Primary Lymphoma Research Articles

Prognostic factors and predictive models for primary pulmonary diffuse large B-cell lymphoma: a population-based analysis

ABSTRACT Background Primary pulmonary diffuse large B-cell lymphoma (PP-DLBCL) is a rare extranodal non-Hodgkin's lymphoma (EN-NHL). Its prognosis as an aggressive lymphoma is abysmal, and predictive models are still lacking. Methods We screened patients diagnosed with PP-DLBCL between 2010 and 2019 from the Surveillance, Epidemiology, and End Results (SEER) database. Then, univariate and multivariate COX regression analyses were used to identify independent risk factors affecting patient prognosis. Finally, a novel nomogram was constructed and the model was evaluated by looking at three dimensions. Results A total of 831 patients were included in this study. Most of the patients were elderly (526 (63.8%)) and female (428 (51.9%)). The included patients were randomized in a 7:3 ratio into a training group (577 (70%)) and a validation group (248 (30%)). We concluded that the independent risk factors of prognosis were age, extrapulmonary metastasis, radiotherapy, chemotherapy, and surgical intervention. The results of receiver operating characteristic curves, calibration curves, and decision curve analysis in the training and validation groups confirmed that the risk prediction nomogram could accurately predict the survival of PP-DLBCL. Conclusion This study is the first large population-based clinical data study on PP-DLBCL. A novel predictive model about prognosis has been developed to help clinical decision-making.

Pictorial Review of Rare Pancreatic Tumors and Tumor-like Lesions: Radiologic–Pathologic Correlation

Rare pancreatic tumors and non-neoplastic tumor-like lesions present a diagnostic challenge due to their uncommon occurrence and overlapping imaging characteristics with more prevalent pancreatic neoplasms. Advances in imaging technologies and diagnostic criteria have contributed to increased detection of these rare entities in clinical practice. This pictorial review focuses on the radiologic–pathologic correlation of rare pancreatic tumors, including colloid carcinoma, acinar cell carcinoma, pancreatoblastoma, primary pancreatic lymphoma, and non-neoplastic tumor-like lesions such as hamartomas and inflammatory pseudotumors. Detailed imaging features, such as signal intensities on MRI and enhancement patterns on CT, are correlated with pathological findings to assist in the differential diagnosis. Familiarity with these characteristics is crucial for radiologists to ensure accurate diagnosis and guide appropriate treatment strategies, as management and prognosis significantly differ from common pancreatic neoplasms.

CAR T-cell Therapy for Central Nervous System Lymphoma.

While anti-CD19 CAR T-cell therapy represents a major advance in systemic diffuse large B-cell lymphomas, central nervous system (CNS) lymphomas have been excluded from pivotal trials because of the fear of neurotoxicity. The purpose of this review was to assess the efficacy and tolerance of CAR T-cells in CNS lymphomas based on recently published studies. All the studies on CAR T-cell therapy for both primary and secondary CNS lymphomas reported high response rates (complete response rates ranging from 32 to 67%) in highly pre-treated patients. One-year PFS reached 40 to 60% in several studies. Neurotoxicity occurred in 36 to 68% of patients, including grade 3-4 neurotoxicity in 4.5 to 29% of patients. CAR T-cell therapy appears to be a very promising treatment in CNS lymphomas, with efficacy results close to those observed in systemic lymphomas. The toxicity profile, notably regarding neurotoxicity, is reassuring and should not prevent the development of CAR T-cells in the disease.

High-Dose Chemotherapy and Autologous or Allogeneic Transplantation in Aggressive B-Cell Lymphoma—Is There Still a Role?

