Mucosa-associated Lymphoid Tissue Lymphoma Research Articles

Non-Urothelial Malignancy in Urine Cytology

Non-urothelial malignancies of the urinary bladder are relatively rare and can be classified into primary and secondary malignancies. The histological subtypes of non-urothelial malignancy include non-urothelial carcinoma, sarcoma, lymphoma, and melanoma. The common types of primary non-urothelial carcinoma are pure squamous cell carcinoma, adenocarcinoma, and small cell carcinoma. Most primary sarcomas of the urinary bladder are leiomyosarcoma and rhabdomyosarcoma. Extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue origin and diffuse large B-cell lymphoma (DLBCL) are the common primary lymphomas of the urinary bladder. Most secondary tumors of the urinary bladder result from the direct extension of adjacent organs such as the colon/rectum, prostate, and cervix. Hematogenous metastasis from other primary cancers such as breast, stomach, lung, and skin (melanoma) are less common. The cytologic diagnosis of non-urothelial malignancies is challenging due to the significant cytomorphologic overlap with high-grade urothelial carcinoma, its divergent differentiation, and subtypes. Awareness of these diagnostic entities is helpful for accurate diagnosis, especially when encountering urine specimens with unusual cytomorphology.

A Case of Synchronous Primary Gastric and Duodenal Mucosa-Associated Lymphoid Tissue Lymphoma in Remission after Helicobacter pylori Eradication

A Case of Synchronous Primary Gastric and Duodenal Mucosa-Associated Lymphoid Tissue Lymphoma in Remission after <i>Helicobacter pylori</i> Eradication

P107 Real world clinical outcomes of patients with moderate-to-severe rheumatoid arthritis initiating upadacitinib in the United Kingdom: Interim analysis from a prospective observational cohort study (ENDEAVOUR)

