Case Of MALT Lymphoma Research Articles

Helicobacter pylori a karcinom žaludku

Helicobacter pylori belongs to the most common bacterial infections worldwide; despite its decreasing prevalence during the past four decades (currently ~ 40–50%), it is more prevalent in developing countries compared to developed ones. Intensive research of chronic Helicobacter pylori infection clarified the pathogenesis of several gastric and extragastric diseases, including different cancers. This review pointed out the role of Helicobacter pylori in different gastric malignancies. Chronic Helicobacter pylori infection is an etiological factor in non-cardia gastric cancer and most cases of low-grade MALT lymphoma of the stomach. However, there is an inverse association of Helicobacter pylori infection with other gastric malignancies, like cardia gastric cancer or rare hereditary Gastric Adenocarcinoma and Proximal Polyposis of the Stomach syndrome (GAPPS). A crucial issue has not been definitely solved yet: whether early eradication of Helicobacter pylori could prevent sporadic gastric cancer in the future? There is moderate evidence that searching for and eradicating Helicobacter pylori reduces the incidence of gastric cancer and death from gastric cancer in healthy asymptomatic infected Asian individuals, although data cannot necessarily be extrapolated to European or US populations so far. Indication for the eradication of Helicobacter pylori must now be considered with caution, on an individual basis of personalized medicine.

Concurrent primary extranodal marginal zone lymphoma and malakoplakia in the vagina: pearls and pitfalls

Primary lymphomas of the female genital tract are rare, representing approximately 1% of extranodal lymphomas. The most common histological subtype is diffuse large B-cell lymphoma, followed by follicular lymphoma. Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in the female genital tract is rare and usually discovered incidentally. While MALT lymphoma is often linked to infections or autoimmune diseases, its cause in the female genital tract is generally unknown. On the other hand, malakoplakia is a chronic inflammatory condition resulting from an impaired histiocytic response to common bacterial infections. In this report, we present an extremely rare case of concurrent primary MALT lymphoma and malakoplakia in the vagina of a 79-year-old woman who exhibited postmenopausal bleeding and a soft tissue mass. Tissue examination revealed malignant lymphoid cells obscured by abundant inflammatory cells interspersed with numerous blood vessels, mimicking granulation tissue. A significant diagnostic challenge lies initially in missing the concurrent presence of malignant lymphoma and malakoplakia. Therefore, we emphasize the importance of clinicopathological correlation to accurately diagnose these rare conditions.

Histological criteria for selecting patients who need clonality test for non-gastric MALT lymphoma diagnosis

The histological diagnosis of extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) is difficult for pathologists. Recently, digital pathology systems have been widely used to provide tools that can objectively measure lesions on slides. In this study, we measured the extent of marginal zone expansion in suspected MALT lymphoma cases and compared the results with those of a molecular clonality test. In total, 115 patients who underwent an IGH gene rearrangement test for suspected MALT lymphoma were included in this study. All cases were histologically classified into three patterns; “small lymphoid aggregates with no germinal center (Pattern 1),” “lymphoid follicles with germinal center (Pattern 2)” and " fused marginal zone or diffuse small lymphocytic proliferation (Pattern 3).” The proportions of monoclonality in Pattern 1, 2, and 3 were 25.0%, 55.0%, and 97.9%, respectively. The ratios of marginal zone thickness to germinal center diameter and entire lymphoid follicle area to germinal center area were measured in Pattern 2 cases using a digital pathology system. Combining the width cutoff of 1.5 and the areal cutoff of 3.5, the sensitivity, specificity, positive predictive value, and negative predictive value for MALT lymphoma were 96.97%, 70.37%, 80.00%, and 95.00%, respectively. In conclusion, through objective measurement of the marginal zone, suspected cases of MALT lymphoma requiring a molecular clonality test can be effectively selected.

