Low-grade Mucosa-associated Lymphoid Tissue Research Articles

Primary Esophageal Lymphoma: A Histopathological Experience from Two Tertiary Hospitals, Western Saudi Arabia.

Primary esophageal lymphoma (PEL) is a rare disorder. The objective of this study was to document the clinicopathological features of PEL at two tertiary hospitals in the western region of the Kingdom of Saudi Arabia. All PELs diagnosed between May 2002 and June 2022 were retrieved. Histopathological and immunohistochemical slides were reviewed. Additional immunohistochemistry stains were performed in selected cases. Follow-up data were collected. There were only eight cases of PEL in the records of the two hospitals. The age of the patients ranged between 50 and 74 years (median 62 years and mean 62.5 years). There were six males (80%) and two females (20%). None of the patients were immunocompromised or had human immunodeficiency virus (HIV) infection. The clinical manifestation included dysphagia and loss of weight. Six cases were diffuse large B-cell lymphoma (DLBCL), and two were low-grade mucosa-associated lymphoid tissue lymphoma. PEL is an extremely rare disease with male predominance. DLBCL is the most common pathological type in our community. There was no relation to immune status or HIV infection in this series. Clinical presentations were typically dysphagia with weight loss. Further reporting of PEL cases might help explain this disease and improve its diagnosis and management.

AN UNUSUAL CASE OF PULMONARY CAVITARY LESIONS IN AN IMMUNOSUPPRESSED PATIENT

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: The differential diagnosis of pulmonary cavitary lesions is broad. They can be categorized in to infectious and non-infectious diseases, including neoplasms. Among malignancies, squamous cell carcinoma is a common cause of lung cavitation (1). Herein, we report a rare case of primary pulmonary diffuse large B-cell lymphoma (DLBCL) in a patient with rheumatoid arthritis that presented with multiple cavitary lesions and hypercalcemia. CASE PRESENTATION: 83-year-old male presented with hemoptysis, dyspnea, confusion, and constipation for several weeks. His past medical history was significant for tobacco abuse and interstitial lung disease from rheumatoid arthritis (RA) treated with methotrexate. CT chest showed bilateral cavitary lung lesions, left-pneumothorax and pneumomediastinum, needing chest-tube placement. Pulmonary function test showed a mild restrictive defect with a severe reduction in diffusion capacity. Labs showed hypercalcemia of 13.7 mg/dl, suppressed parathyroid hormone (PTH), elevated PTH-related peptide (PTHrp), and 1-25(OH) 2 Vitamin-D level. Quantiferon gold, sputum acid-fast bacilli and cultures were negative. Blood cultures (1/4 bottles) grew Actinomyces viscosus that was treated with 6-weeks of piperacillin-tazobactam. Bronchoscopy with lavage was unrevealing; however, due to a suspicion for malignancy with elevated PTHrp level, a CT-guided biopsy of left lower lobe lung mass was performed that confirmed a diagnosis of DLBCL, non-germinal center B-cell type. DISCUSSION: Pulmonary lymphoma is very rare and presents with nonspecific pulmonary symptoms (2). The pathogenesis of primary pulmonary DLBCL remains elusive. Patients with autoimmune disorders and recurrent bacterial infections are at a higher risk for developing DLBCL. Chest imaging may show nodular lesions, consolidation or interstitial /mixed alveolar infiltrates (2). DLBCL presenting with multiple cavitary lesions, is rarely reported. In our patient hypercalcemia was mediated by elevation of both PTHrp and 1-25(OH)2 Vitamin-D, which is unusual. Most primary pulmonary lymphomas (PPL) are low-grade mucosa-associated lymphoid tissue (MALT)-type, compared to more aggressive pulmonary diffuse large B-cell lymphoma (DLBCL), which is very uncommon (3). Most likely, our patient's autoimmune disorder (RA) and chronic methotrexate use contributed in the development of his DLBCL. CONCLUSIONS: We report a rare case of primary pulmonary DLBCL that manifested with multiple cavitary lesions and hypercalcemia. DLBCL must be considered in the differential diagnosis of cavitary lung lesions particularly in immunosuppressed patients. Reference #1: Chaudhuri MR. Primary pulmonary cavitating carcinomas. Thorax. 1973;28:354-366 Reference #2: Fujita N, Ando M, Goto A, Sakata M, Ogata M, Usagawa Y, et al. Diffuse large B-Cell lymphoma arising from the lesion of chronic lobar atelectasis. Tohoku J Exp Med. 2020;250(2):129–35. Reference #3: Brown S, Horton J, Rosario D, Dorsey DA, Hetz S, King CS. High-grade primary pulmonary B cell lymphoma presenting as a Necrotic mass. Respir Care. 2011 Jun 1;56(6):871–3. DISCLOSURES: No relevant relationships by Haytham Adada, source=Web Response no disclosure on file for Mahmoud Amarna; No relevant relationships by Pavan Annamaraju, source=Web Response No relevant relationships by Camelia Chirculescu, source=Web Response No relevant relationships by Nino Nemsadze, source=Web Response No relevant relationships by Sana Yakoob, source=Web Response

