CT radiomics analysis discriminates pulmonary lesions in patients with pulmonary MALT lymphoma and non-pulmonary MALT lymphoma.

PURPOSE: The aim of this study is to create and validate a radiomics model based on CT scans, enabling the distinction between pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma and other pulmonary lesion causes. METHODS: Patients diagnosed with primary pulmonary MALT lymphoma and lung infections at Fuzhou Pulmonary Hospital were randomly assigned to either a training group or a validation group. Meanwhile, individuals diagnosed with primary pulmonary MALT lymphoma and lung infections at Fujian Provincial Cancer Hospital were chosen as the external test group. We employed ITK-SNAP software for delineating the Region of Interest (ROI) within the images. Subsequently, we extracted radiomics features and convolutional neural networks using PyRadiomics, a component of the Onekey AI software suite. Relevant radiomic features were selected to build an intelligent diagnostic prediction model utilizing CT images, and the model's efficacy was assessed in both the validation group and the external test group. RESULTS: Leveraging radiomics, ten distinct features were carefully chosen for analysis. Subsequently, this study employed the machine learning techniques of Logistic Regression (LR), Support Vector Machine (SVM), and k-Nearest Neighbors (KNN) to construct models using these ten selected radiomics features within the training groups. Among these, SVM exhibited the highest performance, achieving an accuracy of 0.868, 0.870, and 0.90 on the training, validation, and external testing groups, respectively. For LR, the accuracy was 0.837, 0.863, and 0.90 on the training, validation, and external testing groups, respectively. For KNN, the accuracy was 0.884, 0.859, and 0.790 on the training, validation, and external testing groups, respectively. CONCLUSION: We established a noninvasive radiomics model utilizing CT imaging to diagnose pulmonary MALT lymphoma associated with pulmonary lesions. This model presents a promising adjunct tool to enhance diagnostic specificity for pulmonary MALT lymphoma, particularly in populations where pulmonary lesion changes may be attributed to other causes.

Study of individual domains contributing to MALT1 dimerization in BCL10-independent and dependent assembly.

The CARMA-BCL10-MALT1 (CBM) signalosome functions as a pivotal supramolecular module, integrating diverse receptor-induced signaling pathways to regulate BCL10-dependent NF-kB activation in innate and adaptive immunity. Conversely, the API2-MALT1 fusion protein in t(11; 18)(q21; q21) MALT lymphoma constitutively induces BCL10-independent NF-kB activation. MALT1 dimer formation is indispensable for the requisite proteolytic activity and is critical for NF-kB activation regulation in both scenarios. However, the molecular assembly of MALT1 individual domains in CBM activation remains elusive. Here we report the crystal structure of the MALT1 death domain (DD) at a resolution of 2.1 Å, incorporating reconstructed residues in previously disordered loops 1 and 2. Additionally, we observe a conformational regulation element (CRE) regulating stem-helix formation in NLRPs pyrin (PYD) within the MALT1 DD structure. The structure reveals a stem-helix-mediated dimer further corroborated in solution. To elucidate how the BCL10 filament facilitates MALT1 dimerization, we reconstitute a BCL10-CARD-MALT1-DD-IG1-IG2 complex model. We propose a N+7 rule for BCL10-dependent MALT1 dimerization via the IG1-IG2 domain and for MALT1-dependent cleavage in trans. Biochemical data further indicates concentration-dependent dimerization of the MALT1 IG1-IG2 domain, facilitating MALT1 dimerization in BCL10-independent manner. Our findings provide a structural and biochemical foundation for understanding MALT1 dimeric mechanisms, shedding light on potential BCL10-independent MALT1 dimer formation and high-order BCL10-MALT1 assembly.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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 4 years and 7.5 months, and all patients were alive at the last follow-up. CONCLUSION: 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. TRIAL REGISTRATION NUMBER: University Health Network Ethics Committee (CAPCR/UHN REB number 19-5844), retrospectively registered.

The role of baseline 2-[18 F]-FDG-PET/CT metrics and radiomics features in predicting primary gastric lymphoma diagnosis.