A MALT LYMPHOMA PRESENTING WITH PRIMARY DIFFUSE RENAL INVOLVEMENT

The involvement of kidney in marginal zone lymphoma is not a frequent condition. Seventy-seven-year-old female presented with renal failure. Renal biopsy revealed diffuse lymphoid infiltration replacing the normal renal tissue. Immunohistochemical staining was CD20, CD38, kappa, IgD positive and CD3, lambda, cyclin D1, CD5, CD23, CD43 negative. Ki-67 was 10% positive. The patient was diagnosed as MALT type marginal zone lympho-ma. Body Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) performed for staging revealed diffuse FDG uptake in both kidneys and no lym-phadenopathy was detected. Bone marrow aspiration and biopsy were normal. Rituximab - bendamustin chemotherapy regimen was started. In conclusion, this is the first case of MALT lymphoma involving kidney diffusely which requires rapid diagnosis and treatment to prevent irreversible loss of renal functions.

S3968 Case of Suspected B-Cell MALT Lymphoma in Patient With Lynch Syndrome

S3968 Case of Suspected B-Cell MALT Lymphoma in Patient With Lynch Syndrome

S2246 A Rare Case of Helicobacter pylori Negative Primary MALT Lymphoma of the Rectum

S2246 A Rare Case of Helicobacter pylori Negative Primary MALT Lymphoma of the Rectum

Renal mucosa-associated lymphoid tissue lymphoma: a case report and literature review

Background: Renal MALT lymphoma is a rare entity with few reports in the literature. These neoplasms arise at extranodal sites, usually related with chronic inflammation due to infection or autoimmune disorder and share histologic and immunophenotypic features. To date, 10 cases of renal MALT lymphoma have been described. Case presentation: We present a case of a MALT renal lymphoma in a 69-year-old woman with suspected preoperative diagnosis of renal cell carcinoma (papillary vs chromophobe type), RENAL SCORE 9p. We performed a retroperitoneal laparoscopic left partial nephrectomy guided by intraoperative ultrasound. Conclusion: There are few reports in the literature regarding renal MALT lymphoma. We consider that this might be considered as a differential diagnosis of renal mass.

Suspected Case of MALT Lymphoma of the Nasal Turbinate in a Horse

We examined a female Kiso horse (a native Japanese horse breed) aged 2 years and 9 months with persisting nasal discharge that died due to lymphoma. Necropsy revealed masses in the left nasal cavity, left periorbital cavity, and left maxillary and mandibular areas. Histologically, the neoplastic tissues were composed of lymphoid and plasmacytoid cells, with immunoglobulin A (α and λ chains) production in the latter. The foci of large lymphoid cells were detected at some sites. All neoplastic cell types were positively stained in immunohistochemical staining for CD20. Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) was suspected on the basis of the presence of lymphoepithelial lesions, plasmacytic differentiation, and large-cell transformation. A history of chronic rhinitis may be linked to the development of this disorder.

S2171 A Case of Colorectal MALToma

Introduction: Non-Hodgkin lymphoma is classified as nodal and extranodal. Extranodal lymphoma frequently involves the stomach and is associated with H. Pylori infection. Colonic involvement, however, is rare. We present a case of MALT lymphoma that was found incidentally on colonoscopy. Case Description/Methods: A 73-year-old male with a history of diabetes presented for surveillance colonoscopy. Previous colonoscopy reports were unavailable, but the patient endorsed a history of benign polyps. Colonoscopy revealed a patchy area of inflammation and ulceration localized to the rectum and rectosigmoid colon. Biopsies demonstrated prominent lymphoid aggregates with inconclusive flow cytometry. He was referred to oncology who recommended further sampling. He underwent repeat colonoscopy 5 months later which demonstrated a 3 cm polyp in the cecum in addition to multiple segmental aphthae (uniform punctate lesions with surrounding erythema and central pallor) stretching from the distal sigmoid colon to the rectum. Pathology of the polyp demonstrated several lymphoid aggregates and rectosigmoid biopsies demonstrated prominent lymphoid aggregates that were positive for CD20, CD79a, BCL-2. Findings overall were consistent with extranodal marginal zone lymphoma. PET scan demonstrated diffuse lymphadenopathy, splenomegaly, and intense hypermetabolic activity throughout the colon. Stool studies were not obtained. The patient was recommended for chemotherapy with weekly rituximab which has been well tolerated to date. Discussion: Colorectal lymphoma is a rare occurrence, and represents less than 1% of all colorectal malignancies. Furthermore MALTomas present as primary colonic lymphomas in only 2.5% of cases. MALTomas predominate in men aged 50-70 years old and are associated with chronic immunosuppression and H. pylori infection when found in the stomach, although this does not necessarily hold true when found in the colon. Patients can present with symptoms of abdominal pain, obstruction, or GI bleeding. Endoscopic appearance of MALTomas is not well defined and can range from a single polypoid lesion to ulcerated mucosa or erosions. A combination of surgery, chemotherapy, and radiation is available for treatment of advanced disease.Primary colonic lymphoma is rare and there are only a few cases reported in the literature. Although rare, it is important to keep NHL in the differential when polypoid or ulcerated lesions are found on colonoscopy.