Abstract Background/Aims Upadacitinib (UPA) 15 mg, a once-daily Janus kinase inhibitor (JAKi), is approved by NICE for treating adults with moderate-to-severe rheumatoid arthritis (RA) unresponsive to conventional Disease Modifying Antirheumatic Drugs (DMARDs). This study aims to evaluate UPA's real-world effectiveness in the UK. Methods ENDEAVOUR is a prospective observational cohort study which recruited 97 patients with moderate to severe RA whom the managing health care professional has decided to treat with UPA in line with marketing authorisation across 14 sites in the UK. Patient demographics, comorbidities, concomitant therapies and patient reported disease activity were collected at baseline, three months, and six months. Patient Reported Outcomes (PROs) were collected using an app hosted by UMotif. Primary objective was the proportion of patients achieving clinical remission (defined as DAS28&amp;lt;2.6) with upadacitinib at six months. The study is ongoing and therefore not all patients have completed study visits at three and six months yet however this interim analysis reports the baseline demographics of 77 patients whose data has been cleaned thus far and clinical outcomes and safety of UPA 47 adult patients at three months. Data are as observed. Results Data were available for 77 adults at baseline: 42% had moderate and 58% had severe RA based on DAS28-CRP scores. Patients' average age was 55 years, 64 (83%) were female, and most had at least one comorbidity, such as hypertension (16,21%) or asthma (12,16%). 32 (42%) had prior biologic therapy, with treatment failure the most commonly reported reason for switch (26/33, 79%). Of the 47 participants with three-month data, 18 (38%) achieved DAS28 remission. The proportion of patients with high disease activity decreased markedly from 45 (58%) at baseline to three (6%) at three months and moderate disease activity from 32 (42%) at baseline to 14 (30% at three months). Concurrent corticosteroid use declined, from 13 (17%) patients at baseline to just three (5%) by three months. The mean exposure time was six months (IQR five to seven). Nine patients (9%) stopped UPA during the study period, (5/9 due to adverse events, 4/9 due to patient or physician choice). One case of shingles occurred, with temporary treatment interruption. Reports of serious adverse events were low (4% patients of events reported) with cases of serious and opportunistic infections reported most frequently (three cases). There were no reports of MACE or venous thromboembolic events. 1 report of malignancy (extranodal marginal zone B-cell lymphoma) was considered unrelated to treatment. Conclusion This preliminary analysis of an observational study provides valuable insights into the real-world effectiveness of UPA for treatment of moderate to severe RA with similar early efficacy to that observed in clinical trials. 38% of patients achieved clinical remission by 3 months, and adverse events were infrequent. Disclosure J. Taylor: None. S. Srirangan: None. M. Bukhari: Honoraria; M.B has received honoraria for speaking and attended advisory boards with Bristol-Myers Squib, UCB celltech, Roche/Chugai, Pfizer, AbbVie, Merck, Mennarini, Sanofi-aventis, Eli-Lilly, Janssen, Amgen, Novartis and Gilead. Other; M.B. has been sponsored to attend regional, national and international meetings by UCB celltech, Roche/Chugai, Pfizer, Abbvie, Merck, Mennarini, Janssen, Bristol-Myers Squib, Novartis and Eli-lilly. S. Bilgrami: Other; S.B. has received professional and financial support from Eli Lilly, UCB &amp; Pfizer. M.K. Nisar: Other; M.K.N undertakes clinical trials and received support (including attendance at conferences, speaker fees and honoraria) from Roche, Chugai, MSD, AbbVie, Pfizer, BMS, Novartis, Celgene, UCB and, Lilly. S. McDonald: None. N. Goodson: None. A. Allard: Other; A.A. has received payment for services, sponsorship, funding, grants or worked on clinical trials for AbbVie, Eli Lilly, Pfizer, Novartis, BMS, Roche. A. Kinder: None. M. Green: None. L. Hunt: None. S. Raizada: Honoraria; S.R. has received honoraria from AbbVie. B. Kirkham: Consultancies; B.K. has received consultant/speaker fees from AbbVie, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer and UCB. Grants/research support; B.K. has received research support from Eli Lilly and Novartis. E. Thomas: Other; E.T. has been on advisory boards for Janssen and Galapagos. R. Horsfall: None. S. Bartlett: None. R. Millward: None. V. Burton: None. J. Galloway: Consultancies; J.G. has received speaker/consultancy for AbbVie, Galapagos, Janssen, Lilly, Pfizer, UCB and Vifor. Grants/research support; He has received research grants for AbbVie, Galapagos, GSK, Janssen, Lilly, Pfizer.

Chinese expert consensus on the diagnosis and management of ocular adnexal extranodal marginal zone mucosa-associated lymphoid tissue lymphoma (2023 edition)

Ocular adnexal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (OAML) is a common malignant tumor that affects the ocular adnexal region. The incidence of OAML is increasing due to the aging population. The tumor invades the ocular adnexal region, which can result in abnormal ocular appearance and function, thereby reducing the quality of life. Currently, there is no standardized diagnosis and management guideline for OAML. To enhance the standardization of diagnosis and management in OAML, a collaborative effort was undertaken by esteemed organizations in China. The Cellular Immune Therapy Committee of China Association for Promotion of Health Science and Technology, the Ocular Tumor Committee of Chinese Medical Doctor Association for Ophthalmologist Branch, the Imaging Medicine Branch of Chinese International Exchange and Promotion Association for Medical and Healthcare, the Tumor and Microecology Professional Committee of China Anti-cancer Association, and the Lymphoma Immunotherapy Committee of Beijing Cancer Prevention Society jointly convened a panel of experts to develop the inaugural "Chinese Expert Consensus on the Diagnosis and Management of ocular adnexal extranodal marginal zone mucosa-associated lymphoid tissue lymphoma (2023 edition)"..