Novel therapies such as CAR-T, BTK inhibitors and PD-1 inhibitors have changed the management of aggressive B-cell lymphomas. Nonetheless, these novel therapies have their own risk of late toxicities including second malignancies. They also create a subgroup of patients with relapse, treatment failure, or indefinite maintenance. We discuss the current role of autologous and allogeneic stem cell transplantation in this context. In patients with recurrent diffuse large B-cell lymphoma, CAR-T cell treatment has largely replaced autologous transplant. Autologous transplant should be considered in patients with late relapses and in selected patients with T-cell-rich B-cell lymphoma, where CAR-T cell therapy may be less effective. It also remains the treatment of choice for consolidation of patients with primary CNS lymphoma. In mantle cell lymphoma, intensive chemotherapy combined with BTK inhibitors and rituximab results in excellent outcomes, and the role of autologous transplantation is declining. In Hodgkin’s lymphoma, autologous transplant consolidation remains the standard of care for patients who failed initial chemotherapy. Allogeneic transplantation has lower relapse rates but more complications and higher non-relapse mortality than autologous transplantation. It is usually reserved for patients who fail autologous transplantation or in whom autologous stem cells cannot be collected. It may also have an important role in patients who fail CAR-T therapies. The increasing complexity of care and evolving sequencing of therapies for patients with aggressive B-cell lymphomas only emphasizes the importance of appropriate patient selection and optimal timing of stem cell transplantation.

Primary diffuse large B-cell lymphoma of bone in adults: A SEER population-based study.

Primary diffuse large B-cell lymphoma of the bone (PB-DLBCL) is an extremely rare type of extra-nodal lymphoma. The clinical characteristics, management, and survival outcomes of adult PB-DLBCL patients remain poorly defined. To explore the clinical manifestations, staging, therapeutic options, prognostic factors and outcomes of adult patients with PB-DLBCL and to create a model to predict survival outcomes. Data of adult PB-DLBCL patients were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program 18 registries database from 2000 to 2018. The Kaplan-Meier survival analysis was conducted to calculate survival rates. Univariate Cox regression, best subset selection (BESS), and least absolute shrinkage and selection operator (LASSO), followed by backward stepwise multivariable Cox regression, were used to construct the nomogram. The nomograms were evaluated using the concordance index (C-index), calibration curves and decision curve analysis (DCA). Diffuse large B-cell lymphoma (DLBCL) (67.51%) was the most frequent type of primary bone lymphoma. The most involved sites were the spine and lower-limb long bones. For the whole cohort, the 3-, 5-, 10- and 15-year overall survival (OS) rates were 74.9%, 70.5%, 60.0%, and 49.9%, and corresponding disease-specific survival (DSS) rates were 79.7%, 77.8%, 75.1%, and 71.4%, respectively. For OS, age, Ann Arbor stage, primary site and therapy were confirmed as final factors to develop the nomogram in adult PB-DLBCL patients, whereas for DSS, Age, marital status, Ann Arbor stage, number of bone lesions, therapy and year of diagnosis were confirmed as final factors in developing the nomogram. The nomograms demonstrated good accuracy and clinical utility. Established nomograms can accurately predict the survival of patients with PB-DLBCL and help clinicians optimize treatment.

Non-Invasive Imaging Including Line-Field Confocal Optical Coherence Tomography (LC-OCT) for Diagnosis of Cutaneous Lymphomas