Diffuse Large B-Cell Lymphomas (DLCBL) and mucosa-associated lymphoid tissue (MALT) are the two most common primary gastric lymphomas (PGLs), but have strongly different features. DLBCL is more aggressive, is frequently diagnosed at an advanced stage and has a poorer prognosis. The aim of this retrospective study was to explore the role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (2-[18 F]-FDG-PET/CT) and radiomics features (RFs) in predicting the final diagnosis of patients with PGLs. Ninety-one patients with newly diagnosed PGLs who underwent pre-treatment 2-[18 F]-FDG-PET/CT were included. PET images were qualitatively and semi-quantitatively analyzed by deriving maximum standardized uptake value body weight (SUVbw), maximum standardized uptake value lean body mass (SUVlbm), maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), metabolic tumor volume (gMTV) and total lesion glycolysis of gastric lesion (gTLG), total MTV (tMTV), TLG, and first-order RFs (histogram-related and shape related). Receiver-operating characteristic (ROC) curve analyses were performed to determine the differential diagnostic values of PET parameters. The final diagnosis was DLBCL in 54 (59%) cases and MALT in 37 cases (41%). PGLs showed FDG avidity in 83 cases (90%), 54/54 of DLBCL and 29/37 of MALT. All PET/CT metabolic features, such as stage of disease and tumor size, were significantly higher in DLBCL than MALT; while the presence of H. Pylori infection was more common in MALT. At univariate analysis, all PET/CT metrics were significantly higher in DLBCL than MALT lymphomas, while among RFs only Shape volume_vx and Shape sphericity showed a significant difference between the two groups. In conclusion we demonstrated that 2-[18 F]-FDG-PET/CT parameters can potentially discriminate between DLBCL and MALT lymphomas with high accuracy. Among first-order RFs, only Shape volume_vx and Shape sphericity helped in the differential diagnosis.

Artificial intelligence-based differential diagnosis of orbital MALT lymphoma and IgG4 related ophthalmic disease using hematoxylin-eosin images.

PURPOSE: To investigate the possibility of distinguishing between IgG4-related ophthalmic disease (IgG4-ROD) and orbital MALT lymphoma using artificial intelligence (AI) and hematoxylin-eosin (HE) images. METHODS: After identifying a total of 127 patients from whom we were able to procure tissue blocks with IgG4-ROD and orbital MALT lymphoma, we performed histological and molecular genetic analyses, such as gene rearrangement. Subsequently, pathological HE images were collected from these patients followed by the cutting out of 10 different image patches from the HE image of each patient. A total of 970 image patches from the 97 patients were used to construct nine different models of deep learning, and the 300 image patches from the remaining 30 patients were used to evaluate the diagnostic performance of the models. Area under the curve (AUC) and accuracy (ACC) were used for the performance evaluation of the deep learning models. In addition, four ophthalmologists performed the binary classification between IgG4-ROD and orbital MALT lymphoma. RESULTS: EVA, which is a vision-centric foundation model to explore the limits of visual representation, was the best deep learning model among the nine models. The results of EVA were ACC = 73.3% and AUC = 0.807. The ACC of the four ophthalmologists ranged from 40 to 60%. CONCLUSIONS: It was possible to construct an AI software based on deep learning that was able to distinguish between IgG4-ROD and orbital MALT. This AI model may be useful as an initial screening tool to direct further ancillary investigations.

Histopathologic clues to the etiopathogenesis of orbital inflammatory disease: Idiopathic, IgG4-related, neoplastic, autoimmune and beyond.

Orbital inflammatory diseases represent a heterogenous group of idiopathic, autoimmune-related, and sometimes neoplastic conditions with overlapping clinical and histopathologic features, as well as variable levels of IgG4-positive plasma cells detected within tissue biopsies. Some histopathologic features, especially in an appropriate clinical context, may point to a specific diagnosis in a given patient. Diagnoses of non-specific orbital inflammation, orbital inflammation related to autoimmune diseases such as granulomatosis with polyangiitis and IgG4-related disease, lymphoma, and xanthogranulomatous diseases are discussed, contrasted and illustrated.

Thymic MALT lymphoma associated with Sjögren's syndrome with postoperative cardiac tamponade and acute pleuritis: a case report.

