Case Of Mucosa-associated Lymphoid Tissue Lymphoma Research Articles

Mucosa-Associated Lymphoid Tissue Lymphoma as a Rare Mimicker of Relapsing Polychondritis.

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade B cell extranodal lymphoma characterized by clonal marginal zone lymphocyte proliferation. We report a case of MALT lymphoma with a relapsing polychondritis (RP)-like phenotype, manifesting as rapidly progressive tracheal stenosis requiring tracheotomy.

Proportion and characteristics of Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: A systematic review and meta-analysis.

While Helicobacter pylori (H. pylori) infection is common in patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, there are still individuals who test negative for it. The proportion and characteristics of these patients remain unclear. We conducted a systematic search of the PubMed, Embase, and Cochrane Library databases for relevant articles. Using a random effects model, we performed a meta-analysis to assess the pooled proportion of gastric MALT lymphoma patients with negative H. pylori tests. Additionally, we compared characteristics between gastric MALT lymphoma patients with and without H. pylori infection to examine clinical features in H. pylori-negative cases. A total of 50 studies involving 6033 patients were included. The overall proportion of gastric MALT lymphoma patients with negative H. pylori tests was 20.5% (95% confidence interval: 17.0%-24.6%). This rate exhibited an increasing trend over the years, particularly in non-Asian countries and in studies published after 2013, as well as in cases with sample sizes exceeding 100 participants, in male individuals, and among those with proximal or multiple lesions, non-superficial type morphology, submucosal invasion, and advanced clinical staging. Compared to H. pylori-positive patients, those who tested negative were more likely to be male, have proximal lesions, exhibit submucosal invasion, and present with an advanced clinical stage. This study provides comprehensive information on the proportion and characteristics of H. pylori-negative gastric MALT lymphoma cases, highlighting the need for future clinical attention to treatment and surveillance in this patient population.

Mucosa-associated lymphoid tissue lymphoma of the lacrimal gland: A case report and literature review.

The most common subtype of primary lymphoma of the ocular adnexa is the mucosa-associated lymphoid tissue (MALT) subtype. MALT lymphoma of the lacrimal gland is relatively rare among the lacrimal gland tumors, and the early clinical symptoms are atypical, which can easily lead to misdiagnosis and missed diagnosis. Here, we report a case of MALT lymphoma of the lacrimal gland and explore its clinical manifestations, pathological characteristics, management, and pathogenesis, with the aim of helping clinicians gain an in-depth understanding of ocular adnexal MALT lymphoma. A 60-year-old man presented to our hospital with proptosis and diplopia. The right eye deviated and shifted toward the lower part of the nose. Orbital enhanced magnetic resonance imaging suggested a mass with a maximum cross-section of 3.2 × 2.1 cm. T1 weighted image was isointense, and the enhancement was more uniform and obvious. The right orbital mass was treated surgically, and the final pathology report was MALT lymphoma. After the pathological report was released, the patient was transferred to the hematology department for further diagnosis and no further treatment was given eventually. Seven months later, the patient did not complain of discomfort. Whole-body positron emission tomography-computed tomography, superficial lymph node examination and orbital magnetic resonance imaging revealed no abnormal changes. The clinical manifestations of MALT lymphoma are heterogeneous. Imaging examination is important for assessing the size of the tumor and its relationship with adjacent tissues. Postoperative pathological examination may provide further evidence for the evaluation of the patient's surgical efficacy and prognosis. Management of MALT lymphoma of the lacrimal gland requires a multidisciplinary approach involving ophthalmologists, hematologists, and radiotherapists.

Massive bleeding in small intestinal mucosa-associated lymphoid tissue lymphoma associated with COVID-19 infection: a case report

Abstract The increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma is closely associated with chronic antigenic stimulation, with infection being the most common cause of recurrence. Lesions are usually associated with the gastrointestinal tract, and the involvement of small intestinal is rare. Recent studies have established a close relationship between novel coronavirus 2019 (COVID-19) and the occurrence and progression of various diseases. This article presents a rare case of a small intestinal MALT lymphoma. The patient was initially admitted with COVID-19 pneumonia and subsequently developed gastrointestinal bleeding during hospitalization. Medical and endoscopic treatments were ineffective, and an emergency exploratory laparotomy was performed. The affected segment of the small intestine was excised, and a pathological biopsy confirmed the diagnosis of MALT lymphoma. This case underscores the significance of raising clinical awareness of this condition among health care professionals.