Background/Objectives: Primary cutaneous lymphomas (PCL) are a heterogeneous group of non-Hodgkin lymphomas arising from malignant T (CTCL) or B (CBCL) cells, often mimicking other skin conditions. Recently, non-invasive diagnostic imaging modalities, including dermoscopy, Reflectance Confocal Microscopy (RCM), and Line-field Optical Coherence Tomography (LC-OCT), have become increasingly important, supporting clinicians in clinical practice. Hence, our study aimed to describe dermoscopic, RCM, and LC-OCT features of PCL and to explore their role in PCL management. Methods: Between December 2022 and January 2024, 40 lesions of 25 patients with PCL were retrospectively analyzed at the Dermatologic Unit of the University of Siena, Italy. Predefined dermoscopic, LC-OCT, and RCM criteria were assessed and their frequencies were calculated. Results: At dermoscopy, CTCL lesions were characterized by pinkish structureless areas (58,6%) and homogeneous distributed dotted vessels (35,7%), whereas 57.1% of CBCL presented with orange-yellow structureless areas. Considering CTCL, lymphocytes in the epidermis, dermal-epidermal junction, and dermis were detected by LC-OCT in 73.1%, 66.7%, and 51.9% and by RCM in 72.2%, 55.6%, and 61.1% of cases, respectively. The detection of lymphocytes was more precise using RCM than LC-OCT in CTCL (p < 0.001). Dermal infiltration of medium-reflective cells was visible in 80% and 40% of CBCL cases by LC-OCT and RCM, respectively. Conclusions: Non-invasive imaging techniques may support clinicians in managing PCL; however, further studies are mandatory in this field.

Antibody blockade of the PSGL-1 immune checkpoint enhances T-cell responses to B-cell lymphoma.

Despite advancements in cancer immunotherapy, most lymphomas remain unresponsive to checkpoint inhibitors. P-selectin glycoprotein ligand-1 (PSGL-1), recently identified as a promoter of T-cell exhaustion in murine melanoma models, has emerged as a novel immune checkpoint protein and promising immunotherapeutic target. In this study, we investigated the potential of PSGL-1 antibody targeting in B-cell lymphoma. Using allogeneic co-culture systems, we demonstrated that targeted antibody interventions against human PSGL-1 enhanced T-cell activation and effector cytokine production in response to lymphoma cells. Moreover, in vitro treatment of primary lymphoma cell suspensions with PSGL-1 antibody resulted in increased activation of autologous lymphoma-infiltrating T cells. Using the A20 syngeneic B-cell lymphoma mouse model, we found that PSGL-1 antibody treatment significantly slowed tumor development and reduced the endpoint tumor burden. This antitumoral effect was accompanied by augmented tumor infiltration of CD4+ and CD8+ T cells and reduced infiltration of regulatory T cells. Finally, anti-PSGL-1 administration enhanced the expansion of CAR T cells previously transferred to mice bearing the aggressive Eμ-Myc lymphoma cells and improved disease control. These results demonstrate that PSGL-1 antibody blockade bolsters T-cell activity against B-cell lymphoma, suggesting a potential novel immunotherapeutic approach for treating these malignancies.

Synchronous primary gastric diffuse large B-cell lymphoma and multiple lung primary adenocarcinoma with pulmonary cryptococosis: a case report and literature review

BackgroundThe coexistence of non-Hodgkin’s lymphoma of the stomach and multiple primary lung adenocarcinomas with pulmonary cryptococcosis has rarely been reported.Case presentationWe herein present a 75-year-old man who was admitted to our hospital due to hematemesis. Gastroscopy and imaging revealed extensive stomach wall thickening and multiple lung lesions, including nodules and cavernous lesion. The patient was diagnosed with primary diffuse large B-cell lymphoma via gastroscopy and bilateral lung primary adenocarcinoma with cryptococcal infection via percutaneous CT-guided puncture biopsy. He subsequently underwent six cycles of R-CHOP regimen for gastric lymphoma, along with CT-guided radiofrequency ablation for the upper lobe of the right lung primary adenocarcinoma and radioactive particle implantation was performed on the lower lobe of the left lung primary adenocarcinoma, supplemented with antifungal therapy. After a definite diagnosis and systemic treatment, the patient was followed up for twenty-seven months with no tumor recurrence, progression or metastasis.ConclusionTo the best of our knowledge, the complex combination of multiple primary malignancies and pulmonary cryptococcal infection is extremely rare. The diagnosis is been confusing and challenging. CT-guided needle biopsy can help achieve pathological diagnosis, elucidate the type and stage of the tumor, and even change the clinical treatment strategy, which is necessary and beneficial.