Histopathological staging and differential diagnosis of marginal zone lymphoma of gastric mucosa-associated lymphoid tissue

The purpose of this study was to explore the histopathological staging and differential diagnosis of marginal zone lymphoma in gastric mucosa-associated lymphoid tissue (MALT lymphoma). We performed detailed histomorphology and immunohistochemistry investigations as well as genetic testing on endoscopic biopsy and endoscopic mucosal resection specimens from 18 patients with gastric MALT lymphoma. We found that gastric MALT lymphoma typically begins as a small, isolated area outside the lymphoid follicular mantle zone or proliferates in a multifocal, patchy manner, gradually spreads to the interfollicular zone, forming diffuse proliferation, invades the gastric mucosal glands, and infiltrates or proliferates into the center of peripheral reactive lymphoid follicles. Abnormally proliferating lymphocytes invade the surrounding lymphoid follicles, resulting in damage, atrophy, and disappearance of their normal follicles as well as of the gastric mucosa glands, forming diffuse proliferation. Redifferentiation and proliferation lead to the transformation of lymphocytes; that is, MALT transitions into highly invasive lymphoma. Based on our findings in this study, we propose the following five stages in the process of development and progression of gastric MALT lymphoma: the stage of cell proliferation outside the lymphoid follicular mantle zone; the stage of heterogeneous proliferative lymphoepithelial lesion; the stage of reactive lymphoid follicular implantation; the stage of lymphoid follicular clonal proliferation; and the stage of MALT transforming into highly invasive lymphoma. We examined the differential diagnosis of histopathological features at each stage. The clinicopathological staging of gastric MALT lymphoma can help clinicians provide accurate treatment and track malignant cell transformation, thus playing a significant role in controlling its development and progression.

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.

A Case of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma with Special Endoscopic Morphology

A Case of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma with Special Endoscopic Morphology

Mucosa-Associated Lymphoid Tissue Lymphoma of the Labial Minor Salivary Glands: Case Report

Mucosa-Associated Lymphoid Tissue Lymphoma of the Labial Minor Salivary Glands: Case Report

Inhibition of the MALT1-LPCAT3 axis protects cartilage degeneration and osteoarthritis

The proinflammatory cytokines and arachidonic acid (AA)-derived eicosanoids play a key role in cartilage degeneration in osteoarthritis (OA). The lysophosphatidylcholine acyltransferase 3 (LPCAT3) preferentially incorporates AA into the membranes. Our recent studies showed that MALT1 [mucosa-associated lymphoid tissue lymphoma translocation protein 1]) plays a crucial role in propagating inflammatory signaling triggered by IL-1β and other inflammatory mediators in endothelial cells. The present study shows that LPCAT3 expression was up-regulated in both human and mice articular cartilage of OA, and correlated with severity of OA. The IL-1β-induces cell death via upregulation of LPCAT3, MMP3, ADAMTS5, and eicosanoids via MALT1. Gene silencing or pharmacological inhibition of LPCAT3 or MALT1 in chondrocytes and human cartilage explants notably suppressed the IL-1β-induced cartilage catabolism through inhibition of expression of MMP3, ADAMTS5, and also secretion of cytokines and eicosanoids. Mechanistically, overexpression of MALT1 in chondrocytes significantly upregulated the expression of LPCAT3 along with MMP3 and ADAMTS5 via c-Myc. Inhibition of c-Myc suppressed the IL-1β-MALT1-dependent upregulation of LPCAT3, MMP3 and ADAMTS5. Consistent with the in vitro data, pharmacological inhibition of MALT1 or gene silencing of LPCAT3 using siRNA-lipid nanoparticles suppressed the synovial articular cartilage erosion, pro-inflammatory cytokines, and eicosanoids such as PGE2, LTB4, and attenuated osteoarthritis induced by the destabilization of the medial meniscus in mice. Overall, our data reveal a previously unrecognized role of the MALT1-LPCAT3 axis in osteoarthritis. Targeting the MALT1-LPCAT3 pathway with MALT1 inhibitors or siRNA-liposomes of LPCAT3 may become an effective strategy to treat OA by suppressing eicosanoids, matrix-degrading enzymes, and proinflammatory cytokines.Graphical

Abstract 7583: Discovery of a potent small molecule MALT1 protease inhibitor for the treatment of cancer

