Reactive lymphoid hyperplasia of the liver characterized by an angiofollicular pattern mimicking Castleman's disease

Reactive Lymphoid Hyperplasia of the Liver Incidentally Found in a 55-Year-Old Woman with a History of Ulcerative Colitis

Reactive lymphoid hyperplasia (RLH) is a benign disease, rarely occurring in the liver. Reactive immune phenomenon has been reported in association with its occurrence, but the true pathogenesis is unknown. No case was reported in association with inflammatory bowel disease. We report a case of RLH of the liver in a patient with ulcerative colitis (UC). A 55-year-old woman with UC went to the outpatient clinic with abdominal pain, and antibiotics were prescribed with diagnosis of acute appendicitis. Imaging study detected a mass in the liver but ruled out appendicitis. She was referred to our hospital for further examination after pain improving. A 12 mm hypoechoic mass was detected in the liver on ultrasonography. There were no typical malignant findings on computed tomography and magnetic resonance imaging. Regular image follow-up was recommended, but the patient strongly requested surgery because of family history of malignant disease. Laparoscopic partial hepatectomy was performed. Histopathological findings revealed a conglomerate hyperplasia of lymphoid follicles with germinal centers. Infiltrating lymphocytes were non-neoplastic. Final diagnosis was RLH of the liver. UC is chronic inflammatory bowel disease and may be related to RLH, but there is no clear explanation at this point. This is the first known reported case of RLH of the liver in a patient with UC. But the relationship between the RLH and UC remains uncertain. Further investigation and case accumulation are necessary.

Clinical features, natural history and outcomes of pseudolymphoma of liver: A case-series and systematic review

BACKGROUND

Pseudolymphoma is a rare, benign, nonspecific condition that forms a mass-like lesion characterized by the proliferation of non-neoplastic lymphocytes. Lacking of specific clinical symptoms, serological markers, and imaging features, the diagnosis is difficult. We reporte five cases of hepatic pseudolymphoma and provide a systematic review of existing literatures to improve our understanding of this rare liver disease.

METHODS

We followed-up five cases of hepatic pseudolymphoma in West China Hospital from January 2002 to January 2022. We also summarized the cases of hepatic pseudolymphoma from January 1981 to December 2021 through the PubMed database and comprehensively analyzed the characteristics of the cases.

RESULTS

The pathologic features of the five cases were characterized by benign lymphoid tissue hyperplasia, lymphoid follicle formation, and a polarized germinal center. Immunohistochemistry, in situ hybridization, and gene rearrangement revealed non-malignant lymphoma. Besides, a total of 116 cases have been reported in the PubMed database from 1981 to 2021. The incidence of hepatic pseudolymphoma is higher in middle-aged and elderly women and has been reported more frequently in Asia. All cases were pathologically diagnosed, among which 85.95% of the patients were treated by surgery.

CONCLUSIONS

Hepatic pseudolymphoma is an extremely rare benign disease, mainly in middle-aged and elderly women. Without distinctive clinical and imaging characteristics, pathological diagnosis is the highly reliable method at present. Thus, in the absence of risk factors for a primary liver tumor or metastatic tumor in middle-aged and elderly women, the possibility of pseudolymphoma should be considered to avoid extensive treatments.

Liver pseudolymphoma (reactive lymphoid hyperplasia): Difficulty in radiological and pathological diagnosis

Pseudolymphoma of the liver (reactive lymphoid hyperplasia) (RLH) is a rare condition. It is usually asymptomatic and detected incidentally on radiological imaging. Imaging features are similar to hepatic adenoma, hepatocellular carcinoma, cholangiocarcinoma, and malignant lymphoma and are not specific for pseudolymphoma of the liver. Percutaneous core biopsy is insufficient to distinguish pseudolymphoma of the liver from low-grade malignant lymphoma and extranodal marginal lymphomas. In this article, we present a case of hepatic RLH of a patient who presented with a skin rash on the leg and was detected incidentally on radiological imaging.