Primary MALT lymphoma of the breast: pathological and radiological characteristics.

Primary Mucosa-associated lymphoid tissue (MALT) lymphoma is a rare diagnosis in the breast, and clinical diagnosis based on radiological features is often challenging. This study aimed to evaluate the clinicopathological, and radiological characteristics of the patients diagnosed with primary breast MALT lymphoma. This study examined 18 cases of primary MALT lymphoma of the breast diagnosed at a single tertiary center between January 2002 to December 2020. Medical charts, radiological imaging and original pathology slides were reviewed for each case. All cases were female (gender assigned at birth) and presented with a palpable mass or an incidental imaging finding. Imaging presentation ranged from mammographic asymmetries, circumscribed masses, and ultrasound masses lacking suspicious features. Seventeen cases were biopsied under ultrasound; one received a diagnostic excision biopsy. Microscopic examination of the breast specimens demonstrated atypical small lymphocyte infiltration with plasmacytoid differentiation and rare lymphoepithelial lesions. Immunohistochemistry was performed in all cases and established the diagnosis. Most patients were treated with radiotherapy, and only three were treated with chemotherapy. The median follow-up period was 4years and 7.5months, and all patients were alive at the last follow-up. Primary MALT breast lymphomas are usually indolent and non-systemic, and local radiotherapy may effectively alleviate local symptoms. Radiological findings show overlap with benign morphological features, which can delay the diagnosis of this unusual etiology. Although further studies involving a larger cohort could help establish the clinical and radiological characteristics of primary breast MALT lymphomas, pathology remains the primary method of diagnosis. University Health Network Ethics Committee (CAPCR/UHN REB number 19-5844), retrospectively registered.

Extranodal Marginal Zone Lymphoma of Mucosa Associated Lymphoid Tissue (MALT LYMPHOMA) With Extensive Plasma Cell Differentiation and Localized Amyloid Deposition.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma is a mature and clinically indolent B cell lymphoma composed of heterogeneous cell population. Plasma cell differentiation is commonly seen in MALT lymphomas. However, plasmacytic differentiation along with localized amyloid deposition in the lungs is an extremely rare. We encountered a unique case of Extranodal MALT lymphoma with extensive plasmacytic differentiation and amyloid deposition. A 78-year-old female with past history of Gastric MALT lymphoma, status post chemotherapy presented in outpatient clinic. PET scan revealed an incidental 9 mm nodule in left lung, and subsequently underwent biopsy. Histology showed sheets of heterogeneous neoplastic cells including small lymphocytes, monocytoid cells, and abundant number of plasma cells (Fig A) in the background of hyalinization (Fig B). Immunohistochemical (IHC) reveals lymphoma cells are positive for CD20 (Fig C) and CD43, and plasma cells showed lambda restriction (Fig D). Furthermore, Congo Red stain of eosinophilic background showed positive birefringence upon polarization, consistent with Amyloid. Great caution is required in differentiating these cases from lymphoplasmacytic lymphoma as the histologic and IHC features can significantly overlap, and studies have also suggested that plasmacytic differentiation in these cases represent precursor neoplasm of plasma cells. Amyloid depositions in MALT lymphomas are rare and organ confined but can lead to local complications and cause considerable morbidity. Therefore, it is necessary to be aware of the association between MALT lymphoma with extensive plasma cell differentiation and amyloid deposition, as close clinical follow up is recommended.

Stromal area differences with epithelial-mesenchymal transition gene changes in conjunctival and orbital mucosa-associated lymphoid tissue lymphoma.