A case of Barrett\u2019s esophageal cancer with gastric mucosa-associated lymphoma

BackgroundAlthough the first-line therapy for early-stage gastric mucosa-associated lymphoid tissue lymphoma is the eradication of Helicobacter pylori, the effect of eradication in Helicobacter pylori-negative cases is unclear. In this case report, we describe a surgical option for a case of Barrett’s esophageal cancer with concurrent gastric mucosa-associated lymphoid tissue lymphoma.Case presentationA 79-year-old man was admitted to our hospital with Barrett’s esophageal cancer and gastric mucosa-associated lymphoid tissue lymphoma. Initially, we performed endoscopic submucosal dissection for Barrett’s esophageal cancer. Since residual tumor was observed after the endoscopic submucosal dissection, we performed an esophagectomy with two-field lymph node dissection, which was followed by placement of a gastric conduit via the posterior mediastinal route. He was discharged 14 days after surgery. Although no additional treatment exists for mucosa-associated lymphoid tissue lymphoma, no recurrent disease has been detected to date.ConclusionAn option to use a portion of the stomach with low-grade malignant mucosa-associated lymphoid tissue lymphoma as a conduit after esophagectomy was suggested.

Low-grade gastric mucosa-associated lymphoid tissue lymphoma: Clinicopathological factors associated with Helicobacter pylori eradication and tumor regression.

353 Background: Eradication of Helicobacter pylori is widely accepted as the initial therapy for low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The aim of this study was to assess the remission and relapse rates of low-grade gastric MALT lymphoma after H. pylori eradication and to identify the clinical factors affecting remission. Methods: We retrospectively analyzed 151 patients diagnosed with gastric MALT lymphoma from May 2003 to December 2018. Results: Of the 151 patients, 112 (74.2%) had an H. pylori infection. Total regression rates with eradication was 90.2% (101/112) in H. pylori-positive patients and 55% (11/20) in H. pylori-negative patients. Age, sex, tumor location, endoscopic findings, and the severity of mononuclear lymphocytes were not related to achieving successful initial H. pylori eradication and remission. However, patients with a smaller H. pylori burden ( p=0.030) and less neutrophil infiltration ( p=0.003) were more likely to achieve a successful initial H. pylori eradication. H. pylori ( p<0.001) and the burden ( p=0.020) were significantly related to remission of MALT lymphoma. Conclusions: The results show that H. pylori burden and neutrophil infiltration were inversely related to the success of the initial H. pylori eradication procedure and that the H. pylori burden was inversely related to the remission of MALT lymphoma.

