Mucosa-associated lymphoid tissue (MALT) lymphoma: a practical guide for pathologists

Spatially exploring RNA biology in archival formalin-fixed paraffin-embedded tissues

The capability to spatially explore RNA biology in formalin-fixed paraffin-embedded (FFPE) tissues holds transformative potential for histopathology research. Here, we present pathology-compatible deterministic barcoding in tissue (Patho-DBiT) by combining in situ polyadenylation and computational innovation for spatial whole transcriptome sequencing, tailored to probe the diverse RNA species in clinically archived FFPE samples. It permits spatial co-profiling of gene expression and RNA processing, unveiling region-specific splicing isoforms, and high-sensitivity transcriptomic mapping of clinical tumor FFPE tissues stored for 5 years. Furthermore, genome-wide single-nucleotide RNA variants can be captured to distinguish malignant subclones from non-malignant cells in human lymphomas. Patho-DBiT also maps microRNA regulatory networks and RNA splicing dynamics, decoding their roles in spatial tumorigenesis. Single-cell level Patho-DBiT dissects the spatiotemporal cellular dynamics driving tumor clonal architecture and progression. Patho-DBiT stands poised as a valuable platform to unravel rich RNA biology in FFPE tissues to aid in clinical pathology evaluation.

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.

Non-resolving pneumonia: primary pulmonary MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is an uncommon extranodal low-grade B-cell lymphoma. Pulmonary MALT lymphomas originate from bronchial MALT and are also referred to as bronchial-associated lymphoid tissue lymphomas. MALT lymphomas of the lung are slow-growing tumours and usually present as asymptomatic chronic alveolar opacities visible on chest radiographs or with non-specific pulmonary symptoms. Here we described a case of a male patient in his early 50s with cough and chest pain for 4 years. His CT chest scan showed consolidation in the lingula and left lower lobe. Histopathology of the specimen obtained from cryobiopsy of the lung lesion showed a dense monomorphic lymphoid infiltrate, and immunohistochemistry confirmed the diagnosis of MALT lymphoma. The prognosis of pulmonary MALT lymphomas is good with >80% 5-year survival rates. This case highlights that MALT lymphoma should be considered as a differential diagnosis while evaluating cases with non-resolving consolidation.

Spatially Exploring RNA Biology in Archival Formalin-Fixed Paraffin-Embedded Tissues

Spatial transcriptomics has emerged as a powerful tool for dissecting spatial cellular heterogeneity but as of today is largely limited to gene expression analysis. Yet, the life of RNA molecules is multifaceted and dynamic, requiring spatial profiling of different RNA species throughout the life cycle to delve into the intricate RNA biology in complex tissues. Human disease-relevant tissues are commonly preserved as formalin-fixed and paraffin-embedded (FFPE) blocks, representing an important resource for human tissue specimens. The capability to spatially explore RNA biology in FFPE tissues holds transformative potential for human biology research and clinical histopathology. Here, we present Patho-DBiT combining in situ polyadenylation and deterministic barcoding for spatial full coverage transcriptome sequencing, tailored for probing the diverse landscape of RNA species even in clinically archived FFPE samples. It permits spatial co-profiling of gene expression and RNA processing, unveiling region-specific splicing isoforms, and high-sensitivity transcriptomic mapping of clinical tumor FFPE tissues stored for five years. Furthermore, genome-wide single nucleotide RNA variants can be captured to distinguish different malignant clones from non-malignant cells in human lymphomas. Patho-DBiT also maps microRNA-mRNA regulatory networks and RNA splicing dynamics, decoding their roles in spatial tumorigenesis trajectory. High resolution Patho-DBiT at the cellular level reveals a spatial neighborhood and traces the spatiotemporal kinetics driving tumor progression. Patho-DBiT stands poised as a valuable platform to unravel rich RNA biology in FFPE tissues to study human tissue biology and aid in clinical pathology evaluation.

Pathologic Features of Miscellaneous Foregut Malignancies

Neuroendocrine neoplasms are a heterogeneous group of tumors that can occur in almost any organ and share a common neuroendocrine phenotype.