To examine the molecular biological differences between conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma and orbital MALT lymphoma in ocular adnexa lymphoma. Observational case series. A total of 129 consecutive, randomized cases of ocular adnexa MALT lymphoma diagnosed histopathologically between 2008 and 2020.Total RNA was extracted from formalin-fixed paraffin-embedded tissue from ocular adnexa MALT lymphoma, and RNA-sequencing was performed. Orbital MALT lymphoma gene expression was compared with that of conjunctival MALT lymphoma. Gene set (GS) analysis detecting for gene set cluster was performed in RNA-sequence. Related proteins were further examined by immunohistochemical staining. In addition, artificial segmentation image used to count stromal area in HE images. GS analysis showed differences in expression in 29 GS types in primary orbital MALT lymphoma (N=5,5, FDR q-value <0.25). The GS with the greatest difference in expression was the GS of epithelial-mesenchymal transition (EMT). Based on this GS change, immunohistochemical staining was added using E-cadherin as an epithelial marker and vimentin as a mesenchymal marker for EMT. There was significant staining of vimentin in orbital lymphoma (P<0.01, N=129) and of E-cadherin in conjunctival lesions (P=0.023, N=129). Vimentin staining correlated with Ann Arbor staging (1 versus >1) independent of age and sex on multivariate analysis (P=0.004). Stroma area in tumor were significant difference(P<0.01). GS changes including EMT and stromal area in tumor were used to demonstrate the molecular biological differences between conjunctival MALT lymphoma and orbital MALT lymphoma in ocular adnexa lymphomas.

Usefulness and Limitations of Current Diagnostic Strategies for Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma: Lessons Learned From a Large Cohort.

The pathologic diagnosis of pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is challenging. To evaluate the diagnostic usefulness and limitations of current diagnostic strategies for pulmonary MALT lymphoma. A retrospective review of 120 cases of pulmonary MALT lymphoma from 2014 through 2021 was performed. Clinicoradiologic presentations overlapped with previous observations in patients with MALT lymphoma, such as a wide age range, female predominance, frequent association with autoimmune disease or immunodeficiency, and broad imaging findings. The histopathologic diagnosis was based on a combination of morphology, immunohistochemistry, and demonstration of B-cell lineage clonality. Two-thirds (76 of 113) of MALT lymphomas had lymphoplasmacytoid cytomorphology. Occasionally, MALT lymphomas were associated with granulomas/giant cells (29%, 35 of 120) or immunoglobulin deposition disease (21%, 25 of 120), including light chain/heavy chain deposition disease, amyloidosis, and/or crystal storing histiocytosis. While CD5, CD10, Bcl-2, and Bcl-6 rarely revealed aberrancies, aberrant CD43 expression either on B-cells or on plasma cells was detected in 42% (27 of 64) of cases, including cases for which proof of clonality could not be obtained. κ/λ in situ hybridization was particularly useful for tumors with lymphoplasmacytoid morphology but performed poorly in lymphomas having no plasmacytic differentiation. κ/λ immunohistochemistry showed no additional usefulness when applied together with κ/λ in situ hybridization. Immunoglobulin gene rearrangement studies by polymerase chain reaction achieved high detection rates of clonality in all cytomorphologic subgroups. Our study offers a practical evaluation of common diagnostic tests in pulmonary MALT lymphoma. We offer recommendations for a diagnostic workup that takes into consideration the usefulness and the specific limitations of the various diagnostic strategies.

Helicobacter pylori-negative mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: A clinicopathologic analysis.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is historically associated with Helicobacter pylori (HP) infections in more than 80% of patients. However, the incidence of HP-negative MALT lymphoma has been increasing. The clinicopathologic features have not been well studied, and optimal management strategies remain unclear. The pathology database was searched for primary gastric MALT lymphomas diagnosed from 2000 to 2017. The clinical data and the slides were reviewed. The cases were divided for analysis into those with a background of chronic gastritis with HP, chronic gastritis without HP, and without either a background of chronic gastritis or HP. Of 70 gastric MALT lymphoma cases identified, 26 (37% of total) had chronic gastritis and were positive for HP histologically (n = 23) or were HP positive by additional laboratory testing (n = 3). The remaining 44 (63% of total) cases were HP negative by histology. Within the HP-negative cases, 5 (11% of HP-negative cases) showed histologic gastritis while 39 (89% of HP-negative cases) did not have sufficient evidence of gastritis through review of slides (n = 18) or based on available pathology reports (n = 21). The HP-negative cases without gastritis had higher propensities to show a mass lesion on endoscopy compared with HP-positive cases (37.5% vs 11.1%, P = .02) at the initial diagnosis. The immunophenotype and rate of positive B-cell gene rearrangement were not significantly different between the 2 groups. While all HP-positive patients received antibiotics for HP eradication, treatment in the HP-negative group varied among antibiotics, radiation, rituximab, or chemotherapy. Among HP-negative patients with available follow-up, 13 (39%) showed disease recurrence, similar to the recurrence rate in HP-positive patients; however, no individual from either group has died of the disease thus far. The incidence of HP-negative MALT lymphoma is increasing, and in our practice, it is currently more common than HP-associated MALT lymphomas. The pathophysiology of HP-negative MALT lymphoma without chronic gastritis remains unclear. Follow-up data in our study suggest that the prognosis of these cases is excellent despite varied management modalities.