BACKGROUND: Thymic mucosa-associated lymphoid tissue (MALT) lymphoma is rare and is known to be associated with Sjögren's syndrome (SjS). SjS is rarely accompanied by serositis. Here, we describe the first case of postoperative cardiac tamponade and acute pleuritis in a patient with thymic MALT lymphoma associated with SjS. CASE PRESENTATION: A 33-year-old woman with SjS presented with an anterior mediastinal mass on chest computed tomography, which was performed for further examination of the condition. Suspecting a thymic MALT lymphoma or thymic epithelial tumor, total thymectomy was performed. The mediastinal mass was histopathologically diagnosed as a thymic MALT lymphoma. The patient was discharged with a good postoperative course but visited the hospital 30 days after surgery for dyspnea. Cardiac tamponade was observed and drainage was performed. Four days after pericardial drainage, chest radiography revealed massive left pleural effusion, and thoracic drainage was performed. The patient was diagnosed with serositis associated with SjS and treated with methylprednisolone, which relieved cardiac tamponade and pleuritis. CONCLUSIONS: Surgical invasion of thymic MALT lymphomas associated with SjS may cause serositis. Postoperative follow-up should be conducted, considering the possibility of cardiac tamponade or acute pleuritis due to serositis as postoperative complications.

A Rare Case of Primary Pulmonary Diffuse Large B-Cell Lymphoma Transformed from Marginal Zone Mucosa-Associated Lymphoid Tissue Lymphoma.

Primary pulmonary lymphoma is a rare neoplasm characterized by the proliferation of lymphoid tissue affecting the lungs. The most common subtype is marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). Rarely, a MALT lymphoma transforms into a diffuse large B-cell lymphoma (DLBCL). Treatment options include chemotherapy, radiotherapy, immunotherapy, and surgery. Here, we describe a patient with a primary pulmonary MALT lymphoma transforming into DLBCL. The purpose of this case report is to raise awareness of the relevant clinical and imaging features and to emphasize the need for a multidisciplinary approach to optimal management. In addition, we screened the PubMed and Embase databases for similar reports with a confirmed presence of transforming lymphoma within the lungs.

A case of endobronchial mucosa-associated lymphoid tissue (MALT) lymphoma successfully treated with radiotherapy and a review of the literature.

A 60-year-old man was noted to have an elevated lesion in the right mainstem bronchus on chest computed tomography (CT) during his annual medical checkup 3 years previously. The lesion had gradually increased in size. FDG-PET showed no accumulation. Bronchoscopy revealed 5 nodular smooth surface protrusions on the ventral surface of the right mainstem bronchus, with the largest lesion that measured 5 mm in diameter. Biopsy showed diffuse infiltration of small lymphocytes, positive for CD20 and subsequently diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma. The lesions disappeared on chest CT after radiotherapy, and no recurrence has been observed after 5 years. We reviewed 48 cases of endobronchial MALT lymphoma in the literature and provided a comprehensive review of the literature to date including our case.

Endoscopic ultrasound-guided fine needle biopsy diagnosis of circumferentially extraluminal mucosa-associated lymphoid tissue lymphoma in the transverse colon: a case report.

A 61-year-old man present to us with continued abdominal pain without abdominal tenderness for 1 month. Blood testing showed elevated biliary enzymes and inflammation. Contrast-enhanced computed tomography (CT) revealed thickening of the transverse colon with relatively strong enhancement but no bile duct dilatation. Colonoscopy revealed localized edema and granular mucosa in the transverse colon. Fluoroscopic endoscopy exhibited the absence of haustra. Multiple biopsies were performed, but differentiation between mild inflammation and mucosa-associated lymphoid tissue (MALT) lymphoma was inconclusive. To establish a definitive diagnosis, transgastric endoscopic ultrasound-guided fine needle biopsy of the hypoechoic mass was performed. Histopathological analysis exhibited the proliferation of small-sized lymphocytes. Fluorescence in situ hybridization revealed the characteristic API2-MALT1 translocation of MALT lymphoma. We performed liver biopsy to investigate biliary enzyme elevation. Histopathology confirmed lymphocytic infiltration within Glisson's capsule. Immunohistochemistry showed positive for CD20 and negative for CD3 and CD5, signifying the infiltration of MALT lymphoma in the liver. Based on these findings, we diagnosed MALT lymphoma, Lugano classification Stage IV. We performed bendamustine-rituximab (BR)-combined therapy. After six courses of BR-combined therapy, colonoscopy revealed improvement in the lead pipe sign and CT revealed disappearance of the mass.

Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma of the Urinary Bladder: A Case Report of a Rare Presentation.