One case of sublingual gland mucosa-associated lymphoid tissue lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is a type of marginal zone B-cell lymphoma that occurs outside the lymph nodes in mucosal tissue. It accounts for 6-8 % of non-Hodgkin's lymphomas. MALT lymphoma of the salivary gland is a rare disease, with primary tumors in the salivary gland accounting for 2-5 % of salivary gland tumors. The most common site is the parotid gland (80 %), followed by the submandibular gland (14 %), minor salivary glands, and sublingual gland (5 %). Patients with salivary gland MALT lymphoma often have autoimmune diseases such as Sjogren's syndrome and rheumatoid arthritis. Primary malignant tumors of the sublingual gland account for less than 1 % of cases, and preoperative diagnosis is difficult, often requiring biopsy for confirmation. To our knowledge, there are no reports of MALT lymphoma arising from the sublingual gland. We report a case of MALT lymphoma originating from the sublingual gland in a patient with a history of hypertension, diabetes, cerebral infarction, and non-traumatic numbness of the right lower limb.

A case of colonic MALT lymphoma with intra-abdominal abscess and lung metastasis: A case report

RATIONALE

Colonic mucosa-associated lymphoid tissue (MALT) lymphoma is an unusual subtype comprising only 2.5% of all MALT lymphomas. Most cases of colonic MALT lymphoma are diagnosed at an early stage. Therefore, the clinical features of advanced-stage colonic MALT lymphoma have seldom been reported, and the endoscopic findings are not well established. In this study, we report the clinical and endoscopic characteristics of stage IV colonic MALT lymphoma and highlight the importance of repeat biopsy to figure out this rare disease.

PATIENT CONCERNS

The patient was a 68-year-old male complaining of hematochezia and lower left quadrant abdominal pain for the past 3 days.

DIAGNOSES

The patient had 3 masses and friable mucosal lesions in the colon. With the first colonoscopy and biopsy, he was initially diagnosed as having eosinophilic colitis. However, the first treatment with steroids did not show any response. Because of atypical clinical features and colonoscopic findings, a second colonoscopy and a repeat biopsy were performed, and the results were consistent with colonic MALT lymphoma arising in the colon. The patient was finally diagnosed with stage IV colonic MALT lymphoma accompanied by multiple distant metastases.

INTERVENTIONS AND OUTCOMES

The patient started to receive chemotherapy with a combination regimen of cyclophosphamide, vincristine, and prednisolone. The follow-up study after 3 months showed stable disease status based on response evaluation criteria in solid tumors.

LESSONS

This case report presents atypical clinical characteristics and colonoscopic findings of stage IV colonic MALT lymphoma. Clinical suspicion and repeat biopsy should be considered to diagnose this rare and diagnostically challenging cancer.

Primary appendiceal MALT lymphoma clinically masquerading as chronic appendicitis: A case report

INTRODUCTION AND IMPORTANCE

Mucosal associated lymphoid tissue (MALT) lymphomas are a type of extranodal indolent lymphoma. They appear in areas ordinarily devoid of lymphoid tissues and are frequently preceded by chronic antigenic stimulation. Primary MALT lymphoma is an extremely rare variant in the appendix.

CASE PRESENTATION

A 22-year-old man presented with recurrent abdominal pain of three months. CT scan of the abdomen showed appendiceal wall thickening with ileo-colic lymphadenopathy. The patient was managed with right hemicolectomy and the histopathological examination showed MALT lymphoma.

CLINICAL DISCUSSION

MALT lymphomas of the appendix are extremely rare. Chronic appendicitis is an uncommon but possible clinical presentation. Although imaging techniques are essential for making a diagnosis, histological analysis is what leads to a final diagnosis. While there are no specific recommendations for treating appendiceal MALTomas, prior case reports indicate that appendectomy and surveillance may be sufficient.

CONCLUSION

Primary MALT lymphoma is extremely uncommon in the appendix. It is indolent in nature and can manifest clinically as chronic appendicitis. The management for localized disease is surgery or radiotherapy. The prognosis is excellent regardless of the initial treatment modality.