3229 Helicobacter pylori-Negative Gastric Mucosa-Associated Lymphoid Tissue Lymphomas: A Challenge in Treatment Options

INTRODUCTION: Primary gastric lymphoma is a rare entity of which the specific variant, mucosa-associated lymphoid tissue (MALT) lymphomas may be the best recognized given its association with Helicobacter pylori (H. pylori) infection. It has been thought that repetitive immune stimulation from underlying infection is influential in the pathogenesis of this tumor. However up to 10% of gastric MALT lymphomas are diagnosed without a concomitant H. pylori infection. The pathogenesis and management of H. pylori-negative gastric MALT lymphomas remains uncertain. CASE DESCRIPTION/METHODS: 65 year old woman with Celiac disease and GERD presented with worsening severe reflux and epigastric pain. She underwent EGD which revealed multiple superficial ulcers in the cardia with notable nodularity, ulceration, and friability. Cold forceps biopsies of the abnormal mucosa demonstrated diffuse atypical small B-Cell lymphoid infiltrate with features compatible with low grade MALT lymphoma. Of note, immunostain for H. Pylori was negative. Subsequent H. pylori stool antigen assay as well H. pylori IgG, IgM, and IgA were all negative. Given her negative antibodies indicating she truly had no exposure to H. Pylori, the patient has been referred to oncology for multidisciplinary management. DISCUSSION: This case of early stage gastric MALT lymphoma without evidence of active H. pylori infection elucidates that there is limited literature for the management for these patients. Studies have suggested that H. pylori eradication therapy can be efficacious for a proportion of H. pylori-negative gastric MALT lymphomas, possibly due to a false negative detection by biopsy. Local radiation therapy with curative intent and single agent rituximab therapy rather than H. pylori eradication have also been explored as alternate options. The data stems from retrospective studies and single agent prospective trials. Thus, there may be a role for future research directly comparing treatment strategies for optimal management of this clinical entity.

1081P - Efficacy of salvage therapy in the treatment of Helicobacter pylori-positive gastric low-grade mucosa-associated lymphoid tissue lymphoma

BackgroundHelicobacter pylori (H.pylori) infection has a critical role in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and its eradication can lead to tumor regression. However, in patients who do not achieve a lymphoma regression or relapse following antibiotic therapy, outcome of the patients are scarce. We evaluated the long-term outcome of the patients who received salvage therapy with relapsed or refractory gastric MALT lymphoma. MethodsBetween June 2000 and June 2017, a total of 29H.pylori-positive gastric MALT lymphoma patients who received frontline H.pylori eradication were included in this study. H.pylori-positive status was defined by positive results for the biopsy urease test and histology. They had all been diagnosed by endoscopy and had a complete staging including CT-scan. Patients received standard triple therapy for eradication of H.pylori and after treatment were sequentially followed-up with endoscopies performed to evaluate the response. Tumors that had resolved to complete remission (CR) score of GELA histologic grading system were considered treatment-responsive. ResultsDuring the follow-up periods 16 patients were refractory, nine had probable minimal residual disease and four relapsed after the first-line antibiotics. Of these 29 patients, transformation into high-grade B-cell lymphoma did not occur. Among the non-responder and relapsed patients, three patients were subjected to a watch and wait, while 26 patients underwent second-line treatment including radiotherapy (n=20), chemotherapy (n=5), chemotherapy plus sequential radiotherapy (n=1). Of the 20 patients treated with radiotherapy, the median dose to stomach was 3060 cGy (range, 1620-5000 cGy). After radiotherapy a CR was achieved in 20 patients (100%). Among six patients who received chemotherapy, a CR was achieved in five patients and no change was in one. That patient was achieved CR after radiotherapy. Probabilities of freedom from treatment failure and overall survival after 10 years were 100% and 83%. ConclusionsOutcome of patients with first-line H.pylori eradication failure followed by delayed chemotherapy and/or radiotherapy on indication was excellent. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Characterization and outcomes of local treatment for primary bladder lymphoma: A population-based cohort analysis.

Introduction:Primary bladder lymphoma (PBL) is rare, representing 0.2% of extranodal lymphoma and less than 1% of all tumors originating in the bladder. Since the initial description of the disease, low-grade mucosa-associated lymphoid tissue (MALT) lymphoma has been reported as the most common subtype while high-grade disease was thought to represent only 20% of the reported cases.Materials and Methods:One hundred and ninety five patients with PBL from the Surveillance, Epidemiology, and End Results (SEER) registry from 1998-2010 were reviewed. Tumors were classified as high or low grade based on histologic subtype of lymphoma based on revised European-American Lymphoma classification system. Socio-demographic and clinical variables were reported, as well as survival outcome analyses using the Kaplan-Meier method and log-rank test. Cox proportional hazard analysis was used to generate hazard ratios for risk factors associated with mortality.Results:Eighty-three patients (42.6%) with low-grade and 112 patients (57.4%) with high-grade bladder lymphoma were studied. There were no differences between the low and high-grade groups for socio-demographic or clinical variables. Median overall survival or patients with low-grade disease was 38 months versus 15 months for patients with high-grade disease (p< 0.001). Analysis demonstrated worse survival outcomes for patients with high-grade disease compared to low-grade disease (p< 0.001). On multivariable analysis, increasing age and high-grade disease were associated with worse disease specific mortality (p< 0.001).Conclusion:Patient with high-grade primary bladder lymphoma had worse survival outcomes compared to those with low-grade disease. While transurethral resection provides tissue for diagnosis, immunotherapy/chemotherapy remains the mainstay of treatment for bladder lymphoma. Consolidation chemotherapy has been recommended in young patients not achieving complete remission with immunotherapy/chemotherapy.

