We reviewed retrospectively the imaging findings at presentation, of patients in whom a diagnosis of primary liver lymphoma was finally made histologically, The study period covered a 10-year period bet ween January 1990 and December 1999, There were seven patients, all men, wi th a mean age of 49.6 years. Each patient presented with hepatobiliary dise ase without peripheral adenopathy, Imaging prior to diagnosis included ultr asonography (seven patients), computed tomography (seven patients) and magn etic resonance imaging (MRI) (two patients). Appearances during and after a ggressive chemotherapy were reviewed. RESULTS: Imaging appearances were of either single or multiple Liver lesion s simulating Liver metastases, On ultrasound all foci of primary hepatic ly mphoma (PHL) were hypoechoic relative to normal liver. Computed tomography (CT) showed hypoattenuating lesions in all cases, and two cases showed rim enhancement following contrast administration. The MRI appearances were var iable, and no pathognomonic feature of PHL was identified, so that histolog y was required in all patients to establish the diagnosis. CONCLUSIONS: This paper demonstrates the spectrum of findings encountered o n various imaging modalities in PHL, We conclude that although PHL is a rar e condition, it should always be considered in the differential diagnosis o f liver metastases when no primary tumour is apparent. (C) 2001 The Royal C ollege of Radiologists.