Multi-Scale Hybrid Vision Transformer for Learning Gastric Histology: AI-Based Decision Support System for Gastric Cancer Treatment

Gastric endoscopic screening is an effective way to decide appropriate gastric cancer treatment at an early stage, reducing gastric cancer-associated mortality rate. Although artificial intelligence has brought a great promise to assist pathologist to screen digitalized endoscopic biopsies, existing artificial intelligence systems are limited to be utilized in planning gastric cancer treatment. We propose a practical artificial intelligence-based decision support system that enables five subclassifications of gastric cancer pathology, which can be directly matched to general gastric cancer treatment guidance. The proposed framework is designed to efficiently differentiate multi-classes of gastric cancer through multiscale self-attention mechanism using 2-stage hybrid vision transformer networks, by mimicking the way how human pathologists understand histology. The proposed system demonstrates its reliable diagnostic performance by achieving class-average sensitivity of above 0.85 for multicentric cohort tests. Moreover, the proposed system demonstrates its great generalization capability on gastrointestinal track organ cancer by achieving the best class-average sensitivity among contemporary networks. Furthermore, in the observational study, artificial intelligence-assisted pathologists show significantly improved diagnostic sensitivity within saved screening time compared to human pathologists. Our results demonstrate that the proposed artificial intelligence system has a great potential for providing presumptive pathologic opinion and supporting decision of appropriate gastric cancer treatment in practical clinical settings.

An Overview of Selected Bacterial Infections in Cancer, Their Virulence Factors, and Some Aspects of Infection Management

In cancer development and its clinical course, bacteria can be involved in etiology and secondary infection. Regarding etiology, various epidemiological studies have revealed that Helicobacter pylori can directly impact gastric carcinogenesis. The Helicobacter pylori-associated virulence factor cytotoxin-associated gene A perhaps plays an important role through different mechanisms such as aberrant DNA methylation, activation of nuclear factor kappa B, and modulation of the Wnt/β-catenin signaling pathway. Many other bacteria, including Salmonella and Pseudomonas, can also affect Wnt/β-catenin signaling. Although Helicobacter pylori is involved in both gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma, its role in the latter disease is more complicated. Among other bacterial species, Chlamydia is linked with a diverse range of diseases including cancers of different sites. The cellular organizations of Chlamydia are highly complex. Interestingly, Escherichia coli is believed to be associated with colon cancer development. Microorganisms such as Escherichia coli and Pseudomonas aeruginosa are frequently isolated from secondary infections in cancer patients. In these patients, the common sites of infection are the respiratory, gastrointestinal, and urinary tracts. There is an alarming rise in infections with multidrug-resistant bacteria and the scarcity of suitable antimicrobial agents adversely influences prognosis. Therefore, effective implementation of antimicrobial stewardship strategies is important in cancer patients.

"Speckled Enhancement" on Gd-EOB-DTPA Enhanced MR Imaging of Primary Hepatic Mucosa-associated Lymphoid Tissue Lymphoma

PURPOSE

To elucidate MRI features of primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma, particularly, the "speckled enhancement" on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI.

METHODS

The institutional review board approved this retrospective observational study and waived informed consent. Using our picture archiving and communication systems and electronic medical records, five patients histopathologically diagnosed as hepatic MALT lymphoma and clinically confirmed as primary lesions who had undergone dynamic contrast-enhanced (DCE)-CT and DCE-MRI with Gd-EOB-DTPA were identified from September 2009 to December 2020. Two radiologists assessed their CT and MRI data in consensus with a pathologist's advice.

RESULTS

Overall, five lesions in five patients were included in this study. Precontrast CT showed hypoattenuation in all lesions. In the arterial phase of DCE-CT, four lesions (80%) showed hyperattenuation, whereas all lesions showed iso- to hypoattenuation in the delayed phase. A vessel penetration sign was also observed in all lesions. On MRI, all lesions showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and restricted diffusion on diffusion-weighted images. Both DCE-CT and DCE-MRI with Gd-EOB-DTPA showed similar enhancement patterns, except for the hepatocyte phase. Notably, however, four out of five lesions showed characteristic "speckled enhancement" that refers to punctate positive enhancements within the low signal lesions on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI pathologically confirmed to be hepatocyte clusters that remained in the tumor.

CONCLUSION

Primary hepatic MALT lymphomas were characterized by arterial phase enhancement, restricted diffusion, vessel penetration sign, and more specifically "speckled enhancement" in the hepatobiliary phase of DCE-MRI with Gd-EOB-DTPA.

