Primary hepatic lymphomas (PHLs) are exceedingly rare. Many reported cases are associated with various viral serologies, and some viruses may be implicated in lymphomagenesis through emerging, though as-of-yet uncertain, mechanisms. A review of the literature reveals previously reported cases of PHL, some of which support the potential roles of the hepatitis B and C viruses (HBV and HCV) in the development of PHL. We describe an exceptional case of primary hepatic high-grade B-cell lymphoma, discovered at autopsy, in a patient whose clinical history is significant for coinfection with both HBV and HCV. Additionally, attempts at cytogenetic testing of formalin-fixed, paraffin-embedded (FFPE) autopsy tissues, which we performed approximately ten years after the original autopsy, led us to question the utility of older tissue blocks in molecular and some immunohistochemical assays.
Primary hepatic lymphomas are unusual entities: primary hepatic non-Hodgkin lymphomas (NHLs) comprise 0.4% of all primary extranodal lymphomas and 0.016% of all NHLs [
We performed a search and systematic review of all autopsy reports in the electronic database at Saint Louis University Hospital between 1996 and 2016 for the term “lymphoma”. The inventory of discovered cases was then categorized based on the number and type of organs affected by the lymphoma, concomitant neoplastic processes, association with distinct infections, and unique and potentially intriguing cases. One case of primary hepatic lymphoma was identified in a 55-year-old man with a known history of HBV and HCV infections as well as cirrhosis; he had not previously been treated with antiviral therapies. No prior laboratory testing results were identified in our hospital system. The patient presented suddenly to the emergency department with mental status changes attributed to hepatic encephalopathy. Endoscopy revealed grade II esophageal varices and a flat-based ulcer near the gastroesophageal junction. The patient eventually developed multiorgan failure with coagulopathy and passed away. Death was due to liver failure in the setting of cirrhosis.
At the 2007 autopsy, the 2150-gram liver was extensively nodular, including areas of central necrotic parenchyma surrounded by a hemorrhagic rim. A focal area of gray-white parenchyma with an infiltrative appearance obscuring the cirrhotic nodules was determined to be probable Burkitt lymphoma by histomorphologic and limited immunohistochemical evaluation per the attending pathologists and according to the WHO classification at that time. Due to the infiltrative nature of the lesion, accurate gross dimensions proved difficult to measure. Microscopically, the cells in these areas were arranged in large nodules and were intermediate in size and mitotically active. The nodules were associated with necrosis and numerous apoptotic bodies. Extensive assessment revealed no other organs or lymphoid tissues to be involved by lymphoma, including the brain. Notably, sections of the left ventricle showed patchy subendocardial coagulative necrosis with a few polymorphonuclear cells, indicating an acute infarct one to several days old.
Almost ten years after the original autopsy, we ordered additional recut sections of the FFPE liver tissue blocks for potential cytogenetic testing. The following stains were performed on recut sections: hematoxylin and eosin (H&E), CD5, CD20, CD10, BCL-6, BCL-2, Ki-67 (MIB-1), Gömöri trichrome, and Epstein–Barr virus in situ hybridization (EBV-ISH). In preparation for fluorescence in situ hybridization (FISH), 4-micron-thick sections were cut, floated on a purified (
Recut H&E- and Gömöri trichrome-stained sections of liver showed the same nodules of autolyzed and necrotic hepatic parenchyma with intervening fibrous bands that were described in the original report (Figure
Broad fibrous bands separate nodules of necrotic hepatic parenchyma in the setting of cirrhosis (a) and diffuse infiltration of hepatic parenchyma by lymphoma cells admixed with nonneoplastic lymphocytes (b) (H&E); CD10 (c), CD20 (d), and BCL-6 (e) immunostains are strongly and diffusely positive in lymphoma cells; Ki-67 (f) shows a high proliferative index of nearly 100% in malignant cells, which are admixed with nonneoplastic lymphocytes.