Abstract The paracaspase mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), as the core component of CBM complex (CARD9/10/11/14-BCL10-MALT1), plays an essential role in activating the NF-κB pathway and regulating the cell proliferation, differentiation and immunity. Inhibiting of MALT1 is considered a promising therapeutic approach for the treatment of several non-Hodgkin B-cell lymphomas, chronic lymphocytic leukemia (CLL), solid tumors and autoimmune diseases. Herein, we report the discovery of a novel potent MALT1 allosteric inhibitor, BPI-530616, which strongly inhibited MALT1 protease activity with subnanomolar IC50, and low off-target activity on other proteases. BPI-530616 can inhibit the proliferation of B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell line, OCI-ly3, bearing CD79b and CARD11 mutations. The cell line is intrinsically resistant to covalent and non-covalent Bruton's Tyrosine Kinase (BTK) inhibitors. Meanwhile, BPI-530616 suppressed the cellular cytokine secretion (e.g.IL-10, IL-2) or MALT1 direct substrate cleavage (e.g. CYLD). In vivo, BPI-530616 dose-dependently suppressed tumor growth and inhibited the cleavage of CYLD in OCI-ly3 xenograft mouse model. To address the role of MALT1 inhibitor in the contest of immune-oncology, a CT26 syngeneic mouse model was set up. Oral administration of BPI-530616 exhibited a good antitumor effect comparable to that of the anti-PD1 antibody, with no observable adverse effects. Additionally, BPI-530616 displayed desirable drug-like properties, including low clearance and good oral bioavailability across multiple pre-clinical species. Taken together, our research has led to the discovery of a novel, potent, selective, and orally bioavailable small molecule MALT1 inhibitor, BPI-530616. It demonstrated anti-tumor efficacy in the DLBCL animal model and showed promising effects in an immune-oncology animal model. Citation Format: Yuzhen Zhou, Bang Fu, Jie Chen, Weidong Cai, Xiao Sun, Yinlong Li, Wei Ren, Qichao Shen, Guolong Du, Xiaojun Zhou, Zhengyao Zou, Haibo Chen, Xiaoyun Liu, Cheng Yang, Xiangyong Liu, Jing Guo, Hao Wu, Lieming Ding, Jiabing Wang, Hong Lan. Discovery of a potent small molecule MALT1 protease inhibitor for the treatment of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7583.

The potential value of ultrasound in predicting local refractory/relapse events in primary thyroid lymphoma patients.

Primary thyroid lymphoma (PTL) is a rare malignant disorder, and ultrasound plays an important role in PTL diagnosis and follow-up surveillance. Prediction of refractory/relapse events in PTL patients is an essential issue, yet no ultrasonic PTL features have been discovered to be related to refractory/local relapse events. From January 2008 to September 2022, newly diagnosed PTL patients in our center who underwent standard first-line treatment and received an ultrasound examination before treatment were enrolled. Data regarding patients' clinical and sonographic features, as well as their therapeutic responses were collected. Subjects with an ideal prognosis were compared to those with refractory/relapse events. In total, 37 PTL patients were analyzed, including 26 with diffuse large B-cell lymphoma, 2 with follicular lymphoma and 9 with mucosa-associated lymphoid tissue lymphoma. During the median follow-up of 25 months, 30 patients obtained a complete response, 4 were refractory patients, and 3 experienced local relapse. No significant difference was detected in the baseline clinical characteristics between patients with an ideal prognosis and those with refractory/local relapse events. In terms of sonographic features, however, an event-free survival (EFS) curve comparison revealed that patients with bilobar enlargement (defined as an anterior-posterior diameter > 2.5cm on both sides of thyroid lobes) had a poorer EFS than those without (P < 0.0001), and patients with diffuse type had a poorer EFS than those with mixed/nodular types (P = 0.043). No significant difference was observed in EFS between patients with or without signs of suspicious cervical lymph node metastasis, rich blood signal distribution or symptoms of trachea compression. PTL patients with an anterior-posterior diameter > 2.5cm for both thyroid lobes or PTL patients of the diffuse ultrasound type could be prone to refractory/local relapse events.

Endoscopic Features of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma without Helicobacter pylori.