Management for primary thyroid lymphoma: Experience from a single tertiary care centre in Taiwan

Abstract Background Diverse treatments are available for different histological types of thyroid lymphoma: concurrent chemoradiotherapy for diffuse large B cell lymphoma (DLBCL) and radiotherapy or thyroidectomy for low-grade mucosa-associated lymphoid tissue (MALT) lymphoma. However, diagnosing lymphomas before operation is difficult, because the diagnostic yield of fine-needle biopsies is limited by the rarity of the disease. Therefore, patients may undergo unnecessary thyroidectomies. Purpose To investigate the efficacy of various biopsy procedures and explore indications for thyroidectomy in patients with primary thyroid lymphomas. Methods The demographics, types of biopsy procedures, treatments, and outcome data of patients diagnosed with primary thyroid lymphoma at Tri-Service General Hospital between 1992 and 2015 were retrospectively collected. Results Ten patients received a diagnosis of primary thyroid lymphomas: eight with DLBCL and two with MALT lymphoma. None of these patients received a definitive diagnosis after fine-needle aspiration biopsies; however, six patients received their diagnosis and histological-subtype classification after core-needle biopsies. Before 2004, three patients with DLBCL underwent thyroidectomies for diagnostic purposes and one encountered vocal cord palsy. By contrast, two patients with localized MALT lymphoma underwent thyroidectomies for treatment, with both experiencing favorable outcomes and prognoses. Conclusion Core-needle biopsy is superior to fine-needle biopsy for diagnosing primary thyroid lymphomas without increasing complications. Thyroidectomy in localized, low-grade MALT lymphoma of the thyroid can cure the disease and exclude high-grade malignancies in the remaining glands. By contrast, DLBCL should be treated with chemotherapy and radiotherapy after diagnosis through biopsy, and extensive surgery should be avoided.

Efficacy of frontline antibiotics therapy in the treatment of Helicobacter pylori-negative gastric low-grade mucosa-associated lymphoid tissue lymphoma.

e19024Background: Previous series reports revealed that certain proportions of Helicobacter pylori (HP)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma may respond to antibiotics...

Gastric Mucosa-associated Lymphoid Tissue Lymphoma Based on Outcome of Domestic Treatment

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is associated with Helicobacter pylori infection. H. pylori eradication can be performed as a primary therapy regardless of H. pylori status. In Korea, six articles were published about low-grade gastric MALT lymphoma with H. pylori. Complete regression rate after H. pylori eradication is reported at 74.5% to 94.4%. Radiotherapy results in favorable clinical long-term outcomes in patients with early-stage gastric MALT lymphoma who fail H. pylori eradication therapy and those who are H. pylori negative. Chemotherapy could be reserved for patients with metastatic or high-grade lymphoma. In gastric MALT lymphoma, patients with polypoid type on initial endoscopy had a higher likelihood of recurrence than those with diffuse infiltration or ulceration types. The depth of invasion, location of lesions, and chromosomal abnormality with t(11;18) together are predictive factors for failure to remission by H. pylori eradication.

Chemotherapy Alone Is Effective to Treat Localized and Disseminated Ocular Adnexa Lymphomas