In situ optical feedback in brain tumor biopsy - a multipara-metric analysis

Abstract Introduction Brain tumor needle biopsy interventions are inflicted with non-diagnostic or biased sampling in up to 25% and hemorrhage, including asymptomatic cases, in up to 60%. To identify diagnostic tissue and sites with increased microcirculation, intraoperative optical techniques have been suggested. The aim of this study was to investigate the clinical implications of in situ optical guidance in frameless navigated tumor biopsies. Methods Real-time feedback on protoporphyrin IX (PpIX) fluorescence, microcirculation, and gray-whiteness was given before tissue sampling (272 positions) in 20 patients along 21 trajectories in total. The primary variables of investigation were fluorescence in relation to neuropathological findings and gadolinium (Gd) enhancement, increased cerebral microcirculation in relation to bleeding incidence, number of trajectories, and impact on operation time. Results PpIX fluorescence was detected in Glioblastoma IDH-wildtype CNS WHO grade 4 (n=12), Primary diffuse large B-cell lymphoma (n=3), astrocytoma IDH-mutated CNS WHO grade 4 (n=1) (Ki67 indices ≥15%). For two patients, no PpIX fluorescence or Gd was found, although samples contained tumorous tissue (Ki67 index 6%). Increased microcirculation was found along nine trajectories (34 sites), located in cortical, tumorous, or tentorium regions. Postoperative bleedings (n=10, nine asymptomatic) were related to skull opening or tissue sampling. The present study strengthens the proposed independence from intraoperative neuropathology as PpIX fluorescence is detected. Objective real-time feedback resulted in fewer trajectories compared to previous studies indicating reduced operation time. Conclusions The integrated optical guidance system provides real-time feedback in situ, increasing certainty and precision of diagnostic tissue before sampling during frameless brain tumor biopsies.

Primary splenic diffuse large B-cell lymphoma (PS-DLBCL) presenting in an asymptomatic patient after sports trauma

Primary splenic diffuse large cell lymphoma is unusual and accounts for 2% of all splenic lymphomas. The symptoms included left upper abdominal pain, indigestion, loss of appetite, generalized weakness, fever, anemia, and thrombocytopenia or elevated C Reactive Protein. The current case report, to our knowledge the first of its kind, presents unusual clinicopathologic findings, where the patient remained asymptomatic until the time of diagnosis but showed extensive splenic involvement with stage IV disease. Alternatively, the morphologic findings in this case were like to those seen in other Primary Splenic Diffuse Large B Cell Lymphoma reported in the literature. In conclusion, the present report emphasizes the need for additional case studies and research on the biology of this unusual subset of lymphoma.

Primary Mediastinal Large B-cell Lymphoma – A Case Report

AbstractPrimary mediastinal large B-cell lymphoma (PMBL) is an uncommon and aggressive subtype of non-Hodgkin large B-cell lymphoma that affects patients in the third and fourth decades of life. The objective of the present report is to describe the case of a male patient admitted to the emergency room with symptoms of dyspnea associated with signs of superior vena cava syndrome. The imaging exams revealed two masses in the mediastinum; the definitive diagnosis, established through an anatomopathological examination and immunohistochemistry, was of PMBL, and the patient was referred for chemotherapy.

Infected Primary Bone Mantle Cell Lymphoma with Multiple Vertebral Involvement

Primary vertebral lymphoma is an exceedingly rare entity. We hereby report a case of a 67-year-old male who presented to our department with fever, weight loss, and progressively worsening lower back pain radiating to the right hip. Physical examination showed pain on percussion of the dorsal and lumbar spine and tenderness on palpation of the right upper thigh area. The radiographic findings revealed numerous vertebral lesions with a right psoas abscess extending to the right upper thigh. Intravenous antibiotic therapy was initiated and the patient underwent an incision and drainage of the psoas abscess with a favourable outcome. However, given the suspicious imaging findings of the osseous lesions suggestive of malignancy, a vertebral biopsy was performed and yielded histo-pathological findings consistent with bone mantle cell lymphoma. To the best of our knowledge, this is the first case of an infected primary bone mantle cell lymphoma with multiple vertebral involvement. The diagnosis is challenging and can be confused with other diseases.