Primary lymphoma of the urinary bladder is extremely rare. We present the case of a 67-year-old woman diagnosed with primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) of the urinary bladder. The patient presented with macroscopic hematuria. Renal ultrasound revealed a solid vascularized mass, in the inferior wall of the bladder. Pelvic computed tomography (CT) and magnetic resonance imaging (MRI) confirmed the presence of a polypoid lesion on the left side of the inferior bladder wall, measuring 40x45 mm, and the MRI study with gadolinium revealed that the entire bladder wall was involved. The patient underwent transurethral resection of the bladder tumor, demonstrating a histologic extensive involvement of bladder tissue by MALT lymphoma. The patient was treated with radiotherapy (24 Gy in 12 fractions) and four cycles of rituximab. She remained without evidence of disease 12 months later.

Revealing the clinical impact of MTOR and ARID2 gene mutations on MALT lymphoma of the alimentary canal using targeted sequencing.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are a group of diseases with marked heterogeneity, including clinical, immunohistochemical, and molecular heterogeneity. The disease remains unspecified in the genetic landscape with only a few sequencing studies to date; however, systematic studies of alimentary canal MALT lymphoma have not been reported. To better understand the genetics of this tumor, targeted sequencing in a group of 31 cases (including 2 esophageal, 2 colonic, 4 small intestinal, and 23 gastric cases) and two cases of lymph node hyperplasiawere performed. We found epigenetic regulation (DNMT3A, KMT2D, KMT2A, EP300, TET2, etc.), signaling pathways (APC, CHD8, TNFAIP3, TNFRSF14, ZAP70, NF1,), and tumor suppressor genes (TP53, BCORL1, FOXO1, ATM, etc.) involved. Moreover, we found MTOR gene mutations in 16% of the cases that made these patients more prone to recurrence and metastasis than those with MTOR wild type genes. More interestingly, ARID2 mutations were detected in 32% of all the cases, and the mutation rate was higher and statistically significant in Helicobacter pylori (Hp)-negative patients in the gastric group. Therefore, this study found that MTOR and ARID2 gene mutations have pathogenic and prognostic implications.

The prognosis of patients with primary pulmonary mucosa-associated lymphoid tissue lymphoma: Treated with surgery or chemotherapy?

OBJECTIVES: The goal of this project was to evaluate the effect of surgical treatment and the long-term survival of patients with staged IE/IIE pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. METHODS: From January 2004 to December 2018, we retrospectively analysed 96 patients diagnosed with low-stage primary pulmonary MALT lymphoma according to the modified Ann Arbor staging system (IE/IIE). We compared the outcomes of different treatment modalities for staged IE/IIE MALT lymphoma. Progression-free survival (PFS) and overall survival were estimated using Kaplan-Meier curves, and the differences were compared using the log-rank test. The Cox proportional hazards model was used in this study. RESULTS: The median PFS time of low-staged MALT lymphomas was 118 months. The overall survival and PFS of the radical surgery group and the biopsy + chemotherapy group suggested no significant difference (P = 0.63, P = 0.65). Patients positive for Blc-2 and Ki-67 suffered from a compromised PFS (P = 0.023, P = 0.006). The Cox adjusted proportional hazards model analysis suggested that surgical procedures were not protective factors for patients with low-staged (IE/IIE) pulmonary MALT lymphoma, whereas being positive for Blc-2 and Ki-67 was a risk factor for patients with low-staged pulmonary MALT lymphoma (hazard ratio: 9.567; P = 0.044; hazard ratio: 6.042, P = 0.049). CONCLUSIONS: Our findings suggested that for staged IE/IIE pulmonary MALT lymphoma, radical surgical resection did not provide a survival benefit compared with chemotherapy after biopsy. Thus, radical surgery may be avoided unless biopsy is necessary for a diagnosis that requires sublobar resection. For those lesions that were Blc-2- or Ki-67-positive, compromised survival may be suggested.

Case report: Incidental MALT lymphoma of the left adrenal gland mimicking a metastatic spread within durvalumab maintenance treatment in inoperable stage III non-small cell lung cancer.

Durvalumab after chemotherapy in non-operable stage III non-small cell lung cancer (NSCLC) is the standard of care worldwide. We present a patient with the incidental discovery of a unilateral MALT lymphoma of the adrenal gland and adrenalitis during durvalumab maintenance treatment detected by 18F-FDG-PET/CT. We assessed the clinical and histopathological findings, radiological examinations and overall treatment. Our work emphasizes the significance of considering other differential diagnoses and the importance of multidisciplinary treatment of the findings, especially within clinical trials.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue of the dura mimicking meningioma: a case report and literature review.