Background:The treatment strategies for ocular adnexa lymphomas (OALs), including conjunctiva, orbital, and lacrimal gland lymphomas, remain controversial. In this study, we assessed the efficacies and outcomes of different modality treatment, including chemotherapy, radiotherapy, and surgery for OALs.Methods and Materials:Between Jan. 1990 to Dec. 2013, patients receiving first-line chemotherapy (oral alkylating agents, rituximab-based treatment, or CHOP [cyclophosphamide, doxorubicin, vincristine, and steroid]-like regimens), radiotherapy (30 to 50 Gy, in 1.8- to 2.0- Gy per daily fractions), and surgery for newly diagnosed OAL were included in this study. The clinicopathologic features, including patients' characteristics, primary lymphoma locations, pathology subtypes, treatment modality, event-free survival (EFS) following first-line therapy, and OS (OS) were analyzed.Results:There were 56 men and 37 women with median age of 58 years were included. Of them, 79 patients (85%) were diagnosed with low-grade mucosa-associated lymphoid tissue (MALT) lymphoma, 5 (5%) with high-grade transformed MALT lymphoma, and 9 (10%) with diffuse large B cell lymphoma. Orbit was the most common involved location (45 patients, 48%), followed by conjunctiva (35 patients, 38%), and lacrimal gland (13 patients, 14%). Of 79 patients with stage I-IIE1 disease, 22 received chemotherapy, 34 with radiotherapy, and 23 patients with other modality treatments (18 with surgery, 4 with combined radiotherapy and chemotherapy, and 1 with intra-lesional injection of rituximab). The 5-year EFS for chemotherapy, radiotherapy, and other modality treatment was 89.2%, 89.7%, and 83.1%, respectively, whereas the 5-year OS for chemotherapy, radiotherapy, and other modality treatment was 100%, 90.4%, and 87.5%, respectively. Of 14 patients with stage IIE2 to IV disease, the 5-year EFS for chemotherapy alone (n=9) and combined radiotherapy and chemotherapy (n=5) were 68.6%, 80%, respectively, whereas the 5-year OS for both group was 80.0%. Among 42 patients receiving radiotherapy, 7 (16.7%) patients developed cataract, 4 (9.5%) patients with keratitis, and 2 (4.8%) patients with maculopathy. In multivariate analysis, high-grade transformation (P=0.049) was the significant factor for shorter EFS of 1st -line treatment. Old age (> 60 years) (p = 0.014), advanced stage (stages III and IV) (p = 0.03), and high-grade transformation (p = 0.018) were the prognostic factors of poor OS.Conclusions:In addition to radiotherapy, our data indicate that chemotherapy as first-line therapy provides good disease control and less radiotherapy-associated side effects for patients with stage I to IIE1 OALs. Old age, advanced stage, and high-grade histology subtype remain poor prognostic factors for OALs, and new treatment strategies for these patients are warranted. DisclosuresNo relevant conflicts of interest to declare.

Gastric de novo Muc13 expression and spasmolytic polypeptide-expressing metaplasia during Helicobacter heilmannii infection.

Helicobacter heilmannii is a zoonotic bacterium that has been associated with gastric disease in humans. In this study, the mRNA expression of mucins in the stomach of BALB/c mice was analyzed at several time points during a 1-year infection with this bacterium, during which gastric disease progressed in severity. Markers for acid production by parietal cells and mucous metaplasia were also examined. In the first 9 weeks postinfection, the mRNA expression of Muc6 was clearly upregulated in both the antrum and fundus of the stomach of H. heilmannii-infected mice. Interestingly, Muc13 was upregulated already at 1 day postinfection in the fundus of the stomach. Its expression level remained high in the stomach over the course of the infection. This mucin is, however, not expressed in a healthy stomach, and high expression of this mucin has so far only been described in gastric cancer. In the later stages of infection, mRNA expression of H(+)/K(+)-ATPase α/β and KCNQ1 decreased, whereas the expression of Muc4, Tff2, Dmbt1, and polymeric immunoglobulin receptor (pIgR) increased starting at 16 weeks postinfection onwards, suggesting the existence of spasmolytic polypeptide-expressing metaplasia in the fundus of the stomach. Mucous metaplasia present in the mucosa surrounding low-grade mucosa-associated lymphoid tissue (MALT) lymphoma-like lesions was also histologically confirmed. Our findings indicate that H. heilmannii infection causes severe gastric pathologies and alterations in the expression pattern of gastric mucins, such as Muc6 and Muc13, as well as disrupting gastric homeostasis by inducing the loss of parietal cells, resulting in the development of mucous metaplasia.

Endocytoscopic findings of lymphomas of the stomach.

BackgroundThe gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy.MethodsEndocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma.ResultsOn conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression.ConclusionsOn endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Imaging of Primary Gastrointestinal Lymphoma

Primary gastrointestinal (GI) lymphoma most often arises from stomach, small bowel, or colon. The 2 most common subtypes of primary GI lymphoma include low-grade mucosa-associated lymphoid tissue lymphoma, strongly associated with Helicobacter pylori infection, and high-grade diffuse, large B-cell lymphoma. Primary GI lymphoma demonstrates a myriad of imaging manifestations that can commonly mimic other pathologies. Timely and accurate diagnosis remains important because treatment and prognosis of primary GI lymphoma differ significantly from other GI malignancies and even lymphoma of other primary sites.

