CASE 10319 Published on 01.07.2013

Primary hepatic follicular lymphoma

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Oliveira C1, Condesso D1, Barbosa L1, Catarino R1, Estevão A1, Caseiro-Alves, F1

1- Imaging Department, University Hospital and Faculty of Medicine, Coimbra/PT; Email:kat.catarina@gmail.com
Patient

67 years, female

Categories
Area of Interest Liver ; Imaging Technique Ultrasound, CT, MR-Diffusion/Perfusion, MR
Clinical History
A 67-years-old female was referred for further investigation, after the detection of a focal liver lesion in a routine abdominal ultrasound. No symptoms or clinical findings at the physical exam were described. There was no history of weight loss, fever or other abnormalities. Tumor markers were negative.
Imaging Findings
Ultrasound revealed a hypoechoic nodular lesion with 3cm in left hepatic lobe(Fig1). The patient underwent a multiphase abdominal CECT. The nodule was isodense in all phases except for mild hipodensity seen at the portal phase(Fig.2). At MRI it had low signal intensity(SI) on T1-WI and high SI on T2-WI. On T2-fat saturated images two additional smaller nodules were depicted in the right lobe, displaying similar imaging features(Fig.3). After gadoxetic acid administration, only the largest lesion could be recognized, showing minimal enhancement in the arterial phase, and isointensity on portal and delayed phase without contrast uptake in the hepatobiliary phase(Fig.4). On DWI using a high b value (800 s/mm2), tumor restriction was depicted in all the lesions and in several subcentimeter nodules(Fig.5). US-guided biopsy of the dominant nodule was performed. Immunohistochemistry was consistent with non-Hodgkin's follicular lymphoma. The patient underwent a cervical, thoracic and pelvic CT which was normal. Bone marrow biopsy was also negative.
Discussion
Primary hepatic lymphoma(PHL) is a rare condition, defined as a lymphoma limited to the liver[1]. It usually occurs in immunodeficient patients or associated with chronic hepatitis C infection[2]. The majority of the PHL originates in B-cells, being most frequently of the diffuse large cell type[2]. Clinical symptoms are unspecific, mostly represented by upper abdominal pain and/or hepatomegaly. A solitary, dominant liver mass is more common than a multiple nodular presentation. On US, lesions usually appear hypoechoic, but can be almost anechoic, simulating a cyst. On CT, lesions are isoattenuating or occasionally hypoattenuating on plain scans and hypoattenuating on the portal venous phase. On delayed scans, contrast retention within the tumor interstitial space may cause relative hyperattenuation.
The differential diagnosis with metastases can usually be sought, since the liver nodules tend to be more homogeneous and lacking the typical rim enhancement pattern. PHL appearing as a solitary, hypovascular, heterogeneous mass is however more difficult to characterize. If multiple nodules are encountered, other differentials should be included, such as fungal micro-abscesses especially if dealing with the immunosuppressed patient[3]. Reactive lymphoid hyperplasia can also be included in the range of differentials, meanwhile it tends to display a more hypervascular feature on the arterial phase[4].
PHL displays MR features analogous to other primary liver tumors, with mild/moderately high in SI on T2-WI and moderately to low SI on T1-WI. Typically, the lesion is hypovascular and hypointense in the hepatobiliary phase since it is devoid of hepatocytes. DWI appear today as an excellent tool to detect small liver lesions attending to its high contrast capability and absence of intravascular signal. ADC values seem to be non-discriminant concerning the lymphoma subtype[5]. In our case, DWI revealed more lesions than any other sequence in isolation, including the hepatobiliary phase after gadoxetic acid administration. We believe that this is related to the technical conditions of our post-contrast GRE T1-WI sequence that used a lower acquisition matrix and a larger slice thickness. We must stress however that no histological confirmation was obtained from the smaller lesions assumed to represent lymphoma foci on the basis of their SI characteristics and restriction on DWI. Due to the completely different management of PHL patients treated with chemotherapy, with or without concomitant radiotherapy, tissue biopsy is the rule in order to achieve the proper diagnosis. The prognosis is variable, and, in general, a good response to aggressive chemotherapy schemes can be observed.
Differential Diagnosis List
Primary hepatic follicular lymphoma.
Secondary lymphoma
Metastatic disease
Fungal abcesses
Reactive lymphoid hyperplasia
Final Diagnosis
Primary hepatic follicular lymphoma.
Case information
URL: https://www.eurorad.org/case/10319
DOI: 10.1594/EURORAD/CASE.10319
ISSN: 1563-4086