Although gastric mucosa-associated lymphoid tissue (MALT) lymphoma without Helicobacter pylori (HP) has increased recently, a specific endoscopic classification has not been established; its endoscopic characteristics have not been investigated. In this study, we retrospectively investigated gastric MALT lymphoma without HP in our hospital and assessed differences in the endoscopic findings according to HP infection status. Fifty-seven patients with gastric MALT lymphoma Lugano stage I, diagnosed between January 2013 and March 2023, were divided into three groups (currently HP infected, previously infected, and uninfected), wherein their endoscopic findings were evaluated. Furthermore, the superficial type, as per the classification of Sano et al., was independently subdivided based on the endoscopic differential diagnoses, as follows: atrophic gastritis-like, angiodysplasia-like, superficial gastritis-like, and undifferentiated carcinoma-like. Compared with the currently infected group, the HP-uninfected group tended to have more small lesions without erosion and more discolored, undifferentiated carcinoma-like depressed lesions. In addition, the positive rate of the tree-like appearance (TLA) and ballooning characteristics of gastric MALT lymphoma in magnified findings was lower in the HP-uninfected group. In patients without HP infection, MALT lymphoma should be excluded, even in the absence of suspicious magnifying findings such as TLA or ballooning.

Role of H.pylori in Chronic Sore Throat by Using H.pylori Line.

Pharyngitis is an inflammation of the mucous membranes of the oropharynx. Pharyngitis may be caused by an infectious or noninfectious disease. Noninfectious diseases of pharynx include allergies, trauma, cancer, reflux and certain toxins. Infection with H. Pylori is associated with developing chronic sore throat, gastritis, gastric or duodenal ulcer, gastric cancer and MALT lymphoma. There are many different investigations to diagnose H pylori as H pylori antigen in blood and stool, urea breath test but, H. Pylori line is a new test for detection of the virulent strains. There are many lines of H pylori therapy in the form of PPIs and antibiotics for about two weeks. This study aimed to detect role of H pylori in chronic pharyngitis. 85 patients who had chronic pharyngitis with normal CBC, WBCS, lymphocyte, monocyte and eosinophils with negative ASO titer and throat swab. These patients did H pylori line to detect H pylori virulent antigen. 77 patients with chronic pharyngitis are positive H pylori and after medical treatment 68 patients became negative. H. Pylori line is a new test for detection of the virulent strains and screening H pylori carrier at risk of developing gastric and duodenal ulcers as well as cancer.

Long Term Clinical Outcomes of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: A Single Center Study

Objectives: Few studies have reported long-term follow-up after treatment of gastric mucosaassociated lymphoid tissue (MALT) lymphoma. In this single-center study, we investigated longterm treatment outcomes in patients diagnosed with gastric MALT lymphoma.Methods: The study included 80 patients diagnosed with gastric MALT lymphoma, who were followed up at a single center between January 2005 and December 2019 after &lt;i&gt;Helicobacter pylori&lt;/i&gt; eradication therapy, radiotherapy, or chemotherapy. We evaluated complete remission, improvement, or recurrence of the lesion. Follow-up over &gt;60 months was classified as long-term follow-up, and the progression-free survival rate was recorded.Results: Following &lt;i&gt;H. pylori&lt;/i&gt; eradication treatment, complete remission occurred in 85.9% (55/64) of &lt;i&gt;H. pylori&lt;/i&gt;-positive and 50.0% (3/6) of &lt;i&gt;H. pylori&lt;/i&gt;-negative patients. All patients with gastric MALT lymphoma who did not respond to &lt;i&gt;H. pylori&lt;/i&gt; eradication therapy (100.0% [6/6]) achieved complete remission following administration of local radiotherapy. We observed no deaths on long-term follow-up (&gt;60 months), and the progression-free survival was 101 months.Conclusions: In this study, patients with gastric MALT lymphoma showed excellent survival rates, progression-free survival, and prognosis on long-term follow-up. Prospective studies are warranted to determine the long-term prognosis of gastric MALT lymphoma after treatment.