Linfoma MALT de glándula parótida. Descripción de un caso

Introducción y objetivo: Los linfomas de la glándula parótida son una entidad infrecuente. Presentamos un caso clínico de linfoma tipo MALT de parótida, describiendo sus métodos diagnósticos y de tratamiento más empleados. Descripción: Mujer de 69 años con tumoración asintomática en cola de parótida y visión de estructuras nodulares en imagen de TC y RM con PAAF negativa. Se realiza parotidectomía total hallando el diagnóstico de linfoma MALT de la zona marginal. Se completa tratamiento mediante esquema R-CHOP durante 4 meses, sin signos de recidiva al año. Discusión: El linfoma tipo MALT es un tipo de LNH relacionado principalmente con inflamación autoinmune crónica en el caso de aparición sobre glándulas salivales. Se presenta como una tumoración asintomática e inespecífica de crecimiento lento y se diagnostica mediante TC o RM en su mayoría de casos. El tratamiento se realiza mediante parotidectomía asociado a quimioterapia y/o radioterapia, con una tasa de supervivencia mayor al 80% en 5 años. Conclusiones: Los linfomas de glándulas salivales son poco habituales y ocasionalmente se diagnostican de manera inadecuada debido a su comportamiento benigno que mimetiza a tumores más familiares del área parotídea. Su sospecha y distinción son esenciales y no deben olvidarse en nuestro diagnóstico diferencial de masas parotídeas.

Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma Treated with Radiation Therapy: A Case Report and Review of the Literature

Introduction

Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma or MALToma) is a prevalent type of primary pulmonary lymphoma. Typically, the primary therapeutic approaches involve surgery or chemotherapy, although there have been instances of radiation therapy being employed.

Case Report

We present a case of pulmonary MALToma that exhibited progression despite rituximab therapy. Subsequently, the patient demonstrated a positive response to radiation therapy.

Conclusion

This case highlights the potential efficacy of radiation therapy as a treatment option for pulmonary MALToma, especially in cases where other conventional treatments like rituximab have proven ineffective. Further research and studies are warranted to better understand the role of radiation therapy in managing pulmonary MALToma and to determine optimal treatment strategies for patients with this condition.

Extranodal MALT Lymphoma in the Oral Cavity: A Series of Three Cases with Review of Literature

BACKGROUND

Diagnosis of MALT lymphoma in the oral cavity is challenging. There is a great overlap in the histopathologic, immuno-histochemical and molecular features of MALT lymphoma with reactive lymphoid proliferations. The literature shows a very few case reports of primary MALT lymphoma of oral cavity.

METHODS

We discuss the histopathologic, immuno-histochemical, cytogenetic features, treatment and behavior of 3 cases of primary MALT lymphoma oral cavity along with review of literature.

RESULTS

The age ranged from 40 to 57 years (male to female ratio = 2:1). The sites involved were hard palate, bilateral gingivobuccal sulcus and right buccal mucosa. The most common histology was centrocyte-like (2 cases). Lymphoepithelial lesions were absent. On immunohistochemistry, all tumors showed diffuse strong CD20 and bcl2 expression with strong and diffuse MNDA staining in one case. IgH; MALT1 translocation was not seen in any of these cases. One patient received local radiotherapy, one received steroids; while the case 3 received RCHOP (Rituximab, cyclophosphamide, hydroxydaunorubicin hydrochloride, vincristine and prednisone) chemotherapy. Two patients had complete remission while one had recurrence.

CONCLUSION

MALT lymphoma of oral cavity shows a wide spectrum of morphology with presence of transformed cells, that may lead to misdiagnosis of DLBL. Treatment guidelines are not well established but a tendency to excise MALT lymphomas of oral cavity has been observed. Nevertheless, MALT lymphoma of oral cavity appears to be an indolent disease.

CCR6 activation links innate immune responses to mucosa-associated lymphoid tissue lymphoma development

The genesis of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is driven by oncogenic co-operation among immunological stimulations and acquired genetic changes. We previously identified recurrent CCR6 mutations in MALT lymphoma, with majority predicted to result in truncated proteins lacking the phosphorylation motif important for receptor desensitization. Functional consequences of these mutational changes, the molecular mechanisms of CCR6 activation and how this receptor signaling contributes to MALT lymphoma development remain to be investigated. In the present study, we demonstrated that these mutations impaired CCR6 receptor internalization and were activating changes, being more potent in apoptosis resistance, malignant transformation, migration and intracellular signaling, particularly in the presence of the ligands CCL20, HBD2 (human b defensin 2) and HD5 (human a defensin 5). CCR6 was highly expressed in malignant B cells irrespective of the lymphoma sites. HBD2 and CCL20 were constitutively expressed by the duct epithelial cells of salivary glands, and also those involved in lymphoepithelial lesions (LEL) in salivary gland MALT lymphoma. While in the gastric setting, HBD2, and HD5, to a less extent CCL20, were highly expressed in epithelial cells of pyloric and intestinal metaplasia respectively including those involved in LEL, which are adaptive responses to chronic Helicobacter pylori infection. These findings suggest that CCR6 signaling is most likely active in MALT lymphoma, independent of its mutation status. The observations explain why the emergence of malignant B cells and their clonal expansion in MALT lymphoma are typically around LEL, linking the innate immune responses to lymphoma genesis.