A case of reactive lymphoid hyperplasia of the liver in a patient with autoimmune hepatitis

Background

Reactive lymphoid hyperplasia (RLH) of the liver is a benign disorder. It is usually observed in the skin, orbit, thyroid, lung, breast, or gastrointestinal tract, but rarely in the liver. Since the first report of RLH of the liver in 1981, only 75 cases have been described in the past literature. Herein, we report a case of RLH of the liver in a patient with autoimmune hepatitis (AIH), which was misdiagnosed as hepatocellular carcinoma (HCC) preoperatively and resected laparoscopically.

Case presentation

A 43-year-old Japanese woman with autoimmune hepatitis was followed up for 5 years. During her medical checkup, a hypoechoic nodule in segment 6 of the liver was detected. The nodule had been gradually increasing in size for 4 years. Abdominal ultrasound (US) revealed a round, hypoechoic nodule, 12 mm in diameter. Contrast-enhanced computed tomography (CT) demonstrated that the nodule was slightly enhanced in the arterial dominant phase, followed by perinodular enhancement in the portal and late phases. A magnetic resonance imaging (MRI) scan showed low signal intensity on the T1-weighted image (T1WI) and slightly high signal intensity on the T2-weighted image (T2WI). The findings of the Gd-EOB-DTPA-enhanced MRI were similar to those of contrast-enhanced CT. Tumor markers were all within the normal range. The preoperative diagnosis was HCC and a laparoscopic right posterior sectionectomy was performed. Pathological examination revealed that the nodular lesion was infiltrated by small lymphocytes and plasma cells, and germinal centers were present. Immunohistochemistry was positive for B cell and T cell markers, indicating polyclonality. The final diagnosis was RLH of the liver.

Conclusions

The pathogenesis of RLH of the liver remains unknown, and a definitive diagnosis based on imaging findings is extremely difficult. If a small, solitary nodule is found in female patients with AIH, the possibility of RLH of the liver should be considered.

Reactive lymphoid hyperplasia of the liver. A case report

Reactive lymphoid hyperplasia of the liver is an unusual benign lesion of unknown pathogenesis. The largest reported series to date includes only 7 cases. Reactive lymphoid hyperplasia can be radiologically confused with malignant tumors such as hepatocellular carcinoma or metastases. Histological differential diagnosis should be chiefly made with lymphomas, Castleman disease and primary biliary cirrhosis. We report the clinicopathological findings in a 54-year-old woman with an incidental hepatic lesion when she consulted for hematuria. After histological, immunohistochemical and molecular studies, the diagnosis of reactive lymphoid hyperplasia was made.

Reactive lymphoid hyperplasia of the liver: A case report

RATIONALE

Reactive lymphoid hyperplasia (RLH) of the liver is an uncommon benign lesion. It is usually difficult to differentiate from hepatocellular carcinoma (HCC), peripheral-type cholangiocellular carcinoma (CCC), combined HCC-CCC, and liver metastases. On account of its rarity and controversial issues, we report a case report and review the literature to discuss its clinical features, treatments, radiological, and immunohistochemical characteristics.

PATIENT CONCERNS

A 54-year-old woman had a history of primary biliary cirrhosis and chronic cholecystitis. She complained of finding a lesion in the right liver during her last medical check-up by abdominal B type ultrasound. The Contrast-enhanced computed tomography revealed a circular and low-density lesion in the right posterior lobe of the liver, approximately 22.0 × 18.7 mm in size. On magnetic resonance imaging, the lesion showed low-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Laboratory test results were almost normal.

DIAGNOSIS

After the postoperative pathological and immunohistochemical examination, the patient was finally diagnosed as having RLH.

INTERVENTIONS

The patient received right posterior lobe hepatectomy and cholecystectomy.

OUTCOMES

The patient was discharged 11 days after surgery. No evidence of recurrence was noted 1 year after the surgery.