Our results from this case describe a primary hepatic high-grade B-cell lymphoma associated with a remarkable combination of HBV and HCV infection, which has been reported only one other time in the literature [
Interestingly, both HBV and HCV are capable of disrupting multiple molecular pathways and the normal cellular microenvironment in the liver [
The role of HBV in the development of PHL is not well understood, although there is surfacing evidence regarding the association of HBV with DLBCL. Meta-analysis of observational studies has shown that HBV, like HCV, is associated with a two- to threefold risk of NHL [
Still more curious is the discussion of whether
Molecular testing is frequently limited in archival FFPE tissue, particularly with respect to analysis of ribonucleic acid (RNA). RNA degrades in cells prior to fixation in formalin, moreso during the postmortem interval prior to autopsy than during the so-called “cold ischemic” time in surgical specimens [
Given the 10-year age of the archival FFPE tissue blocks in our case, FISH was attempted using a dual-labeled break-apart probe directed onto
In situ hybridization for Epstein–Barr virus on liver sections was evaluated as negative in our case. However, this result should be interpreted with caution. Depending on the staining technique employed, the sensitivity for detection of viral RNA in archival FFPE tissue may be significantly lower than when the same procedure is performed on nonarchival tissue.
The above-described limitations raise a serious issue in the follow-up of patients. Although our described case was that of an autopsy specimen, it is critically important to be able to perform further analyses on archival tissue from surgically resected specimens, even after they may be years-old. For example, newer therapies for breast cancer, such as Her2 monoclonal antibodies, may be appropriate for a late metastasis; the ability to test archival tissue would theoretically save a patient from an invasive, costly, painful, and potentially morbid biopsy procedure (such as a biopsy or resection of a brain metastasis requiring craniotomy). The case we describe also brings to light another issue, that of the reclassification of certain tumors as discovery of molecular markers help refine diagnoses. The ability to test archival tissues for the newer molecular markers is critical to accurately diagnose and treat patients, to move forward, and to perform retrospective research. For these reasons, alternative methods of tissue preservation need be explored, such as tissue banking, which requires resources to snap-freeze and store frozen tissues at -70 C. The balance of optimal tissue preservation and cost is a delicate one. Currently, in the United States, tissue banking frozen tissues is not required by the accrediting agency (College of American Pathology/CLIA) standards. However, as molecular diagnoses are continually and increasingly becoming standard of practice, particularly in the realm of hematopoietic disease, better preservation of archived tissues will be necessary.
In summary, the patient’s autopsy confirmed the clinical diagnosis of end-stage cirrhosis and acute myocardial infarction. The contribution of the patient’s liver-restricted lymphoma to his clinical course and death is unclear. Aside from its rarity, the discovery of this lymphoma at autopsy is not unduly surprising: due to its diffuse, infiltrative nature and the nonspecific symptoms with which an afflicted patient may present, radiologic and clinical diagnosis of this condition proves challenging. Immunohistochemistry and the histomorphologic appearance of the malignant cells were essential to the diagnosis of high-grade B-cell lymphoma.
In general, RNA extraction from ten-year-old FFPE autopsy tissue blocks is limited and may require multiple techniques. Molecular testing using probes directed at specific RNA sequences is also challenging and failed in this case, despite conventional and double-treated procedural attempts. Alternatives to FFPE tissue preservation, such as tissue banking at -70 C, may be the preferred method for optimizing the ability to perform future molecular testing.
Current literature suggests a potential causative role of HBV and HCV in lymphomagenesis, albeit through a variety of mechanisms. The potential roles of either virus alone, dual coinfection status, and the tissue microenvironment (
The autopsy case we report in this manuscript was presented as an abstract in poster format at the United States and Canadian Academy of Pathology (USCAP) 106th Annual Meeting in San Antonio, Texas, USA.
The authors declare that there are no conflicts of interest regarding the publication of this article.
Our research was funded by a generous grant from the Department of Pathology at the Saint Louis University School of Medicine in Saint Louis, Missouri, USA.