Pulmonary MALT lymphoma: Imaging findings in 18 cases and the associated pathological correlations

BackgroundPulmonary MALT lymphoma is a rare disease that is easily misdiagnosed. The objective of this study was to improve the understanding of pulmonary MALT lymphoma for clinicians. MethodsThe computed tomography (CT) scans of 18 patients (13 males and 5 females), aged 41-70 years (mean=55.6 years), with histologically proven pulmonary MALT lymphoma were retrospectively reviewed by two radiologists, and pulmonary imaging findings were described. Correlations between the pulmonary abnormalities and histopathological findings in 13 patients were retrospectively reviewed. ResultsElementary lesions were characterized by masses or mass-like areas of consolidation (15/18), nodules (5/18), air bronchograms (16/18), airway dilatation (7/18), cavitation (5/18), airways passing through the lesion (8/18), CT angiogram signs (12/14) and vessels passing through the lesion (12/14). Additional findings included multiple cysts (n = 1), pleural effusion (n = 1) and atelectasis (n = 1). Pulmonary abnormalities were correlated with pathological appearance. Pathological examination confirmed lymphomatous infiltration with a bronchovascular distribution but no vessel or airway destruction, which appeared on CT as the vessels/airways passed through lesions naturally. ConclusionsWe herein demonstrated the imaging findings for 18 cases of pulmonary MALT lymphomas by analyzing the corresponding pathologies. We also discovered that vessels/airways could pass through pulmonary MALT lymphoma lesions, which may be helpful for diagnosis. This disease should be considered when chest CT imaging shows multiple/single masses or nodules or mass-like areas of consolidation together with vessels/airways passing through lesions.

A Case of Primary Tracheal MALT Lymphoma Treated as Chronic Cough of Unknown Cause with a Delayed Diagnosis

A Case of Primary Tracheal MALT Lymphoma Treated as Chronic Cough of Unknown Cause with a Delayed Diagnosis

EXTENSIVE CYSTIC LUNG DISEASE IN EXTRANODAL MARGINAL ZONE B CELL LYMPHOMA (MALT LYMPHOMA) OF THE LUNG WITH LIGHT CHAIN DEPOSITION DISEASE