Two lymphoma histotypes and papillary thyroid carcinoma coexisting on Hashimoto ground: a case report and review of the literature

BackgroundPapillary carcinoma is the most frequent type of thyroid carcinoma, while primary thyroid lymphoma is uncommon disease. The coexistence of these entities has already been described, and the common risk factor is considered Hashimoto thyroiditis. The two most frequent histotypes of primary thyroid lymphoma are diffuse large B-cell and mucosa-associated lymphoid tissue lymphoma, but the coexistence of both with papillary carcinoma is rarely reported.MethodsWe present a case of a previously healthy 57-years old male with rapidly growing lump on the right side of the neck. Ultrasonography revealed nodules in both thyroid lobes. Fine needle aspiration cytology and pertechnetate scintigraphy were performed. Due to the Bethesda T-5 in the “cold” nodule of the right lobe, surgery with histopathological and immunohistochemistry analysis was indicated.ResultsHistopathological and immunohistochemistry methods confirmed concomitant malignancies in the thyroid gland: diffuse large B-cell lymphoma and papillary carcinoma in the right, and mucosa-associated lymphoid tissue lymphoma in the left lobe with Hashimoto thyroiditis in the remaining tissue. Patient underwent therapy procedures and was without signs of local recurrence or metastatic spread on subsequent follow-up.ConclusionsSudden appearance of the neck mass in patients with Hashimoto thyroiditis should raise suspicion on primary thyroid lymphoma and be promptly taken in the diagnostic workup, including fine needle aspiration cytology. Pathology with immunohistochemistry is crucial for further clinical decision making. Since the standardized protocol in management of these complex patients is missing, personal approach and close collaboration between cytologist, pathologist, surgeon, haematologist and nuclear medicine specialist is essential.

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.

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.

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.

Gastric metastasis from breast cancer: five cases and a single-institutional review.

Gastric metastasis from breast cancer has a high rate of misdiagnosis and missed diagnosis. Data of patients who had gastric metastasis from breast cancer were retrieved from our hospital between 2014 and 2020. The gastric metastasis from breast cancer incidence was 0.04% (5/14,169 cases of breast cancer). Four patients had invasive lobular carcinoma, and the other patient had invasive ductal carcinoma. The time from the initial diagnosis of breast cancer to the appearance of gastric metastasis ranged from 0 to 12 years. One patient's endoscopic presentation was similar to mucosal-associated lymphoid tissue lymphoma and presented with gastric mucosal congestion and edema, widened wrinkles, mixed color fading, and redness. The initial pathological diagnosis of this patient was mucosal-associated lymphoid tissue lymphoma, and breast cancer was finally confirmed by immunohistochemistry. Hormonal receptors were highly expressed in four patients with primary and metastasis lesions and were negative in one patient. Human epidermal growth factor receptor 2 was negative in all patients. Mammaglobin and GATA3 were positive in all patients. In conclusion, the gastric metastasis of breast cancer incidence rate is low, and misdiagnosis can lead to insufficient or excessive treatment. Multiple biopsies and immunohistochemistry should be performed to diagnose gastric metastasis of breast cancer.

Primary pancreatic lymphoma: Histopathological pattern of 8 cases.

To report the histopathological pattern of primary pancreatic lymphoma (PPL) in 2 tertiary hospitals. The pathology slides and reports of all the cases diagnosed in pathology departments in 2 referral hospitals were reviewed. An additional immunohistochemistry study was done to reclassify lymphomas according to the current system. Eight patients with PPL have been identified. The ages ranged from 36 to 71 years. Clinical presentation includes abdominal pain, weight loss, jaundice, abdominal mass, nausea, and vomiting. Pathological evaluation revealed 5 diffuse large B-cell lymphomas, one high-grade B-cell lymphoma, one MALT lymphoma, and one follicular lymphoma. Primary pancreatic lymphoma is a very rare tumor without specific clinical, laboratory tests, or radiological findings. Abdominal pain is the most common clinical presentation. Diffuse large b-cell lymphoma is the most common pathological subtype. Primary pancreatic lymphoma should be taken into consideration when evaluating pancreatic mass to avoid unnecessary surgical resection.