Cutaneous mucosa-associated lymphoid tissue lymphoma complicating Sjögren's syndrome: A case report and review of literature

BACKGROUND

The association of Sjögren's syndrome (SS) and lymphoma is similar. Mucosa-associated lymphoid tissue (MALT) or extranodal marginal zone B-cell lymphoma was the most common lymphomatous histology in SS patients. MALT in SS patients is frequently located in the parotid gland, while MALT lymphoma of the skin with SS is an exceedingly rare entity that needs to be recognized.

CASE SUMMARY

A 60-year-old woman presented with a 3-year history of progressive dry mouth associated with a 1-year history of enlarging cutaneous nodules. Physical examination revealed two hard subcutaneous nodules on her right lower leg. The results of Schirmer’s test were positive, despite the absence of dry eyes. Labial salivary gland biopsy revealed lymphocytic infiltration and chronic inflammation with a focus score of 2. The patient was diagnosed with SS. She underwent resection of one cutaneous nodule, and histopathological analysis identified the nodule as MALT lymphoma. Her dry mouth symptoms improved, and the nodules decreased after 6 mo of treatment with hydroxychloroquine sulfate and chemotherapy (thalidomide, cyclophosphamide, and dexamethasone).

CONCLUSION

Lymphoma is a severe complication of SS, shown by the reported unique case of cutaneous MALT lymphoma with SS.

Ileal mucosa-associated lymphoid tissue lymphoma diagnosed after emergency surgery: A case report and literature review

Introduction and importance

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, also called MALT lymphoma, is one of the entities of marginal zone lymphomas. These lymphomas are originated from indolent B-cell lymphomas and involve many organs such as the gastrointestinal tract, salivary gland, skin, lung, thyroid or breast. Ileal MALT lymphoma is relatively rare and clinical symptoms are usually atypical.

Case presentation

We report a case of a 99-year-old man who admitted to the emergency department with increasing and colicky periumbilical pain, vomiting and constipation. Non-contrast-enhanced computed tomography suggested small bowel obstruction due to phytobezoar. Intraoperatively, surgeon discovered the tumor at the site of phytobezoar. Histologically, there was a diffuse infiltration comprised of small to medium sized lymphocytes with monocytoid features. Immunohistochemical result confirmed CD20 positive B-lymphocytes and the Ki-67 proliferation index was 10%. Ileal mucosa-associated lymphoid tissue lymphoma was diagnosed based on histological findings and immunohistochemistry.

Discussion

MALToma of the gastrointestinal tract is related to chronic antigenic, inflammatory bowel disease and malabsorption syndromes. However, the etiology of ileal MALToma is unclear. Moreover, symptom of ileal MALToma is really not typical and overleaped in the context of small intestinal obstruction. It should be differentiated small intestinal MALToma from immunoproliferative small intestinal disease and an alpha heavy chain disease.

Conclusion

Ileal MALT lymphoma remains little known in many previous studies. It is really difficult to preoperatively diagnose. The combination of clinical presentation, postoperative histology and immunohistochemistry contribute to diagnosis and carry out appropriate management.

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Ileal MALT lymphoma is relatively rare compared to others gastrointestinal MALT lymphomas and symptoms are usually atypical.

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A 99-year-old man was hospitalized with the symptoms of bowel obstruction.

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Emergency surgery, postoperative histology and immunohistochemistry confirmed ileal MALT lymphoma.

[Gastric MALT lymphoma - from pathogenetic insights to consequent deescalation of therapy]

Gastric MALT- (mucosa-associated-lymphoid-tissue) lymphoma represents the most frequent gastrointestinal lymphoma. For decades, surgery and later on radiation and chemotherapy were regarded as established therapy. Some 30 years ago, the pathogenetic role of Helicobacter pylori infection for the development of gastric MALT-lymphoma became evident. During the following years, the pathogenetic insights were consequently implemented into clinical medicine. This lead to a radical change of the therapeutic approach to these lymphoma. Nowadays, Helicobacter pylori eradication is the internationally established therapy of first choice. It is followed by lymphoma regression in most cases. The long-term prognosis of patients after exclusive eradication therapy is excellent, even if endoscopic and/or histological residuals persist and a watch-and-wait strategy is favored.The pathogenetic insights und their clinical application implicated a consequent deescalation of therapy of gastric MALT-lymphoma. This review summarizes the single steps of this development and gives a recommendation for the actual management of patients with gastric MALT lymphoma.