LESSONS

Although RLH of the liver is rare, it is necessary to be considered in a liver lesion, especially in female patients. This case report may advance the understanding of RLH of the liver and reduce the number of mistakenly diagnosed patients.

Diagnosis and treatment of hepatic pseudolymphoma

Pseudolymphoma, also known as reactive lymphoid hyperplasia or nodular lymphoid lesion, can occur in the gastrointestinal tract, pancreas, eyelids, skin, etc.; however, pseudolymphoma of the liver rarely occurs. Because of the small number of individual case reports of hepatic pseudolymphoma in most institutions, there is a lack of information available regarding its pathogenesis, optimal treatment, and prognosis. Patients with hepatic pseudolymphoma often present non-specific clinical and imaging features, without specific tumor markers. The diagnosis of this disease mainly depends on postoperative pathological and immunohistochemical evaluations and genetic examination; timely and complete surgical resection is currently the most important treatment.

Intrahepatic Reactive Lymphoid Hyperplasia: A Case Report and Review of the Literature

Introduction

Reactive lymphoid hyperplasia (RLH) is a rare and benign lesion found in organs of the gastrointestinal tract, skin, lung, orbit, and more rarely in the liver. Due to its similar appearance on imaging, it is hard to differentiate from primary liver malignancies. The following is a case report of a patient presenting with a suspicious liver lesion found to be RLH associated with primary biliary cirrhosis (PBC), after surgical resection.

Presentation of Case

A 54-year-old woman presented with nonspecific abdominal pain, and her workup included axial imaging of the abdomen that showed a suspicious lesion in her liver. After an extensive workup, which included a percutaneous biopsy, failed to confirm a diagnosis, a laparoscopic surgical resection was recommended.

Discussion

RLH is a rare condition of the liver, presenting in a suspicious fashion and raising concerns for a primary liver malignancy. RLH should be considered in the differential diagnosis of small hepatic lesions in middle-age females in the absence of any significant risk factors for hepatocellular carcinoma (HCC). RLH tends to be associated with PBC of the liver.

Conclusion

RLH of the liver is a rare, hard to diagnose, benign lesion. When intrahepatic, it cannot be easily differentiated from primary liver tumors and frequently requires surgical resection for pathological diagnostic confirmation.

Pseudolymphoma of the liver: a case report and literature review

Pseudolymphoma is a benign lymphocytic tumor-like lesion, and its occurrence in the liver is rare. Here, we report the case of a 78-year-old woman with pseudolymphoma of the liver. She had a history of tremors for several years. Therefore, she underwent computed tomography (CT) for screening, and liver tumors were incidentally identified. She did not have any history of liver disease. Liver function test results and tumor marker levels were all within normal limits, and viral markers for hepatitis were negative. Contrast-enhanced CT revealed four nodules measuring up to 13 mm in diameter with ring enhancement in both lobes of the liver. On magnetic resonance imaging, the lesions showed slightly high intensity on T2-weighted images and high intensity on diffusion-weighted images. Because of atypical imaging findings, the tumors could not be definitively diagnosed. Therefore, we performed laparoscopic limited resection of segments 2, 3, 4, and 8 of the liver. The final pathological diagnosis was pseudolymphoma of the liver. The patient has had no signs of recurrence for 6 months after the surgery. Although pseudolymphoma of the liver is rare, it is necessary to consider it in the differential diagnosis of a liver tumor.

The Hyaline Vascular Type of Castleman’s Disease of the Ovary

Castleman’s disease in the pelvic cavity is rare. We present a 72-year-old woman with hyaline vascular type of Castleman’s disease of the right ovary. Right ovarian enlargement was detected in the medical examination. Computed tomography revealed a solid mass, measured 2.5 cm in size, in the right ovary. A bilateral salpingo-oophorectomy was performed. Morphologically, lymphoid follicles with regressed germinal centers (GCs) were surrounded by a broad mantle zone composed of concentric rings of small lymphocytes, and the hyalinized blood vessels with plump endothelial cells penetrated radially into GCs. Proliferation of follicular dendritic cells, which were positive for CD21 and epidermal growth factor receptor, were detected in GCs and mantle zone. No other lesions were found. To the best of our knowledge, this is the first case of hyaline vascular type of Castleman’s disease of ovarian primary.