Eradication Therapy in Helicobacter pylori-negative, Gastric Low-grade Mucosa–associated Lymphoid Tissue Lymphoma Patients

To assess the remission rate of gastric low-grade B-cell mucosa-associated lymphoid tissue lymphoma after an eradication therapy in Helicobacter pylori-negative patients. We performed a systematic review with pooled analysis of published studies. Data were analyzed according to: (1) number of H. pylori-negative patients treated with only eradication therapy; (2) number of patients in whom the complete lymphoma remission was achieved; and (3) the method used to exclude H. pylori infection. Overall, 11 studies with 110 patients met the inclusion criteria for this pooled analysis. H. pylori infection was excluded in all studies with at least 3 different diagnostic tests. Eradication therapy achieved a complete lymphoma regression in 17 (15.5%; 95% confidence interval, 8.7-22.2) patients. Eradication therapy is successful in a small but distinct subgroup of H. pylori-negative patients with low-grade mucosa-associated lymphoid tissue lymphoma. On the basis of the generally indolent behavior of this neoplasia, before resorting to aggressive, costly, and potentially more toxic oncologic therapies, it would seem reasonable to attempt eradication therapy in all patients, irrespective of their H. pylori status.

Tu1084 Long-Term Outcome of Low-Grade Gastric Mucosa-Associated Lymphoid Tissue Lymphoma After Helicobacter pylori Eradication Therapy: A Prospective Single Center Study

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Tu1085 Mantle Cell Lymphoma With Gastrointestinal Involvement: Characteristics and Clinical Outcome

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Tu1086 Management Strategy for Small Duodenal Carcinoid Tumors: Does Conservative Management With Close Follow-up Represent an Alternative to Endoscopic Treatment?

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Synchronous Primary Low-grade Mucosa-associated Lymphoid Tissue Lymphoma of Colon and Stomach

Synchronous Primary Low-grade Mucosa-associated Lymphoid Tissue Lymphoma of Colon and Stomach

SUVmax/THKmax as a Biomarker for Distinguishing Advanced Gastric Carcinoma from Primary Gastric Lymphoma

BackgroundGastric carcinoma and primary gastric lymphoma (PGL) are the two most common malignancies in stomach. The purpose of this study was to screen and validate a biomarker of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for distinguishing advanced gastric carcinoma (AGC) from PGL for clinical applications.Methodology/Principal FindingsWe reviewed PET/CT scans collected from January 2008 to April 2012 of 69 AGC and 38 PGL (14 low-grade mucosa-associated lymphoid tissue [MALT], 24 non-MALT aggressive non-Hodgkin lymphoma [ANHL]) with a focus on FDG intensity (maximum standardized uptake value [SUVmax]) of primary lesions and its CT-detected abnormalities, including maximal gastrointestinal wall thickness (THKmax) and mucosal ulcerations. Gastric FDG uptake was found in 69 (100%) patients with AGC and 36 (95%, 12 MALT vs. 24 ANHL)with PGL. The presence of CT-detected abnormalities of AGC and PGL were 97% (67/69) and 89% (12 MALT vs. 22 ANHL), respectively. After controlling for THKmax, SUVmax was higher with ANHL than AGC (17.10±8.08 vs. 9.65±5.24, p<0.05) and MALT (6.20±3.60, p<0.05). THKmax did not differ among MALT, ANHL and AGC. Mucosal ulceration was more common with AGC (n = 9) than PGL (n = 2),but the difference was not statistically significant (p>0.05). Cross-validation analysis showed that for distinguishing ANHL from AGC, the classifier with SUVmax as a feature achieved a correct classification rate of 81% with thresholds 13.40±1.12 and the classifier with SUVmax/THKmax as a feature achieved a correct classification rate of 83% with thresholds 7.51±0.63.Conclusions/SignificanceSUVmax/THKmax may be as a promising biomarker of FDG-PET/CT for distinguishing ANHL from AGC. Structural CT abnormalities alone may not be reliable but can help with PET assessment of gastric malignancies. 18F-FDG PET/CT have potential for distinguishing AGC from PGL at the individual level.