Lymphoma of the liver: Clinicopathological features of 19 patients.

BACKGROUND: Liver is an organ that could either be involved by widespread lymphoma or rarely as a primary site of lymphoma. Although secondary involvement of liver by lymphoma is relatively common, primary hepatic lymphoma (PHL) represents only about 0.016% of all cases of non-Hodgkin lymphoma. Understanding the clinicopathological features of hepatic lymphoma would direct appropriate treatment and patient management. METHODS: We did a retrospective cohort study of 19 patients with liver biopsy-proven lymphoma, either as part of a systemic lymphoma or as a primary lesion, who were evaluated and treated at Harbor-UCLA Medical Center between 2004 and 2014. RESULTS: The 19 cases were divided into two groups. Nine of them showing systemic involvement including not only liver but also spleen and/or lymph nodes were grouped together. The other 10 cases which showed confined liver lesions without involvement of other lymphoid structures were grouped in the PHL group. Clinical features of the two groups were compared. Our study demonstrated that PHL most commonly affected middle-aged individuals (median age: 50 years), with a male-to-female ratio of about 2.3 to 1. The most frequent presenting symptom was right upper quadrant pain. In contrast, the group with systemic lymphoma involving liver most commonly affected younger patients (median age: 40 years), with a male-to-female ratio of about 8 to 1, and with abdominal pain as well as fever/chills as the most common presenting symptoms. The tumor burden at the presentation as suggested by serum lactate dehydrogenase (LDH) level was statistically significantly lower in the PHL group compared to the systemic group in this study (p<0.05). Viral infections were found in both groups, and we did not observe a clear association of any particular viral infection with PHL. Diffuse large B-cell lymphoma was identified as the major type of primary hepatic lymphoma (8 of 10 cases). Finally, the prognosis in the PHL group demonstrated by the duration of follow-up (average follow up: 50 months) was statistically significantly better than that in the systemic group (average follow up: 5.5 months), p<0.01. CONCLUSION: Patients with PHL showed different clinicopathological features from those with widespread lymphoma involving liver. The outcome of the patients with PHL appeared much more favorable than that of the patients with liver involvement by systemic lymphoma in this study.