TOPIC: Diffuse Lung Disease TYPE: Fellow Case Reports INTRODUCTION: Extranodal marginal zone lymphoma of mucosa associated lymphoid tissue (MALT Lymphoma) is a rare disorder, but is the most common cause of primary pulmonary lymphoma involvement. Cystic changes along with nodularity has been previously reported in MALT lymphomas along with light chain deposition disease (LCDD). CASE PRESENTATION: A 44 y/o previously smoking female patient presented with a 3-year history of progressive dyspnea in the setting of extensive cystic lung disease. Her extensive lung cysts had previously raised concern for lymphangioleiomyomatosis (LAM) and she had undergone an open lung biopsy (OLB) about 2 years prior. She also had a 10-year history of Rheumatoid Arthritis (RA) for which she had previously received methotrexate, adalimumab and leflunomide. The OLB was negative for LAM, but no alternative diagnosis was made based on the biopsy results. Due to progressive dyspnea, she presented to our facility where a fresh evaluation of her case was undertaken. A repeat CT Chest again confirmed extensive cystic lung changes that were not present 12 years ago and had minimally progressed from the time of OLB two years ago (figure 1). Pulmonary function testing (PFTs) showed a severe obstructive pattern with a positive bronchodilator response. Laboratory testing confirmed positive results for rheumatoid factor, CCP, ANA as well as SSA & SSB antibodies. A review of the OLB confirmed the presence of an atypical lymphoplasmacytic infiltrate associated with nodular kappa light chain deposition disease (LCDD). The overall pattern was consistent with extranodal marginal zone lymphoma of mucosa associated lymphoid tissue (MALT lymphoma). The biopsy confirmed the presence of cystic changes within the nodular light chain deposits. PET scan was negative for extrathoracic lymphoma and the patient was started on Rituximab. DISCUSSION: We present a case of pulmonary MALT Lymphoma with LCDD presenting with extensive cystic lung disease and severe airflow obstruction. The case was initially mistaken for LAM and appropriate therapy was delayed for 2 years. MALT lymphomas with LCDD are rare causes of pulmonary cystic disease and generally have a good prognosis with an overall 5-year survival rate exceeding 80% and a median survival over 10 years. Given the positive Sjogren's antibodies and the presence of lung cysts; lymphocytic interstitial pneumonia (LIP) was also considered in the differential diagnosis. The presence of severe airflow obstruction on lung function was somewhat atypical in this case and a component of bronchiolitis obliterans from RA could not be entirely excluded. CONCLUSIONS: Extranodal marginal zone B cell lymphoma of the lung can present with extensive cystic lung disease that can mimic other common causes of cystic lung disease such as LAM, LIP and Birt Hogg Dube disease and PLCH. Prognosis is generally good and Rituximab is the most commonly used initial treatment approach. REFERENCE #1: pulmonary and nodular cystic light chain deposition disease: a retrospective review of 10 cases. Baqir M et al. Respir Med. 2020 Apr; 164:105896. REFERENCE #2: Nodular pulmonary light chain deposition disease: an entity associated with Sjögren syndrome or marginal zone lymphoma. Arrossi AV et al. J Clin Pathol. 2016 Jun; 69(6): 490-6. REFERENCE #3: Pulmonary mucosa-associated lymphoidtissue lymphoma revisited. Borie R et al. Eur Respir J 2016; 47: 1244-1260. DISCLOSURES: No relevant relationships by Vaibhav Ahluwalia, source=Web Response No relevant relationships by Hasan Ahmad Hasan Albitar, source=Web Response No relevant relationships by Vivek Iyer, source=Web Response

Clinicopathological aspects of primary mucosa-associated lymphoid tissue lymphoma of the salivary gland: A retrospective single-center analysis of 72 cases.

Salivary gland extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) is uncommon and has not been studied extensively. We aimed to investigate the features of clinicopathological and molecular changes of salivary MALT lymphoma. Seventy-two cases of primary salivary MALT lymphoma that had clinicopathological information available were utilized in this study. MALT1 gene translocation, trisomy 3, and trisomy 18 were detected by interphase fluorescence in situ hybridization (FISH). The data were analyzed using SPSS 17.0 software package. The ratio of male to female was 1:2.8, and the median age was 57.0years. 12.5% (9/72) of the patients presented with multiple swellings. Among the others with solitary mass, the parotid gland was involved most frequently (47/63,74.6%), followed by the palate (7/63, 11.1%). 34.7% of patients had an autoimmune disease, with Sjögren syndrome (SS) being the most common. Among the 70 cases successfully performed, it was identified that trisomy 3 was the most frequent molecular change (41/70, 58.6%), followed by trisomy 18 (7/70, 10%) and MALT1 translocation (5/70, 7.1%). The tumor tissue tended to exhibit trisomy 3 in patients without SS (p=0.038). The 5-year overall survival was 94.1%, and the 5-year disease-free survival was 85.3% (mean follow-up time: 104.7months). The patients without SS and trisomy 18 had a prolonged recurrence-free survival (p=0.015, p=0.001 respectively). Salivary gland MALT lymphoma is associated with autoimmune diseases, and trisomy 3 is the most common genetic change. Trisomy 18 can be used to predict the possibility of tumor relapse.

Clinical Features and Prognoses of IgG4-Positive and IgG4-Negative Lacrimal Lymphomas.