Primary cutaneous T-cell lymphoma not otherwise specified (NOS) uncovering a novel RAB27A variant in Griscelli syndrome type 2.

Griscelli syndrome type 2 (GS2) is a rare, autosomal recessive disorder that typically emerges during childhood. It manifests with partial albinism, silvery hair, immunodeficiency and hemophagocytic lymphohistiocytosis predisposition (HLH). Our findings suggest that lymphoproliferative disorders, including cutaneous lymphomas, should be considered part of the dermatological spectrum of GS2. While GS2 has previously been diagnosed in adults presenting with HLH, our observations indicate that HLH is not an inevitable outcome, even in patients who survive into their fifth decade of life.

Functional Targets for Epstein-Barr Virus BART MicroRNAs in B Cell Lymphomas

MicroRNAs are key post-transcriptional regulators of gene expression and their dysregulation is often linked to cancer. Epstein-Barr virus encodes 22 BamHI A Rightward Transcript (BART) miRNAs, which are expressed in nearly all EBV-associated cancers and implicated in viral pathogenesis. To investigate biological targets for BART miRNAs in B cell lymphomas, we performed a meta-analysis of publicly available Ago-CLIP datasets from EBV-positive Burkitt lymphomas (BLs), primary effusion lymphomas (PELs), AIDS-associated diffuse large B cell lymphomas (DLBCLs), and lymphoblastoid cell lines (LCLs). Our analysis focused on comparing targets of EBV BART miRNAs across the different types of transformed B cells. Using reporter assays, we then experimentally validated over 50 functional interactions between BART miRNAs and cellular protein-coding transcripts involved in activities such as B cell differentiation (PRDM1, IRF4, and MYC), cell cycle regulation (UHMK1, CDKN1A, MDM2, and NPAT), apoptosis (MCL1), signaling and intracellular trafficking (GAB1, SOS1, MAPK1, RAB11A, CAV1, and RANBP9), and tumor suppression (CCDC6). Moreover, ectopic BART miRNA expression in several EBV-negative BL cells induced transcriptional changes that may influence molecular signatures of EBV-associated BLs. Collectively, our findings reveal novel, functional interactions for BART miRNAs in lymphomas and provide insights into their roles in these B cell cancers.

Primary central nervous system diffuse large B-cell lymphoma with MYC and BCL2 rearrangements associated with deep brain stimulation device.

Primary central nervous system diffuse large B-cell lymphoma with MYC and BCL2 rearrangements associated with deep brain stimulation device.

Evaluating STING Agonist Impact on Kaposi’s Sarcoma-Associated Virus-related Cancers

Kaposi’s sarcoma-associated herpesvirus (KSHV) is an etiological agent of multiple malignancies associated with compromised immunity, such as Kaposi’s sarcoma (KS) and Primary Effusion Lymphoma (PEL). KSHV infection is lifelong with no available treatment or vaccines and poses a high risk to immunocompromised individuals. The virus is transmitted via the oral and sexual route, and has a biphasic life cycle with a short lytic replication cycle followed by long-term latency, with the expression of few genes making detection difficult. Reactivation from latency results in a cascade of viral gene expression and pathogenesis. Critical to controlling KSHV infection is the cGAS-STING DNA-sensing pathway (STING), known to activate the type I interferon response and induce cancer cell death or growth inhibition. STING exhibits both anti-viral and anti-tumor responses, showing promise as a protein of interest to study for the development of a therapeutic treatment. By examining the in vitro effectiveness of STING agonists in inhibiting KSHV oncogenesis in PEL, the study aimed to provide the foundation for a potential novel therapeutic approach. Six patient-derived PEL cell lines were treated with the STING agonist diaminobenzamidazole (diABZI) in a dose-dependent manner. Four of the PEL cell lines exhibited decreased cell growth, viability, and colony formation, while two PEL cell lines were resistant to treatment, correlating with the presence or absence of STING expression. RNA-sequencing was performed and discovered upregulation of multiple interferon-stimulated genes (ISG) in responsive cell lines. Further investigations will explore STING agonists’ inhibition of PEL oncogenesis in vitro via colony formation and in vivo using a PEL xenograft model with NSG mice. Successful completion of this project will offer insight into potential clinical treatments for targeting KSHV infection and reactivation.