Gastric Mucosa-associated Lymphoid Tissue Lymphoma Mimicking Signet Ring Cell Carcinoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type of extranodal non-Hodgkin lymphoma. Endoscopic findings are nonspecific and variable; therefore, differentiation of this malignancy from early gastric cancer is challenging during endoscopy. Although an endoscopic biopsy is the gold standard for diagnosis, a biopsy may not conclusively establish the diagnosis in all cases. Diagnostic confirmation requires interpretation of the biopsy specimen findings by an experienced histopathologist, and an additional immunoglobulin heavy chain (IgH) rearrangement test may aid with accurate diagnosis. We present a case of gastric MALT lymphoma that histopathologically mimicked signet ring cell carcinoma (SRCC) on evaluation of repeat endoscopic biopsies. Following endoscopic submucosal dissection (ESD), we confirmed the final diagnosis of gastric MALT lymphoma based on histopathological findings of prominent lymphoid infiltrates accompanied by lymphoepithelial lesions and results of the monoclonal IgH rearrangement test. Notably, a few carcinoma-like signet ring cells (SRCs) in the specimen were attributed to a reactive change. Clinicians should be mindful of possible SRCs in gastric MALT lymphoma specimens to avoid misdiagnosis of SRCC in patients with gastric MALT lymphoma. Confirmatory ESD may be useful for accurate diagnosis and appropriate management of such lesions.

Primary rectal mucosa-associated lymphoid tissue lymphoma treated with only endoscopic submucosal dissection: A case report

Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct subtype of non-Hodgkin B cell lymphoma that mostly involves the gastrointestinal tract. The stomach is the most commonly affected site whereas colorectal involvement occurs very rarely. Given its rarity, the management and clinical outcome of colorectal MALT lymphoma are not well established yet. From the superficial capillary bed in the lower rectum. Endoscopic ultrasonography showed homogenous hypoechoic lesions in the deep mucosal layer. Endoscopic submucosal dissection (ESD) was done for accurate histologic diagnosis and treatment and both the rectal lesions were completely removed en bloc and subsequently diagnosed as primary rectal MALT lymphoma. Herein, we report a case of primary rectal MALT lymphoma in a 68-year-old woman that was treated by only ESD, and the 12-month follow-up revealed no tumour recurrence. These results of our case and previous reports suggest that endoscopic resection alone may be a feasible and safe treatment for primary colorectal MALT lymphoma and allows organ preservation.

Perplexity of Preoperative Multimodal Investigations in a Case of Parotid MALToma.

Mucosa-associated lymphoid tissue(MALT) lymphoma is a distinct subtype of lymphoma, presenting as a diffuse gland involvement or a discrete mass. Pre-operative diagnosis is a challenge as Fine Needle Aspiration Cytology is often inconclusive and presently no radiological investigation is confirmatory, therefore final diagnosis is made after surgical resection and immunohistopathology. We report a case of MALT lymphoma, which clinically presented as a unilateral large diffuse swelling of the parotid gland with a diagnostic dilemma eventually underwent total parotidectomy to be finally diagnosed as MALT lymphoma of parotid gland and received field radiotherapy with complete cure and no recurrence in a 2-year follow-up.

Low-grade malt lymphoma of the nasopharynx in young adults: Successful treatment of a rare diagnosis at a rare site by radiotherapy.