Purpose: The clinical characteristics and prognoses of immunoglobulin G4-positive (IgG4+) and IgG4-negative (IgG4−) lacrimal lymphomas were comparatively analyzed to screen for clinical indicators with differential diagnostic significance.Methods: This was a retrospective and single-center clinical study. From June 2011 to June 2018, clinical data of 39 patients with lacrimal lymphoma, diagnosed by histopathology were collected from the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University.Results: According to inclusion and exclusion criteria, 30 (76.9%) were in the IgG4− group and 9 (23.1%) were in the IgG4+ group. In the IgG4+ group, the sex ratio of male to female was 2:1 and the mean age was 56.67 ± 13.29 years old. In the IgG4− group, the sex ratio of male to female was 3.29:1 and the mean age was 61.47 ± 12.87 years old. Statistical analysis of the clinical indicators showed significant differences between the two groups in affected eye, preoperative history of glucocorticoids, ocular nerve thickening, the expression of serum IgG4 and prognosis (P < 0.05). There was no significant statistical difference in laboratory indicators between the two groups, including C3, C4, RF, ASO, CRP, IgA, IgM, IgG, IgG1, IgG2, and IgG3 (P > 0.05). The event-free cumulative percentages at 3 and 5 years for the 39 lacrimal lymphomas were 81.1 and 62.4%, respectively, with recurrence and death as end events. In 34 lacrimal gland MALT lymphoma cases, the event-free cumulative percentages at 3 and 5 years were 84.4 and 69.1%, respectively. In the IgG4+ and IgG4− groups, the event-free cumulative percentages at 3 years were 75.0 and 87.7%, respectively. The event-free cumulative percentage at 5 years was 62.6% in the IgG4-group and insignificant in the IgG4+ group. There was no statistical difference in event-free cumulative percentage between the two groups (P = 0.983).Conclusion: The pathogenesis and disease characteristics of IgG4-positive lacrimal lymphoma may differ from IgG4-negative lacrimal lymphoma, but the positive expression of IgG4 may not have significant influence on the recurrence of lacrimal lymphoma.

Involvement of non-Helicobacter pylori helicobacter infections in Helicobacter pylori-negative gastric MALT lymphoma pathogenesis and efficacy of eradication therapy.

Eradication therapy is known to be effective against Helicobacter pylori-positive gastric MALT lymphoma but predicting the efficacy of eradication therapy against Helicobacter pylori-negative gastric MALT lymphoma is difficult. Recent reports have shown that non-Helicobacter pylori helicobacter infections induce gastric MALT lymphoma, and we aimed to clarify whether non-Helicobacter pylori helicobacter infections are associated with the efficacy of eradication therapy. We analyzed eradication therapy as a first-line treatment for 182 cases of gastric MALT lymphoma, classified according to Helicobacter pylori infection and API2-MALT1 mutation status. We also evaluated the non-Helicobacter pylori helicobacter infection status in 29 Helicobacter pylori-negative cases via PCR with DNA extracted from paraffin-embedded biopsy tissues. Finally, we analyzed the relationship between non-Helicobacter pylori helicobacter infection status and eradication therapy outcome. The API2-MALT1 mutation was observed in 13/182 patients (7.1%), none of whom were cured by eradication therapy. Helicobacter pylori-negative cases had a significantly higher non-Helicobacter pylori helicobacter infection rate than Helicobacter pylori-positive cases (16/29, 55% vs. 3/29, 10%; P < 0.05). Among the Helicobacter pylori-negative cases, non-Helicobacter pylori helicobacter-positive cases had a significantly higher complete response rate than non-Helicobacter pylori helicobacter-negative cases (12/16, 75% vs. 3/13, 23%; P < 0.05). Helicobacter pylori-negative and API2-MALT1-negative gastric MALT lymphoma cases exhibited a high rate of non-Helicobacter pylori helicobacter infections, which may have contributed to the success of eradication therapy. Therefore, we recommend eradication therapy as a first-line treatment for non-Helicobacter pylori helicobacter-positive gastric MALT lymphoma.

Monotypic Plasma Cell Proliferation of Uncertain Clinical Significance Mimicking Interstitial Cystitis: An Early Lesion of MALT Lymphoma?