Pitfalls in gastrointestinal tract haematopoietic lesions

Specimens from the gastrointestinal (GI) tract are among the most commonly encountered in routine pathology practice worldwide. It is well known that the luminal GI tract is home to various areas rich in mucosa-associated lymphoid tissue (MALT), whether native or acquired. The latter may be particularly problematic due to its well-known predisposing factors such as Helicobacter pylori infection and autoimmune conditions. Nevertheless, native GI structures are often the subject of query, particularly in conditions that may mimic lymphoproliferative conditions, including infectious and inflammatory diseases. Herein, we describe and share common clinicopathological findings in our daily practice that are challenging to distinguish from subtle low-grade neoplastic lymphoproliferative disorders.

A single-center analysis of patients with extranodal marginal zone lymphoma of the breast

Breast extranodal marginal zone lymphoma (EMZL) is a rare malignancy. We performed the largest published to date single-center retrospective analysis of 13 patients with breast EMZL focusing on clinical characteristics and treatment-related outcomes. The rarity of this disease at our center was concordant with the prevalence reported in the literature, with breast EMZL comprising 2% of 654 MZL cases. Most patients presented with stage I-II disease however four (30.8%) patients had stage IV disease mostly due to occult bone marrow (BM) involvement. Interestingly, EMZL was frequently non-FDG avid (66.7%) on staging PET/CT. With a median follow-up of 3.1 years (range 5 months to 10.2 years), the 3-year progression free survival was 68.7% (95%CI 30.2%-88.9%) and overall survival 80.2% (95%CI 40.3%-94.8%). No patient experienced higher-grade transformation. Herein we show that localized breast EMZL can be effectively treated with radiation therapy providing long term disease control.

What you always wanted to know about gastric MALT-lymphoma: a focus on recent developments

The stomach is the most common site of origin for extranodal lymphomas, with extranodal marginal zone B-cell of the mucosa associated lymphoid tissue (MALT-lymphoma) being the predominant subtype. MALT-lymphoma develops in mucosa associated lymphoid structures acquired by infection or chronic antigenic stimuli and may therefore arise in almost any organ of the human body. In spite of histopathologic similarities between various organs upon first glance, recent findings suggest pronounced differences between different sites, with a variety of features specific to gastric MALT-lymphoma. The objective of this review is to sum up the current knowledge on pathogenesis, molecular pathology, clinical presentation and therapeutic approaches to gastric MALT-lymphoma with in-depth discussion of recent developments.

MALT Lymphoma of the Tongue in a Patient with Sjögren's Syndrome: A Case Report and Literature Review

Sjögren’s syndrome (SS) is a systemic chronic autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands, as well as oral and ocular dryness. Among the late complications, malignant lymphoma is the most serious complication of SS. The risk of lymphoma in patients with SS has been estimated to be approximately 7–19 times higher than that in a generally healthy population. Although various histologic subtypes of lymphoma can occur in patients with SS, mucosa-associated lymphoid tissue (MALT) lymphoma accounts for 48–75% of malignant lymphomas that are frequently located in the parotid gland. However, MALT lymphoma affecting the tongue in patients with SS is extremely rare. Here, we share our experience with a unique case of MALT lymphoma of the tongue, originating from the minor salivary gland tissue in a patient with SS. Through this case report, we emphasize that MALT lymphoma should be considered in the differential diagnosis of a tongue mass in patients with SS.