Mucosa Associated Lymphoid Tissue (MALT) lymphoma is the third most common subgroup of Non-Hodgkin's lymphoma and is the most common type of primary extranodal lymphoma. They are rarely found in the nasopharyngeal region and their mean age at presentation is the sixth decade of life. We present the clinical, pathological, treatment and 5-year follow-up data of 5 cases of nasopharyngeal MALT lymphoma treated with definitive radiotherapy at our hospital, between 2009 and 2011. The average age of diagnosis was 27 years which is more than a decade earlier than what has been reported previously. Clinical symptoms included nasal obstruction, tinnitus and hearing loss. All five patients had locoregional disease. They were treated by definitive radiotherapy to a dose between 30 to 40 Gy. At 5 years of follow-up, 4 patients were in complete remission while one had disease relapse. The younger age of presentation compared to older reports in this rare subsite was an interesting finding in our study. The authors speculate that rising levels of particulate air pollution may have played a part in the etiology in this younger population. Our series shows that despite the younger age, the disease displays an indolent course and responds well to radiotherapy alone as the primary treatment. Recurrence or disseminated disease is also highly treatable with systemic chemotherapy.

Clinicopathological analysis of primary thyroid non-Hodgkin lymphoma: a single-center study.

Primary thyroid lymphoma (PTL) is very rare. The aim of this study was to describe the clinical characteristics, pathological features, and survival outcomes of primary thyroid non-Hodgkin lymphoma, including the diagnostic value of clonal immunoglobulin (Ig) gene rearrangements in diagnosing mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland with co-existing Hashimoto thyroiditis (HT). Paraffin-embedded tissues of patients diagnosed in our institute with PTL between 2007 and 2021 were collected. Clinicopathological features and follow-up data were retrospectively analyzed. Analysis of clonal Ig gene rearrangements were performed in patients with suspected PTL. Of the 22 patients included in our study, 17 were female. The median age at diagnosis was 65.5 years (range, 44-80 years). We detected 11 cases of diffuse large B-cell lymphoma (DLBCL), 10 cases of MALT lymphoma, and 1 case of T-cell lymphoma. A total of 18 patients (81.8%) had early stage (I/II) disease. B-cell lymphoma showed diffuse positivity for CD20 but negative markers for thyroid-origin cells. Double-hit and triple-hit lymphomas were not found in the 8 DLBCL cases, and 2 cases of HT with lymphoid tissue dysplasia were diagnosed with MALT lymphoma with gene rearrangement testing. The median follow-up time was 47 months (range, 4-160 months), and the overall survival was 80% for MALT lymphoma (8 of 10), 72.7% for DLBCL lymphoma (8 of 11), and 100% for T-cell lymphoma (1 of 1). There was no significant difference between the groups. PTL mostly affects middle-aged and older adult females with HT, and its main histological type is non-Hodgkin B-cell lymphoma. For patients with HT along with a histologically benign lymphoepithelial lesion, the identification of clonal Ig gene rearrangements is important for differential diagnosis. The prognosis between DLBCL and MALT is not statistically significant.

Primary hepatic extranodal marginal zone B-cell mucosa-associated lymphoid tissue lymphoma treated by laparoscopic partial hepatectomy: a case report

BackgroundPrimary hepatic extranodal marginal zone B-cell mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, so it is difficult to diagnose preoperatively. And there is no established treatment for hepatic MALT lymphoma. We report herein a case of primary hepatic MALT lymphoma treated by laparoscopic partial hepatectomy, and discuss the usefulness of laparoscopic hepatectomy for a rare liver tumor.Case presentationThis patient was a woman in her 60s, who was diagnosed preoperatively as having synchronous liver metastasis from sigmoid colon cancer; therefore, laparoscopic partial hepatectomy was performed. She had a good course after the operation and was discharged on postoperative day 12. However, she was diagnosed pathologically as having primary hepatic MALT lymphoma. A bone marrow biopsy was also performed, and then she was finally diagnosed as having limited-stage primary hepatic MALT lymphoma. She received no postoperative treatment and showed no recurrence for 4 years postoperatively.ConclusionsWe experienced the good result of the patient with limited-stage primary MALT lymphoma treated by laparoscopic partial hepatectomy. Liver tumors are sometimes misdiagnosed by imaging examinations alone. Laparoscopic hepatectomy has been widespread recently as a minimally invasive procedure, and it may be useful for both diagnosis and treatment.