Pseudolymphoma of the liver: Report of a case and review of the literature

We report a case of pseudolymphoma of the liver in a 49-year-old woman without an underlying disease except for liver hemangioma. A 20-mm nodule was incidentally found in segment 2 of the liver by abdominal ultrasonography during a regular follow-up of the hepatic hemangioma. After a series of radiological examinations, a left lateral sectionectomy was performed because malignant hepatic tumor could not be excluded. The patient was discharged uneventfully 7 days after the operation. The pathology examination revealed a pseudolymphoma. No recurrence of the tumor was found 5½ years after the operation. To the best of our knowledge, only 46 cases of pseudolymphoma of the liver have been reported to date. A review of the literature showed that pseudolymphomas occur predominantly in females (89.4%), usually occur as a single tumor (80.4%), are no more than 20 mm in size (90.6%), and are frequently associated with either autoimmune disease or chronic liver disease. Because an accurate diagnosis is difficult to establish, vigilant follow-up is indicated, and surgical intervention is the choice of treatment once the suspiciousness of malignancy has been raised.

Reactive lymphoid hyperplasia of the liver and pancreas. A report of two cases and a comprehensive review of the literature

BACKGROUND

Reactive lymphoid hyperplasia (RLH) is a rare non-neoplastic extranodal pathology with exceedingly rare occurrence in the liver and pancreas. We present two cases of hepatic RLH, one which had coinciding pancreatic involvement. To the best of our knowledge, concomitant hepatic and pancreatic RLH has not been previously reported. We also present a comprehensive review of the literature on hepatic and pancreatic RLH.

METHODS

An extensive literature search for all published reports on hepatic or pancreatic RLH was conducted. Data on clinical, radiographic and histopathological features were extracted in addition to therapeutic options and outcomes.

RESULTS

Forty-two hepatic and three pancreatic cases of RLH were described in the literature. The mean age of hepatic cases was 58 years, with a male-to-female ratio of above 1:7. Almost 25% of cases were associated with internal malignancy. Four hepatic cases were managed through active observation. The remainder (84%) underwent surgical resection. Due to their small number, no meaningful analysis could be made on the pancreatic cases. No recurrences were identified in any of the reported cases.

CONCLUSION

RLH should be considered in the diagnosis of hepatic nodules where biopsies fail to demonstrate malignant cells. Confirmed RLH lesions should be managed by active observation. Investigation and treatment of any potential source of lymphoid reactivity should be undertaken. More reports on pancreatic RLH need to be studied prior to drawing any useful recommendations on its management.

Reactive lymphoid hyperplasia of the liver: a clinicopathological study of 7 cases

Background. Reactive lymphoid hyperplasia (RLH) of the liver is a benign focal liver mass that may mimic a malignant liver tumor. Although rarely encountered in clinical practice, it often poses diagnostic and management dilemmas. Methods. Cases diagnosed as hepatic RLH between January 1996 and June 2011 were investigated in a retrospective study. Clinicopathological features as well as follow-up information of the cases were studied. Results. A total of seven cases of hepatic RLH were investigated, with a median age of 46 years (range: 33–76 years). Hepatic RLH was accompanied by concomitant diseases in some patients. The average size of hepatic lesions of our cases was 45 mm (range: 15–105 mm). All of the cases were not accurately diagnosed until confirmed by pathological findings, and surgical resections were performed for all. Postoperative course was uneventful for all of the patients during followup. Conclusions. RLH of the liver is a rare benign disease with a female predilection of unknown etiology. It is very difficult to correctly diagnose this disease without pathological results. Subtle differences on radiological findings of it may be helpful for differential diagnosis from other diseases. Curative resection of the lesion is suggested for the treatment of this disease.