Rapidly Progressive Primary Cutaneous Gamma Delta T-Cell Lymphoma With FYN Gene Alteration.

Primary cutaneous gamma delta T-cell lymphoma (PCGDTCL) is a rare type of non-Hodgkin lymphoma accounting for <1% of primary cutaneous T-cell lymphomas. The exact cause of PCGDTCL is not known, however, it is thought that chronic antigen exposure in the skin may lead to immune dysregulation at the site, resulting in abnormal proliferation of mature, post-thymic cytotoxic gamma delta T cells. Mutations are the most common genetic alteration seen in PCGDTCL, while structural abnormalities such as gene fusions are not common. We report a case of PCGDTCL with atypical immunophenotypic features, including expression of CD5 with lack of cytotoxic marker expression, and a structural alteration leading to FYN deletion at exon 8. Recently, it was described that a deletion of the area between FYN exon 8 and TRAF3IP2 intron 2 results in a novel FYN::TRAF3IP2 fusion in peripheral T-cell lymphoma, not otherwise specified. We describe our patient's clinical course, differential diagnosis, and potential implications of FYN deletion on disease pathogenesis. To our knowledge, this is the first report of an FYN structural alteration to be described in PCGDTCL.

A Diagnostic Challenge in the Biopsy of a Mammographic Abnormality

Abstract Introduction/Objective Primary breast marginal zone lymphoma (MZL) is an uncommon subtype of extranodal lymphoma, and its diagnosis presents challenges, particularly in distinguishing it from lymphoplasmacytic lymphoma (LPL). MYD88 L265P mutation has been identified in a subset of marginal zone lymphomas, comprising 6-9% of cases. This genetic alteration further complicates the differentiation between MZL and LPL in breast tumors. We present a case highlighting the diagnostic complexities associated with primary breast MZL. Methods/Case Report A 71-year-old female patient underwent mammographic screening, which revealed a suspicious lesion in her left breast. Subsequent PET scan showed a hypermetabolic area consistent with a primary breast lesion. Biopsy histology exhibited a diffuse atypical lymphoid infiltration with varying proportions of neoplastic lymphocytes. Immunohistochemical analysis revealed positivity for CD20, PAX5, BCL2, CD138, MUM1, and negativity for CD3, CD5, Cyclin D1, CD10, CD23, CD34, BCL6, TDT, CD30, GATA3, and CK AE1/3. Additionally, there was lambda light chain restriction, and the Ki67 proliferation rate index was approximately 50%. Fish analysis indicated abnormal BCL6 gene rearrangement. Molecular genetic testing confirmed the presence of MYD88 mutation with c.794T&amp;gt;C p.L265P. Notably, bone marrow biopsy showed no abnormalities, with normal hematopoiesis. Serum electrophoresis and immunofixation detected an IgM monoclonal protein with lambda light chain specificity. Results (if a Case Study enter NA) NA Conclusion The diagnosis of primary breast MZL was favored over LPL due to the absence of common LPL- associated symptoms such as bone marrow involvement. However, the distinction between these entities remains challenging, underscoring the importance of comprehensive diagnostic approaches integrating histopathology, immunohistochemistry, and molecular genetics. Further research is warranted to enhance diagnostic certainty in such cases, particularly as the management of MZL and LPL becomes increasingly specific with the advent of novel therapeutic agents and ongoing clinical trials.