MALT lymphoma of the dura is a very rare type of low-grade B-cell lymphoma. Little more than 100 cases have been reported in the literature to date. We report a 43-year-old woman who was referred to hospital because of a series of three tonic-clonic seizures on the day of admission. Neurological examination revealed confusion and aphasia. Magnetic resonance imaging (MRI) showed a contrast-enhanced, broad-based lesion along the dura in the left parieto-occipital area. The suspicion of an en plaque meningioma was raised. The tumour invaded the brain parenchyma with visible extension into the brain sulci. There was a marked brain oedema surrounding the lesion and causing the midline shift 8 mm to the right. After stabilization of neurological condition (intravenous diuretics and steroids), the operation was performed. The diagnosis of dural MALT lymphoma was established. During the pathological examination, it was especially problematic to distinguish MALT lymphoma from follicular lymphoma, but the final diagnosis was MALT lymphoma. Surgical partial removal with additional R-CVP immunochemotherapy (rituximab, cyclophosphamide, vincristine and prednisone) resulted in complete remission. The follow-up period is 1 year. Our presented case of a MALT lymphoma highlights the fact that surgical partial removal with additional immunochemotherapy is an available option in these rare intracranial tumours.

Molecular Mechanisms and Treatment Strategies for Helicobacter pylori-Induced Gastric Carcinogenesis and Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma.

Helicobacter pylori has been classified as a class I carcinogen by WHO because of its primary involvement in the development of gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. This review focuses on understanding the molecular pathophysiological mechanisms that operate within intracellular transduction pathways and their relevance in the treatment strategies for the two main diseases caused by H. pylori. H. pylori virulence factors such as cytotoxin-associated gene A and vacuolating cytotoxin A genotypes, inflammatory mediators, H. pylori-induced microRNA deregulation, alterations in autophagy proteins and regulators, and changes in DNA methylation are some of the molecular mechanisms that play essential roles in H. pylori infection and gastric carcinogenesis. The discovery of novel treatment strategies that target the deregulated intracellular transduction pathways in gastric carcinogenesis and MALT lymphoma is critical. H. pylori eradication (HPE) is not limited to H. pylori-dependent low-grade MALT lymphoma and may be used in patients with high-grade diffuse large B-cell lymphoma (DLBCL) (de novo or DLBCL-MALT lymphoma). The loss of H. pylori dependency and high-grade transformation appear to be distinct events in the progression of gastric lymphoma. Interestingly, patients with H. pylori-positive gastric DLBCL without histological evidence of MALT lymphoma (pure gastric DLBCL) may respond to HPE therapy.

A rare case of primary breast lymphoma presenting as calcifications on screening mammography.

Extranodal marginal zone lymphoma (EMZL) is a low-grade subtype of B-cell non-Hodgkin lymphoma that can affect any mucosal tissue, most commonly the GI tract. Primary involvement of the breast, known as primary breast lymphoma (PBL), is a very rare manifestation. We report an unusual case of a 65-year-old woman with primary breast EMZL presenting as calcifications discovered during screening mammography. This represents an exceedingly atypical appearance of primary breast lymphoma that is rarely described in the literature.

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.

Simultaneous primary thyroid MALT lymphoma and papillary thyroid cancer.

The mucosa-associated lymphoid tissue (MALT) lymphoma subtype, specifically extranodal marginal zone B-cell lymphoma, is a rare variant. Within this subtype, primary thyroid MALT lymphoma is an uncommon occurrence. The literature provides limited documentation on thyroid MALT lymphomas, as their prevalence is comparatively lower than in other organ sites. The coexistence of papillary thyroid carcinoma (PTC) and thyroid MALT lymphomas is exceedingly rare. It presents a rare case of primary thyroid MALT lymphoma accompanied by PTC, thyroid lymphoma not being considered before surgery. A 64-year-old female patient, who had been experiencing symptoms related to a substantial thyroid tumor for a duration of three years, she refused to do a needle biopsy before surgery and expressed a preference for surgical resection. Consequently, the patient underwent a total thyroidectomy along with lymphadenectomy of the central compartment. A histological examination subsequently confirmed the presence of papillary thyroid carcinoma (PTC) and mucosa-associated lymphoid tissue (MALT) lymphoma. Due to the favorable response of the MALT lymphoma to local treatment and the absence of metastasis in other organs, no further treatment was administered for the MALT lymphoma following the surgery. Currently, the patient exhibits no signs of tumor recurrence based on ultrasound and laboratory evaluations. We also provide an overview of the clinical findings on PTC and MALT lymphoma patients already reported and discuss the possible treatment strategy.