Transcription factors linked to the molecular signatures in the development of hepatocellular carcinoma on a cirrhotic background

Mechanisms underlying the regulation of gene expression in cancer have been surveyed for decades to find novel prognostic factors and new targets for molecular targeted therapies in cancer. Because most cases of liver cancer are associated with liver cirrhosis, we aimed to analyze the gene expression signatures and the gene regulatory mechanism in hepatocellular carcinoma (HCC) on a cirrhotic background using high-throughput data analysis. In the present study, three valid array-based datasets containing HCC and liver cirrhosis samples were obtained to identify common differentially expressed genes (DEGs). Moreover, a comprehensive data analysis was conducted based on RNA-Seq data and using Kaplan-Meier curve analysis to find molecular signatures that reduce patients' survival rate. Furthermore, we proposed a gene regulatory network (GRN) to explore the possible regulatory mechanism of these molecular signatures by transcription factors in HCC progression from cirrhosis. Besides, we analyzed protein-protein interactions, gene ontology (GO), and pathway enrichment to elucidate the cellular and molecular function of the GRN elements in HCC. In this way, we found a list of 231 molecular signatures in HCC derived from cirrhosis. We also found the importance of TCF4, RUNX1, HINFP, KDM2B, MAF, JUN, NR5A2, NFYA, and AR as key differentially expressed transcription factors (DETFs) in the progression of HCC from cirrhosis. In conclusion, the identified molecular signatures and their transcription factors propose candidate prognostic markers and possible molecular targets in the progression of HCC.

Helicobacter pylori Infection and Extragastric Diseases-A Focus on the Central Nervous System

Helicobacter pylori (H. pylori) is most known to cause a wide spectrum of gastrointestinal impairments; however, an increasing number of studies indicates that H. pylori infection might be involved in numerous extragastric diseases such as neurological, dermatological, hematologic, ocular, cardiovascular, metabolic, hepatobiliary, or even allergic diseases. In this review, we focused on the nervous system and aimed to summarize the findings regarding H. pylori infection and its involvement in the induction/progression of neurological disorders. Neurological impairments induced by H. pylori infection are primarily due to impairments in the gut-brain axis (GBA) and to an altered gut microbiota facilitated by H. pylori colonization. Currently, regarding a potential relationship between Helicobacter infection and neurological disorders, most of the studies are mainly focused on H. pylori.

Mantle cell lymphoma, malt lymphoma, small lymphocytic lymphoma, and follicular lymphoma of the oral cavity: An update

BACKGROUND

Although uncommon, mature small B-cell lymphomas may arise in the oral/maxillofacial area and oral pathologists must be aware of the key characteristics of these neoplasms to perform an accurate diagnosis. In this manuscript, we attempted to integrate the currently available data on the clinicopathological features of follicular lymphoma (FL), mantle cell lymphoma (MCL), extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT-L), and chronic lymphocytic leukemia/ small lymphocytic lymphoma (CLL/SLL) affecting these anatomical regions.

METHODS

An updated descriptive literature review was carried out and a detailed electronic search was done in multiple databases to gather all cases affecting the oral/maxillofacial region and palatine tonsils.

RESULTS

We observed that MALT-L was the most frequently reported subtype, followed by FL, MCL, and CLL/SLL. The palate was affected in a high proportion of cases and the most usual clinical presentation was an asymptomatic swelling. MALT-L and CLL/SLL neoplastic cells were strongly associated with small salivary glands. FL showed no gender preference, while MCL and CLL/SLL were more prevalent in males and MALT-L in females. Overall, cases were more common in elderly individuals. Patients' treatment and outcome varied, with MCL being the most aggressive neoplasm with a dismal prognosis in comparison to FL and MALT-L.

CONCLUSION

Despite the poor documentation in many of the cases available, especially regarding the microscopic and molecular features of tumors, this review demonstrated that the oral mature small B-cell lymphomas investigated share similar clinical presentation, but carry different prognostic significance, demanding an accurate diagnosis.

Involved-site radiotherapy for Helicobacter pylori-independent gastric MALT lymphoma: 26 years of experience with 178 patients

Treatment options for Helicobacter pylori-independent gastric mucosa-associated lymphoid tissue (MALT) lymphoma (GML) include surgery, immunotherapy, chemotherapy, and radiation therapy (RT). The purpose of this study was to investigate the efficacy and safety of RT and routine endoscopic surveillance, hypothesizing that most patients are curable with RT alone. We queried a single institution database at a tertiary referral cancer center for patients with H pylori-independent GML treated with RT between 1991 and 2017. Response was assessed by follow-up endoscopies (EGDs) starting 10 to 12 weeks post-RT. Computed tomography scans were also part of the follow-up program, and positron emission tomography was added when clinically appropriate. We identified 178 patients (median age, 63 years; range, 25-89 years); 86% had stage I disease, 7% had stage II disease, and 7% had stage IV disease. Median RT dose was 3000 cGy over 20 fractions. Ninety-five percent of patients exhibited complete pathologic response on posttreatment EGD. Two patients experienced grade 3 toxicity, and 2 patients experienced in-field secondary malignancies. Over a median follow-up of 6.2 years, 9.6% experienced local failures, and 11.8% developed distant sites of disease. Five-year and 10-year overall survival were 94% and 79%, respectively, from last date of RT. RT is a highly effective and safe treatment for GML with excellent overall survival and very rare acute or late treatment-related toxicities. Favorable outcomes from this large retrospective sample of patients provide credible and compelling support for RT as standard of care for H pylori-independent GML.

