Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver

Primary hepatic diffuse large B-cell lymphoma presenting unusual imaging features

Primary hepatic lymphomas are frequently misdiagnosed, due to their rarity and non-specific clinical manifestations. As these tumors can be successfully treated with chemotherapy and/or radiotherapy, early recognition on imaging is essential to avoid unnecessary surgery. We report a case of primary hepatic lymphoma in a 73-year-old woman presenting with a 1-week history of persistent fever and elevated hepatobiliary enzymes. Ultrasound showed a hypoechoic hepatic mass in the anterior segment. Dynamic contrast-enhanced computed tomography (CT) revealed an ill-defined solitary mass showing peripherally dominant slight-to-moderate enhancement contrasting with a hypovascular central area. On magnetic resonance imaging, the mass showed moderate hyperintensity on T2-weighted imaging, hypointensity on T1-weighted imaging, doughnut-like hyperintensity on diffusion-weighted imaging, and an obviously low apparent diffusion coefficient (ADC). The pattern of enhancement resembled that of CT. Neither calcification nor any fat component was observed. Doughnut-like accumulation was seen on ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/CT without other FDG-avid lesions. Imaging findings suggested the possibility of cholangiocellular carcinoma, but the low ADC and extremely high FDG accumulation were suggestive of malignant lymphoma, and diffuse large B-cell lymphoma was pathologically confirmed from percutaneous biopsy. The mass disappeared after radiochemotherapy, and no recurrence has been observed for 3 years.

Hepatic Manifestations of Lymphoproliferative Disorders

Hepatic abnormalities in patients with lymphoproliferative disorders are common and can occur from direct infiltration by abnormal cells, bile duct obstruction, paraneoplastic syndrome, hemophagocytic syndrome, drug-induced liver injury, opportunistic infections, and reactivation of viral hepatitis. Hepatic involvement by lymphoma is often in association with systemic disease and rarely seen as a primary hepatic lymphoma. Vanishing bile duct syndrome is a well-known complication of Hodgkin disease. Antiviral prophylaxis for hepatitis B virus (HBV) reactivation is recommended for all HBsAg⁺ patients undergoing chemotherapy and all resolved HBV patients undergoing rituximab therapy and stem cell transplantation.

Primary hepatic lymphoma: dilemmas in diagnostic approach and therapeutic management

Primary hepatic lymphoma (PHL) is a very rare malignancy and is characterized by liver involvement at presentation with no affectation of the spleen, lymph nodes, peripheral blood, bone marrow, or other tissues until at least 6 months after diagnosis. PHL should be considered in the differential diagnosis in a patient with space-occupying liver lesions and normal levels of alpha-fetoprotein and CEA. A computed tomography (CT) scan is the commonly used modality for staging lymphomas. The widespread use of positron emission tomography/CT results in the improvement in the accuracy of detecting the extent of disease, response evaluation, and prognostication. The liver biopsy, due to its pleomorphic appearances in the needle biopsy specimen, can be very challenging. Current literature favors the combination of chemotherapy as the frontline treatment for its least invasiveness and improved survival. Favorable prognosis of PHL can be obtained by early surgery combined with chemotherapy in strictly selected patients. However, the optimal therapy is still unclear and the outcomes are uncertain.

Imaging of cellular proliferation in liver metastasis by [18F]fluorothymidine positron emission tomography: effect of therapy

Although [(18)F]fluorothymidine positron emission tomography (FLT-PET) permits estimation of tumor thymidine kinase-1 expression, and thus, cell proliferation, high physiological uptake of tracer in liver tissue can limit its utility. We evaluated FLT-PET combined with a temporal-intensity information-based voxel-clustering approach termed kinetic spatial filtering (FLT-PET(KSF)) for detecting drug response in liver metastases. FLT-PET and computed tomography data were collected from patients with confirmed breast or colorectal liver metastases before, and two weeks after the first cycle of chemotherapy. Changes in tumor FLT-PET and FLT-PET(KSF) variables were determined. Visual distinction between tumor and normal liver was seen in FLT-PET(KSF) images. Of the 33 metastases from 20 patients studied, 26 were visible after kinetic filtering. The net irreversible retention of the tracer (Ki; from unfiltered data) in the tumor, correlated strongly with tracer uptake when the imaging variable was an unfiltered average or maximal standardized uptake value, 60 min post-injection (SUV(60,av): r = 0.9, SUV(60,max): r = 0.7; p < 0.0001 for both) and occurrence of high intensity voxels derived from FLT-PET(KSF) (r = 0.7, p < 0.0001). Overall, a significant reduction in the imaging variables was seen in responders compared to non-responders; however, the two week time point selected for imaging was too early to allow prediction of long term clinical benefit from chemotherapy. FLT-PET and FLT-PET(KSF) detected changes in proliferation in liver metastases.