S3738 Agent Orange as a Possible Cause of Helicobacter pylori Negative Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Introduction: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma was first described in 1983 as the most common extranodal site of non-Hodgkin lymphoma. Helicobacter pylori (H. pylori) infection is implicated in 90% of all gastric MALT lymphoma cases. Agent Orange (AO), with traces of oncogenic 2,3,7,8-tetrachlorodibenzo-p-dioxin, has also been classified as a causative agent in non-Hodgkin lymphoma, which includes gastric MALT lymphoma. Here we report a case of H. pylori negative gastric MALT lymphoma in a patient with history of significant AO exposure. Case Description/Methods: A 75-year-old Caucasian male veteran who served in the Vietnam War with significant AO exposure, as well as history of chronic gastroesophageal reflux disease, was referred for endoscopy to evaluate a reported history of un-staged Barrett’s esophagus 5-years prior but with two subsequent normal endoscopies at an outside facility. He noted symptoms of burning chest pain and dyspepsia following large meals, all of which were worsened with spicy foods and improved with omeprazole. Family history was negative for a history of gastric cancer, and he had a 25-pack year smoking history but quit 20 years prior to presentation.Initial esophagogastroduodenoscopy (EGD) revealed abnormal folds in the gastric fundus and erythema in the gastric antrum, but otherwise normal exam including normal duodenum and esophagus. Random gastric biopsies and biopsies of the abnormal folds were consistent with gastric MALT lymphoma, negative for H. pylori and t(11;18)(q21;q21). Repeat EGD 1 month later for further sampling demonstrated identical findings (Figure 1A). Stool testing for H. pylori antigen was also negative. The patient was referred to oncology and after staging imaging was found to have stage IE gastric MALT lymphoma. He was treated with involved site radiation therapy and EGD 3 months later showed both endoscopic and pathologic resolution (Figure 1B). Discussion: The 10% of cases of H. pylori negative gastric MALT lymphoma have an unclear etiology, although dysregulation of nuclear factor-kappa B (NF-κB) principally via translocations t(11;18)(q21;q21) is thought to be a potentially causative genetic alteration. In this patient, neither H. pylori nor the common t(11,18) genetic alteration were present. Given AO is implicated in non-Hodgkin lymphoma and the most common site of extranodal non-Hodgkin lymphoma is the gastric mucosa, AO exposure should be considered a risk factor for development of gastric MALT lymphoma.Figure 1.: (A) EGD demonstrating abnormal gastric mucosa with prominent gastric fundus folds seen on retroflexion during EGD prior to ISRT (radiation) therapy. (B) Post-radiation EGD demonstrating resolution of the abnormalities seen with the pre-treatment EGD including disappearance of the prominent gastric fundus folds.

Endoscopic submucosal dissection for protruding Helicobacter pylori-negative mucosa-associated lymphoid tissue lymphoma of the stomach: a case report

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas have various endoscopic appearances. We report a case of Helicobacter pylori-negative gastric MALT lymphoma with a protruding morphology similar to that of submucosal tumors. A 51-year-old man with a protruding tumor in the gastric cardia was referred to our hospital. Biopsy specimens showed no malignant epithelial tumors or lymphoid hyperplasia. Endoscopic submucosal dissection was performed and the patient was diagnosed with gastric MALT lymphoma. Lymphoma cells were present in the lamina propria mucosae and the submucosa under the non-atrophic fundic gland mucosa, with a feature of homogenous and monotonous growths, which was speculated to have resulted in a protruding morphology similar to that of submucosal tumors. Endoscopic submucosal dissection can be an alternative diagnostic option for gastric MALT lymphoma when the initial pathological diagnosis based on biopsy specimens is difficult.