The National Landscapes of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: Stable Trends in Black Populations and Late-Stage Tumors.

BACKGROUND: Helicobacter pylori (H. Pylori) eradication has been the mainstream for preventing and treating gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Prior data showed disparities in eradication rates of H. Pylori between different populations. This can potentially impact the occurrence of gastric MALT lymphoma. There are limited data on the incidence and mortality rates and trends of gastric MALT lymphoma in the US. Therefore, the aim of the current study was to conduct a time-trend analysis of gastric MALT lymphoma incidence and mortality rates in different populations. METHODS: The incidence rates of gastric MALT lymphoma were calculated from the United States Cancer Statistics (USCS) database (which covers nearly 98% of the US population) between 2001-2020 and were age-adjusted to the standard 2000 US population using SEER*Stat software (version 8.4.3, national cancer institute "NCI"). Incidence-based mortality (IBM) rates, also age-adjusted to the standard 2000 US population, were calculated from the Surveillance Epidemiology and End Results (SEER) database. Tumor location was specified using ICD-O-3 codes C 160-C 169 with malignant behavior. Histopathology was specified using the ICD-O-3 code 9699. The rates were categorized by sex, age, race/ethnicity, and tumor stage at diagnosis. Age groups were older adults (aged 55 years or older) and younger adults (aged younger than 55 years). Race/ethnic groups included Non-Hispanic White (White), Non-Hispanic Black (Black), Hispanic, Non-Hispanic Asian/Pacific Islander (API), and Non-Hispanic American Indian/Alaska Native (AI/AN), as reported in the database. Stage at diagnosis included early stage (in situ and localized tumors) and late stage (regional and distant site tumors). Joinpoint Regression Software (version 5.0.2, NCI) using the weighted Bayesian Information Criteria method was used to generate time trends. Trends were reported as annual percentage change (APC) and average APC (AAPC). Parametric estimations were used with a two-sided t-test to evaluate the trends with a p-value cutoff at 0.05. RESULTS: There were 21,625 patients diagnosed with gastric MALT lymphoma in the US between 2001 and 2020. Overall, incidence rates were significantly decreasing over the study period (AAPC = -1.93). This decrease was seen in males (AAPC = -1.67) and in females (AAPC = -1.66) (Figure). When categorized by age groups, older adults also experienced a significant decrease in gastric MALT lymphoma incidence rates (AAPC = -1.66). While this was also seen in younger adults, the rates were decreasing at a slower pace (AAPC = -1.38). When categorizing the trends by race/ethnicity, incidence rates were significantly decreasing in White (AAPC = -2.09), Hispanic (AAPC = -1.61), and API (AAPC = -3.92) populations. However, the rates were stable among Blacks. While early-stage tumors experienced a significant decrease (AAPC = -1.10), the rates were stable for late-stage tumors. When evaluating mortality, there were 11,036 patients whose death was attributed to gastric MALT lymphoma between 2000 and 2020. IBM rates were decreasing in males (AAPC = -1.47), older adults (AAPC = -1.55), Whites (AAPC = -1.23), Hispanics (AAPC = -1.73), APIs (AAPC = -2.30), and early-stage tumors (AAPC = -1.08). On the other hand, IBM rates were stable in females, younger adults, Blacks, and late-stage tumors. DISCUSSION: An extensive nationwide data analysis encompassing nearly 98% of patients diagnosed with gastric MALT lymphoma in the US unveils a declining trend in the incidence of cancer overall over the past two decades. This decline is observed in both sexes and various age groups. When stratifying by race and ethnicity, this incidence has been decreasing in all populations except among Black individuals. While early-stage tumors have also demonstrated a significant decrease in incidence rates, late-stage tumors have shown no parallel decline. Mortality evaluation also revealed an improvement in most of the US population except among females, younger adults, Black individuals, and late-stage tumors. While the cause of our findings is unclear, it could be driven by disproportionate exposure to risk factors, including H. Pylori, and disparities in screening, management, and outcomes. Future studies are warranted to investigate factors contributing to worse outcomes of gastric MALT lymphoma, especially in the Black population.