Pseudolymphoma (reactive lymphoid hyperplasia) of the liver: A clinical challenge

Reactive lymphoid hyperplasia of the liver: A case report featuring characteristic nodular and perinodular enhancement

A 53-year-old female with primary biliary cholangitis was referred for the evaluation of a hepatic nodule identified during routine imaging. Ultrasonography revealed a homogeneous, hypoechoic, 18 mm nodule in segment 3 of the liver. On dynamic CT and MRI, the nodule showed mild enhancement at the hepatic artery-dominant phase. On diffusion-weighted images, the nodule exhibited pronounced hyperintensity with accompanying wedge-shaped perinodular hyperintensity (comet and comet-tail appearance). The nodule showed a portal perfusion defect on CT during arterial portography, and mild enhancement on CT during hepatic arteriography (CTHA). A nodular and wedge-shaped perinodular enhancement (comet and comet-tail appearance) in the CTHA was also clearly observed. The nodule demonstrated abnormal FDG uptake on 18F-FDG-PET/CT. An excisional biopsy was performed for histopathological diagnosis, and the nodule was diagnosed as reactive lymphoid hyperplasia (RLH). Diagnosing hepatic RLH by imaging is challenging due to its imaging findings overlapping with those of various malignant tumors, especially the nodular type of lymphomas, making differentiation particularly difficult. However, radiologists should note the perinodular early enhancement and the perinodular hyperintensity on diffusion weighted images, which are thought to be key imaging findings of RLH, along with other characteristics such as a single, small, homogeneous nodule with mild early enhancement and marked restricted diffusion. We propose to name the nodular lesion with perinodular early enhancement/hyperintensity on diffusion weighted images as 'comet and comet-tail appearances'.

A case of hepatic reactive lymphoid hyperplasia: the review of 23 cases from the literatures

A 70-year-old woman was referred to our hospital because of slight elevation of soluble interleukin-2 receptor (sIL-2R) and accumulation of 18F-fluorodeoxyglucose (FDG) in S8 of the liver on positron emission tomography. The mass was strongly suspected to be malignant because of contrast enhancement and enlargement in size of the mass, and suspicion of portal vein invasion. Hepatic S8 subsegmentectomy was performed for diagnostic and therapeutic purposes. Hematoxylin and eosin staining of the resected specimen showed small lymphocytes with no atypia and no formation of lymphoid follicles. Immunostaining showed CD3-positive cells in the interfollicular region and CD20-positive cells in the lymphoid follicles. Both CD10 and BCL-2 were negative in the follicular germinal center. CD138-positive plasma cells were observed and there was no light chain restriction. Based on polyclonal growth pattern of lymphocytes in the lymphoid follicles and interfollicular region, she was diagnosed with hepatic reactive lymphoid hyperplasia (RLH).Review of the English literature of hepatic RLH which referred to imaging findings yielded 23 cases, including this case. As a result, we suggest that liver biopsy should be performed for definitive diagnosis, when hepatic RLH is suspected by imaging findings and backgrounds.

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.

Benign focal liver lesions masquerading as primary liver cancers on MRI

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver malignancies. HCC and ICC have characteristic imaging findings, but a number of benign entities can appear similar and can cause diagnostic dilemma. Ideally, accurate and timely diagnosis of these conditions can help the patient to avoid a needle biopsy or even unnecessary treatment. In this article, we present various benign liver lesions that display imaging characteristics that are similar to HCC and ICC on magnetic resonance imaging (MRI) and discuss salient features that may assist in accurate diagnosis.

Diffusion-weighted imaging might be useful for reactive lymphoid hyperplasia diagnosis of the liver: A case report

BACKGROUND

Reactive lymphoid hyperplasia (RLH) of the liver is a rare liver lesion. It is considered difficult to differentiate radiologically from hepatocellular carcinoma, metastatic liver tumor and other pathologies.

CASE SUMMARY

A 54-year-old woman presented to our hospital with RLH of the liver. The patient had a diagnosis of metastatic carcinoma of the liver from an unknown origin and subsequently underwent partial hepatectomy. However, histopathological analysis revealed RLH. The lesion showed perinodular enhancement in the arterial phase on contrast-enhanced computed tomography and magnetic resonance imaging. On diffusion-weighted imaging (DWI), we encountered linear hyperintensity along the portal tract consecutive to the liver lesion, which is a new characteristic radiologic finding. This finding corresponded to the lymphoid cell infiltration of the portal tract. Furthermore, there was strongly restricted diffusion on the apparent diffusion coefficient map. We used these characteristic radiologic findings to diagnose the lesion as a lymphoproliferative disease.

CONCLUSION

The linear hyperintensity consecutive to the liver lesion on DWI provided additional valuable diagnostic information.