Hepatic reactive lymphoid hyperplasia in a patient with primary biliary cirrhosis

Reactive lymphoid hyperplasia (RLH) of the liver is an extremely rare lesion characterized by the proliferation of non-neoplastic lymphocytes forming follicles. Hepatic RLH is known to be associated with gastrointestinal carcinoma and autoimmune diseases including primary biliary cirrhosis (PBC). We report a case of hepatic RLH in a patient with PBC and gastric cancer. A 68 year old Japanese woman with a 10 year history of liver enzyme abnormality was admitted. Laboratory testing revealed that her anti-mitochondrial antibody was markedly elevated. Five mo after the diagnosis of PBC, she was found to have gastric cancer. Abdominal computed tomography disclosed a liver nodule in S8, suggesting metastatic gastric carcinoma. Histopathologically, the resected liver lesion comprised of a nodular proliferation of small lymphocytes with lymphoid follicles. This is the first reported case of hepatic RLH in a patient with both PBC and gastric cancer. Pre-operative diagnosis of hepatic RLH by clinical imaging is extremely difficult. Therefore, a needle biopsy could be useful to make a diagnosis of hepatic RLH, especially to differentiate from metastatic gastrointestinal carcinoma.

Hepatic pseudolymphoma: a clinicopathological study of five cases and review of the literature

Hepatic pseudolymphoma is a rare and controversial condition, the clinicopathological characteristics of which have not been well documented. In this study, we retrospectively examined clinical and pathological features of five patients (two males and three females, 40-81 years old) with hepatic pseudolymphoma. Two patients had multiple lesions (two lesions each). Three patients had histories of chronic liver disorders, including primary biliary cirrhosis, nonalcoholic steatohepatitis, and chronic viral hepatitis B. Tumor sizes ranged from 0.5 to 5.5 cm in diameter (average, 2.1 cm). Histologically, hepatic pseudolymphoma consisted of tumorous infiltrates of mature lymphocytes with multiple lymph follicles or clusters of epithelioid histiocytes. Lymphocytes characteristically extended into nearby portal tracts. Ductal structures positive for cytokeratin 7 were entrapped in the peripheral parts of nodules. In situ hybridization of immunoglobulin light chains revealed B lymphocytes and plasma cells to be polyclonal. In addition, clonal rearrangements of immunoglobulin heavy chains could not be shown in any cases using PCR. Two patients were diagnosed by needle biopsy. Interestingly, their nodules spontaneously diminished in size without any treatment. Malignant transformation was not observed in any cases during the follow-up periods. In conclusion, this study revealed that hepatic pseudolymphoma had benign behavior. The diagnosis of hepatic pseudolymphoma can be challenging especially with biopsied specimens, but could be aided by a characteristic growth pattern, in situ hybridization, analyses of gene rearrangements, or a follow-up based on images.

Pseudolymphoma of the liver associated with primary biliary cirrhosis: a case report and review of literature

We report a case of two pseudolymphomas of the liver in a 63-year-old Japanese woman with primary biliary cirrhosis. One of the lesions was found incidentally during a medical examination, presenting as a 10 mm hypodense nodule that revealed hyperdensity in the early phase and hypodensity in the late phase in computed tomography (CT) after injection of contrast medium. Retrospectively, the 10 mm nodule had first been discovered as a 4 mm nodule during CT 4 years previously. Superparamagnetic iron oxide-enhanced MRI revealed another 4 mm hyperintense nodule in segment 6 in addition to the 10 mm hyperintense nodule in segment 7. CT during arterial portography revealed two hypointense nodules. Findings with other imaging modalities such as ultrasonography, magnetic resonance imaging, and hepatic angiography were consistent with hepatocellular carcinoma. A right posterior segmentectomy was performed, and the lesions were microscopically diagnosed as pseudolymphoma. To the best of our knowledge, only 31 other cases of this disease have ever been reported, with a highly asymmetrical male:female ratio of 1:9.7. Although we could find only one case of transformation of hepatic pseudolymphoma into lymphoma in the liver, the exact nature of development from benign pseudolymphoma to malignant lymphoma is still not fully understood and cases of hepatic lymphoma need to be followed carefully.