We prospectively studied our institutional experience of bladder extranodal marginal zone (mucosa-associated lymphoid tissue [MALT]) lymphoma including bladder biopsies in which the possibility of MALT lymphoma was considered. We identified a subset of cases primary to the urinary bladder, presenting with prominent plasma cell infiltrates and symptoms mimicking bladder pain syndrome/interstitial cystitis. These proliferations were designated for this study as "monotypic plasma cell proliferation of uncertain clinical significance" (MPCP-US), as the features were insufficient for diagnosis of MALT lymphoma. We identified 33 patients, consisting of 22 cases of MPCP-US (6 of which were associated with amyloid deposition) and 11 cases of MALT lymphoma. MPCP-US was more prevalent in men (73%), a mass lesion was not identified at cystoscopy, and only 1 case had an accompanying urinary tract infection (4.5%). Histologically, MPCP-US presented as monotypic plasma cells arranged in a superficial band-like distribution in the lamina propria, predominantly kappa restricted (68%) and IgA+ or IgM+ (64% and 23%, respectively) and without a histologic mass of atypical B cells or plasma cells, not diagnostic for established MALT lymphoma or plasmacytoma. Secondary involvement of the bladder by other lymphoproliferative disorders was excluded and there was no evidence of progressive disease. MALT lymphomas are presented for comparison and our analysis demonstrated that MPCP-US represent a different clinicopathologic entity compared with classic MALT lymphoma. We present the first series of cases of MPCP-US. The recognition of this entity is fundamental to the development of management protocols to relieve intractable symptoms mimicking bladder pain syndrome/interstitial cystitis in these patients.

Lacrimal Gland Orbital Lobe Cystic Mucosa-Associated Lymphoid Tissue Lymphoma: Case Report and Literature Review

This report describes a case of cystic, extranodal, marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue of the orbital lobe of the lacrimal gland in a 70-year-old female. Case of cystic MALT lymphoma isolated to the orbital lobe of the lacrimal gland are rare, with six case reported in the literature. Initial clinical examination revealed bilateral dermatochalasis and a medial left upper lid contour deformity thought to be involutional ptosis. There was no suspicion for a mass lesion. Imaging and subsequent specialist clinical, pathologic, an immunochemical evaluation showed diagnostic features of cystic lacrimal gland orbital lobe MALT lymphoma. Clinical, radiographic, and immunohistopathologic and immunohistochemical findings are detailed. A review of literature was performed and discussed.

A Case of Laryngeal MALT Lymphoma that Disappeared Spontaneously

A Case of Laryngeal MALT Lymphoma that Disappeared Spontaneously

T(3;14)(p14.1;q32)/FOXP1-IGH translocation in thyroid extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

ObjectivesMALT lymphoma occurs in various organs and has several characteristic genetic aberrations. Thyroid MALT lymphoma has been reported to include t(3;14)(p14.1;q32)/FOXP1-IGH as a specific genetic aberration, but the number of studies is limited. Method and resultsWe examined 86 thyroid lymphoma cases using fluorescence in situ hybridization (FISH) for the detection of t(3;14)/FOXP1-IGH in formalin fixed paraffin-embedded tissue (FFPE). Histopathological diagnoses of the analyzed specimen were as follows: thyroid MALT lymphoma (n = 59), DLBCL (n = 23), follicular lymphoma (n = 4), and benign lesions (n = 14) included Hashimoto’s thyroiditis (n = 13) and other (n = 1). Of the 100 analyzed cases, thirty-six (36 %) thyroid lymphoma cases were positive for t(3;14)/FOXP1-IGH. Thirty-three (55.9 %) of the 59 MALT lymphoma cases were positive for t(3;14)/FOXP1-IGH. Three (13.0 %) of the 23 DLBCL cases were positive for t(3;14)/FOXP1-IGH. All 4 follicular lymphomas examined were negative for t(3;14)/FOXP1-IGH. None of the benign cases was positive for t(3;14)/FOXP1-IGH, including Hashimoto's thyroiditis (0/13) and benign tissue (0/1). ConclusionsOur study found that t(3;14)/FOXP1-IGH was frequently found in thyroid MALT lymphoma. A detection of t(3;14)/FOXP1-IGH is extremely useful for the differential diagnosis between primary MALT lymphoma of the thyroid and other thyroid disorders.

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.