A case of EBV-Negative Primary Intestinal Diffuse Large B Cell Lymphoma Involving Multiple Anatomic Sites and Lymph Nodes

Abstract Introduction/Objective Extranodal lymphomas in the gastrointestinal tract are rare, with colonic lymphomas representing less than 0.5% of colorectal neoplasms. The most common type is Non-Hodgkin lymphoma. Treatment typically involves chemotherapy and surgical resection, with prognosis depends on various factors including age, genetic alteration, and bone marrow involvement. Methods/Case Report An 82-year-old female patient presented with abdominal pain and constipation. Radiological imaging revealed a mass in the ascending colon extending to the ileum. Histological examination following biopsy revealed to be a diffuse large B-cell lymphoma (DLBCL) of germinal center origin. The resected specimen showed two separate centrally ulcerated fungating masses in the ileum (4 x 4 x 1 cm) and ascending colon (8.5 x 5 x 4 cm). Microscopic examination showed a diffuse infiltrate of large, discohesive, atypical lymphoid cells with vesicular chromatin and prominent nucleoli. Abundant mitoses and apoptotic bodies are evident. The lesional cells were diffusely infiltrating into the lamina propria, submucosa, muscularis propria, and serosa associated with geographic necrosis. The appendix was also transmurally involved by the neoplastic cells. Multiple pericolonic lymph nodes were also involved by the lesional cells (6/15). Immunnohistochemical stains showed the neoplastic cells are positive for CD20, CD10, BCL6, while negative for MUM1, BCL2, C-MYC, and EBER. Ki67 index was 70%. CMV was negative. FISH result for MYC gene rearrangement with reflex to BCL2 and BCL6 was negative, which excludes double/triple-hit high grade B-cell lymphomas. The patient received chemotherapy with R-CHOP after the surgery and stayed recurrence-free for 15 months. Results (if a Case Study enter NA) NA Conclusion We reported a case of EBV-negative primary intestinal diffuse large B-cell lymphoma with germinal center cell origin involving multiple anatomic sites and pericolonic lymph nodes in an elderly immunocompetent woman.

MALTomas of the lung: A Clinicopathologic Review

Abstract Introduction/Objective MALTomas of the lung are the most common primary lymphoma of the lung. They are rare in clinical practice and have an indolent nature with a good prognosis and are often asymptomatic upon diagnosis. We undertook a retrospective study to assess the clinical and pathologic features of primary MALTomas of the lung. Methods/Case Report A search for lymphomas of the lung was done in our institutional archive of pathology from 1993-2023. The clinical and pathological data were reviewed in detail. Results (if a Case Study enter NA) There were a total of 51 cases of MALTomas recorded. Ages ranged from 35-88 years with an average age of 65 years old. 32 of the patients were female and 19 were male. Twenty eight of these cases involved the right lung, 18 affected the left lung, 5 cases had synchronoous involvement bilaterally. Thirteen (13/51) cases had extrapulmonary involvement, including the bone marrow, stomach, lymph nodes, thyroid, endometrium, eye, small bowel and pleura. 1/51 had synchronous follicular lymphoma and 2/51 had metachronous lymphoma (one large cell and one small lymphocytic lymphoma). 15/51 patients had bone marow biopsies, one of which developed multiple myeloma 7 years later. 10/51 patients had synchronous gastrointestinal epithelial lesions (9 tubular adenomas and 1 carcinoid tumor). 1/51 patients had a synchronous adenocarcinoma of the lung. 18 of the cases showed plasmacytic differentiation (8 kappa restricted and 10 lambda restricted). Conclusion Primary MALTomas of the lung are low grade malignancies that can have a more complex clinical scenario, such as multifocality or synchronous/metachronous lesions which can complicate clinical management.