Castleman-like reaction due to toxic substance ingestion

Castleman disease (CD) is an uncommon lymphoproliferative disorder with a unique histopathology. Generally diagnosis is not difficult for an experienced pathologist. However, not usually, some histopathological entities or tissue reactions may mimic CD. Here CD-like reaction due to toxic substance ingestion has been presented.

Histiocyte-rich reactive lymphoid hyperplasia of the liver: unusual morphologic features

Reactive lymphoid hyperplasia (RLH) of the liver is a rare entity and has also been termed nodular lymphoid lesion or pseudolymphoma of the liver. We report a case of hepatic RLH exhibiting unusual histiocyte-rich histologic features in a 47-yr-old woman in conjunction with a renal cell carcinoma. A follow-up computed tomography scan was done 14 months after a right radical nephrectomy for renal cell carcinoma revealed a nodular lesion in segment 5 of the liver. The lesion was interpreted as metastatic renal cell carcinoma or hepatocellular carcinoma based on the history of the patient and radiologic findings. Wedge resection of segment 5 was done with sufficient distance from the mass. Microscopically, the lesion was composed predominantly of peculiar histiocytic proliferation and was characterized by lymphoid aggregates forming a lymphoid follicle with germinal centers. The present case and prior cases reported in the literature suggest that RLH of the liver appear to be a heterogenous group of reactive inflammatory lesions that are often associated with autoimmune disease or malignant tumors.

Reactive lymphoid hyperplasia of the liver: A case report and review of literature

A case of a 53-year-old female patient with reactive lymphoid hyperplasia (RLH), clinically designated as pseudolymphoma of the liver is described in this article. The patient was admitted to our hospital for further evaluation of hepatic tumors incidentally discovered at another hospital. Various diagnostic methods, including ultrasonography (US), computerized tomography (CT), magnetic resonance imaging (MRI) and hepatic angiography displayed three small lesions in the liver with outstanding findings consistent with hepatocellular carcinoma (HCC). Surgical resection was performed and the three lesions were microscopically diagnosed as RLH of the liver. The lesions comprised a massive infiltration of lymphoid cells with follicles and hyalinized inter-follicular spaces. Immunohistochemical examination revealed that infiltrating lymphocytes had no prominent nuclear atypia and polyclonality. RLH of the liver is a very rare condition and only twelve cases have been reported in the English literature. Majority of the reported cases were middle-aged women and about half of them had some immunologic abnormalities such as autoimmune thyroiditis, Sjogren's syndrome, primary immunodeficiency, primary biliary cirrhosis. Since they are often clinically misdiagnosed as HCC, surgery is the choice of treatment for these patients. Although their pathology resembles malignant lymphoma, the clinical course is completely benign. The authors propose that RLH of the liver can be discriminated from HCC by its clinical features.

[Nodular lymphoid hyperplasia of the liver. Pseudolymphoma]

We present a rare pathological entity of the liver and review the literature.

CASE REPORT

a 33-year-old asymptomatic woman showed a space-occupying lesion on liver segment VI, which was detected incidentally on ultrasound examination performed for a gynecological disorder. Computed tomography and magnetic resonance imaging of the liver confirmed a 3-cm lesion in segment VI. Segmentectomy of segment VI was performed. Pathological diagnosis was nodular lymphoid hyperplasia of the liver. Nodular lymphoid hyperplasia or pseudo-lymphoma is a highly uncommon disease that usually develops in cirrhotic liver. Our patient was free of liver disease.

Pseudolymphoma of the liver: Sonographic findings and review of the literature

We report a case of hepatic pseudolymphoma in a 67-year-old woman that was detected during an abdominal sonography screening. The lesion was further evaluated using CT, MRI, angiography, and contrast-enhanced sonography. The imaging features of this tumor are discussed herein. The diagnosis of pseudolymphoma was achieved via sonographically guided biopsy. The lesion regressed completely within 1 year.