PULMONARY MALT LYMPHOMA PRESENTING WITH EXTENSIVE CYSTIC LUNG DISEASE

TYPE: Case Report TOPIC: Signs and Symptoms of Chest Diseases INTRODUCTION: MALT (mucosa-associated lymphoid tissue) lymphoma is type of marginal zone non-Hodgkin lymphoma of B-cell origin that can rarely involve the lungs. We hereby present a case of pulmonary MALT lymphoma in a patient with Sjögren’s syndrome that presented with extensive cystic lung changes that was initially confused with lymphangioleiomyomatosis (LAM). CASE PRESENTATION: A 44-year-old former smoker female presented with worsening dyspnea on exertion and dry eyes and mouth. Chest CT had previously demonstrated numerous thin-walled cysts that had been present for several years. Due to worsening dyspnea and pulmonary cystic disease (image 1), she underwent a non-diagnostic VATS lung biopsy 3 years prior to consultation due to concern for LAM. Past medical history was notable for rheumatoid arthritis treated with adalimumab and leflunomide. Laboratory evaluation showed markedly elevated SSA and SSB antibody titers, which along with keratoconjuctivitis sicca and xerostomia was consistent with the diagnosis of Sjögren’s syndrome. The VATS lung biopsy was re-reviewed and showed atypical lymphoplasmacytic infiltrates with kappa light chain deposition, consistent with MALT lymphoma. Esophagogastroduodenoscopy and bone marrow biopsy were negative and staging PET-CT scan revealed no evidence of extrathoracic lymphoma. She was treated with weekly rituximab for 4 doses. DISCUSSION: Pulmonary MALT lymphoma is a rare disorder associated with autoimmune disorders, such as Sjögren’s syndrome. Extensive bilateral cysts are rare. Prognosis is typically good, although progression into high-grade B-cell lymphoma may occur. Treatment depends on symptoms and extent of disease. CONCLUSIONS: Pulmonary MALT lymphoma should be on the differential in patients presenting with bilateral extensive cystic disease. Image1: DISCLOSURE: Nothing to declare. KEYWORD: MALT Lymphoma

A Case of Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma in Buccal Mucosa

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a lowgrade B-cell lymphoma that typically follows an indolent clinical course. It occurs in a variety of mucosal linings extranodal tissue, most commonly in the stomach. Other commonly involved sites include other parts of the gastrointestinal tract, thyroid, salivary gland, lung, lacrimal gland, synovium, dura mater, breast, skin, and eyes. It occurs very rarely in the buccal mucosa. A 50-year-old man came to the clinic while presenting a 5-month history of rightsided buccal mass. The incisional biopsy did not confirm the diagnosis of the lesion. He underwent complete excision of buccal mass for the diagnosis and treatment. The final pathology confirmed MALT lymphoma immunohistochemically. After surgery, he received radiotherapy with 30.6 Gy. There is no recurrence for 8 months after treatment. Herein we report a rare case of buccal MALT lymphoma with a review of the literature.

A novel prognostic nomogram for patients with extragastric mucosa-associated lymphoid tissue lymphoma: Amulticenter study.

BackgroundThe aim of this study was to explore predictors and construct a nomogram for risk stratification in primary extragastric mucosa‐associated lymphoid tissue (MALT) lymphoma.MethodsExtragastric MALT lymphoma cases newly diagnosed between November 2010 and April 2020 were assessed to construct a progression‐free survival (PFS)‐related nomogram. We also performed external validation of the nomogram in an independent cohort.ResultsWe performed multivariate analyses of 174 patients from 3 hospitals who were included in the training cohort. Stage, hepatitis B virus surface antigen (HBsAg) status, and Ki67 expression were significantly associated with PFS. These three factors were used to construct a nomogram, which was shown to have a C‐index of 0.89. Two risk groups (low risk and high risk) were identified by the prognostic model. The 5‐year PFS was 98.9% for the low‐risk group and 69.3% for the high‐risk group (p < 0.001). The overall survival (OS) could also be effectively distinguished by the nomogram, resulting in an OS of 100% for the low‐risk group and 94.6% for the high‐risk group (p = 0.01). These results were validated and confirmed in an independent cohort with 165 patients from another three hospitals. The 5‐year PFS rates were 94.8% and 66.7% for the low‐risk and high‐risk groups, respectively (p < 0.001). The 5‐year OS rates were 97.9% and 88.4%, respectively (p = 0.016).ConclusionThe nomogram could well distinguish the prognosis of low‐ and high‐risk patients with extragastric MALT lymphoma and is thus recommended for clinical use.