Primary hepatic extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), is one of the specific type of low-grade B-cell lymphoma not infrequently found worldwide. It typically involves mucosal sites such as stomach and conjunctiva; however, primary hepatic MALT lymphoma has been extremely rarely reported. We describe a case of hepatic MALT lymphoma in a 70-year-old male patient who underwent left hepatectomy due to the incidentally detected liver masses at a medical checkup. The resected specimen revealed multinodular masses consisting of small-to-intermediate-sized lymphoid cells with serpentine pattern and focal lymphoepithelial lesions. The tumor cells were diffusely positive for CD20 and Bcl-2 but negative for CD3, CD10, CD5, CD23, CD43, and cyclinD1. The Ki-67 labeling index was 10% and immunoglobulin heavy chain gene rearrangement study confirmed monoclonal proliferation. In this paper, we discuss several unique clinicopathologic characteristics which will be helpful to the differential diagnosis of hepatic MALT lymphoma.

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.

Contrast-Enhanced Ultrasound Features of Hepatic Reactive Lymphoid Hyperplasia: Correlation With Histopathologic Findings

OBJECTIVES

To find certain specifics of hepatic reactive lymphoid hyperplasia (HRLH) on contrast-enhanced ultrasound (CEUS) imaging as diagnostic imaging clues by retrospectively analyzing its enhancement features.

METHODS

From June 2010 to June 2017, 18 histopathologically confirmed HRLH lesions in 18 patients were included in this retrospective study. The lesion's location, maximum diameter, shape, margin, echogenicity, and color flow signal on conventional ultrasound (US) imaging and enhancement pattern, presence of a feeding artery, and donutlike enhancement on CEUS imaging were observed and recorded. The lesion size on CEUS imaging at peak enhancement and that on conventional US imaging were compared and recorded.

RESULTS

All of the lesions showed homogeneous hypoechogenicity with a regular well-defined margin on conventional US imaging, with a mean diameter ± SD of 14.3 ± 4.6 mm (range, 8-24 mm). On CEUS imaging, all of the lesions showed "quick-wash-in and quick-wash-out," which showed complete homogeneous hyperenhancement in the arterial phase and wash-out in the second half of the arterial phase or first half of the portal phase. In 83.3% (15 of 18) of the lesions, the lesion size that was enhanced at peak was enlarged compared with the hypoechoic area on conventional US imaging, and transient donutlike enhancement appeared when the lesion showed wash-out. In 55.6% (10 of 18) of cases, the feeding artery was detected.

CONCLUSIONS

Enlarged complete homogeneous hyperenhancement in the arterial phase, consequently followed by quick wash-out of the lesion and the appearance of donutlike enhancement, may be the CEUS features of HRLH.

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.

An unusual case of hepatic lymphoma with multiple epithelial malignancies

Primary hepatic mucosa-associated lymphoid tissue lymphoma (MALToma) is a rare entity. Its coexistence with other malignancies is even rarer. Only few case reports of its association with other malignancies mostly gastric and colon cancer have been published. We report a case of primary MALToma of liver in an unusual setting of dual solid malignancy.

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.

Hepatic Pseudolymphoma with Fluorodeoxyglucose Uptake on Positron Emission Tomography

A 69-year-old woman with chronic hepatitis B was admitted to our hospital with a hepatic tumor. The levels of 2 tumor markers, carcinoembryonic antigen and carbohydrate antigen 19-9, were slightly elevated; however, the α-fetoprotein and protein levels induced by vitamin K antagonist II were within the normal limits. Abdominal ultrasonography showed a well-defined peripheral hypoechoic mass that was isoechoic and homogeneous on the inside. Computed tomography showed a poorly enhanced tumor of 13 mm in diameter in the 5th segment of the liver. Fluorodeoxyglucose positron emission tomography showed a slight uptake (maximum standard uptake value 3.4) by the hepatic tumor. These findings suggested cholangiocellular carcinoma, and we performed anterior segmentectomy of the liver. A histopathological examination showed a hepatic pseudolymphoma. The patient's postoperative course was uneventful, and she remains alive without recurrence 5 months after undergoing surgery. In most cases, hepatic pseudolymphoma is preoperatively diagnosed as a malignant tumor and a definite diagnosis is made after resection. It is therefore necessary to consider hepatic pseudolymphoma as a differential diagnosis in patients with hepatic tumors.

Primary mucosa-associated lymphoid tissue lymphoma of the liver: A report of two cases and review of the literature

Mucosa-associated lymphoid tissue (MALT) lymphoma of the liver is a very rare condition and thus the diagnosis may be challenging. The clinical presentation is usually variable, ranging from minimal clinical symptoms to severe end stage liver disease. In this paper, we describe the clinicopathologic findings in two cases of primary hepatic MALT lymphoma. One case is an 80-year-old female with no underlying chronic liver disease and the second case is a 30-year-old female with autoimmune hepatitis complicated by MALT lymphoma. In both specimens, there was diffuse infiltration of atypical B-lymphocytes that were positive for CD20 and CD79a, but negative for CD5, CD43 and CD10. There were occasional lymphoepithelial lesions involving the hepatocytes or bile ducts. Polymerase chain reaction analysis showed monoclonal immunoglobulin heavy chain gene rearrangement in both cases. The first case was treated with surgery but developed pulmonary recurrence a year after complete resection but went into remission following treatment with rituximab. A second recurrence occurred in the right parotid gland 7 years later, which was treated with idelalisib. The second case was effectively treated with rituximab. To our knowledge, the second case is the first reported case linked to autoimmune hepatitis.