Segmentectomy for reactive lymphoid hyperplasia of the liver: Report of a case

We report a case of reactive lymphoid hyperplasia (RLH) of the liver in a 72-year-old woman without any symptoms. To our knowledge, only 11 other cases of this disease have ever been reported. The lesion was found incidentally during a medical examination, as a hypoechoic mass in segment 3 of the liver on ultrasonography. The findings of computed tomography, magnetic resonance imaging, and angiography suggested a malignancy. Frozen section diagnosis of an intraoperative needle biopsy suggested malignant lymphoma, so we performed lateral segmentectomy of the liver. Macroscopically, the tumor was well defined, white, and firm. Microscopically, there was polymorphous lymphoplasmacytic infiltration, with various-sized and -shaped lymphoid follicles. Lymphocytic infiltration was also observed in the portal tracts around the nodular lesion. Immunohistochemical study revealed polyclonality, confirming a pathological diagnosis of RLH of the liver. We discuss the clinicopathologic characteristics of this unusual disease.

Reactive lymphoid hyperplasia of the liver in a patient with multiple carcinomas: a case report and brief review

A rare case of reactive lymphoid hyperplasia (RLH) of the liver in a 75-year-old woman admitted to hospital for surgical treatment of gastric, caecal and colon carcinomas is described here. Two nodular lesions in the left and right lobes of the liver were clinically diagnosed as metastatic tumours by computed tomography of the abdomen. A demarcating grey-white mass of size 1.4 cm was observed in a partially resected liver specimen. On examining the lesion microscopically, it was found to be composed of hyperplastic lymphoid follicles, lymphocytes, plasma cells, other inflammatory cells and interlaced hyalinised fibrous tissues. In the portal tracts around the lesion, chronic inflammatory cell infiltrates were seen, but no interface hepatitis or lymphoid follicle was observed. No evidence of monoclonality was observed by immunohistochemistry for B and T cell markers, in situ hybridisation for kappa and lambda light chains, and polymerase chain reaction analysis of immunoglobulin heavy chains or T cell receptor beta and gamma gene rearrangements. Bcl-2 immunoreactivity was not observed in the germinal centre. Epstein-Barr virus (EBV) antigen (latent membrane protein-1) and EBV-encoded small RNAs were not detected. A proliferation neither of myofibroblasts nor of cells positive for follicular dendritic cell markers was observed. RLH, formerly known as pseudolymphoma, has been reported of the liver in only 14 cases and is considered to be a differential diagnosis of small nodular lesions of the liver. That RLH has an inflammatory reactive nature, not a neoplastic disposition, and that EBV does not participate in the pathogenesis of RLH is supported by this case.

Nodular lymphoid lesion of the liver with simultaneous focal nodular hyperplasia and hemangioma: discrimination from primary hepatic MALT-type non-Hodgkin's lymphoma

Nodular lymphoid lesion (NLL) of the liver is a rare but unique entity and has also been termed reactive lymphoid hyperplasia of the liver. We describe the histological, immunohistochemical and molecular biologic findings of a case with NLL and two other tumors of the liver. The nodular lymphoid mass found in the liver was composed of heterogeneous small lymphocytes forming reactive follicles. Plasma cells, few immunoblasts, centroblasts, few macrophages, epithelioid cells, and giant cells were seen. The lymphoid infiltrate displaced the adjacent hepatic parenchyma. By immunohistochemistry and molecular studies, the lymphocytes were found to be polyclonal. The diagnosis of NLL was made. In addition to NLL, focal nodular hyperplasia and hemangioma were detected. The discrimination of NLL from primary hepatic malignant non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue-type may pose diagnostic difficulties and may require the use of immunohistochemical and molecular techniques. The simultaneous occurrence of NLL with focal nodular hyperplasia and hemangioma in the liver has not been described before.