How can we assess and measure prognosis for MALT lymphoma? A review of current findings and strategies

INTRODUCTION

: MALT (mucosa associated lymphoid tissue) lymphoma is a distinct type of B-cell lymphoma characterized by extranodal manifestation and an indolent clinical course with 10-year survival rates up to 90%. However, transformation to aggressive lymphoma may occur and treatment is indicated in case of symptomatic or progressive disease.

AREAS COVERED

: This review covers clinical and biological features potentially related to prognosis and outcome of MALT lymphoma patients, as well as available prognostic tools and risk stratification systems with a focus on the MALT-IPI (international prognostic index) and the POD24 (progression of disease at 24 months) cohort. In addition, we address the role of watch-and-wait, the importance of defining the optimal time point for treatment initiation and the relevance of depth of remission, which appear to be some of the central questions for physicians involved in the care of MALT lymphoma patients. A computerized database search using PubMed® was performed to identify available publications on prognostic factors and risk stratification tools in MALT lymphoma.

EXPERT OPINION

: Despite the development of disease-specific risk stratification systems, there is no clear concept how to measure prognosis and tailor treatment. Careful observation of the individual clinical course is essential to assess the optimal time point of treatment initiation and avoid overtreatment, particularly in patients with disseminated disease. In addition, early detection of patients with histological transformation is necessary, as these patients face a poor prognosis.

Gastric Mucosa-associated Lymphoid Tissue Lymphoma: An Important Differential Diagnosis for a Rapidly Growing Gastric Subepithelial Tumor - A Case Report and Literature Review

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade lymphoma with a long median survival time because of its low proliferation rate. A 75-year-old man was referred to the hospital for hematemesis. Upper endoscopy revealed a 30-mm subepithelial tumor (SET). Abdominal CT and EUS revealed a homogeneously hypoechoic lesion arising from the second layer of the stomach, without distant metastasis. Laparoscopic wedge resection was performed. On microscopic examination, the tumor showed diffuse aggregation of small lymphoid cells with abnormal architecture. Neoplastic cells showed positive reactivity for CD20 and prominent lymphoepithelial lesions were observed. The urease breath test was also conducted, with a negative result. Our final diagnosis was <i>Helicobacter pylori</i>-negative MALT lymphoma (Ann Arbor classification I_E2), which is a rapidly growing SET pattern. This case highlights the importance of including gastric MALT lymphoma as a differential diagnosis for rapidly growing gastric SETs.

Recent advances upper gastrointestinal lymphomas: molecular updates and diagnostic implications

Approximately one-third of extranodal non-Hodgkin lymphomas involve the gastrointestinal (GI) tract, with the vast majority being diagnosed in the stomach, duodenum, or proximal small intestine. A few entities, especially diffuse large B-cell lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, represent the majority of cases. In addition, there are diseases specific to or characteristic of the GI tract, and any type of systemic lymphoma can present in or disseminate to these organs. The recent advances in the genetic and molecular characterisation of lymphoid neoplasms have translated into notable changes in the classification of primary GI T-cell neoplasms and the recommended diagnostic approach to aggressive B-cell tumours. In many instances, diagnoses rely on morphology and immunophenotype, but there is an increasing need to incorporate molecular genetic markers. Moreover, it is also important to take into consideration the endoscopic and clinical presentations. This review gives an update on the most recent developments in the pathology and molecular pathology of upper GI lymphoproliferative diseases.

Morphological and immunohistochemical approaches to the diagnosis of Hashimoto thyroiditis and mucosa associated lymphoid tissue lymphomas: An audit

Most cases of autoimmune hypothyroidism are due to Hashimoto thyroiditis (HT). It is sometimes difficult to distinguish HT from mucosa associated lymphoid tissue (MALT) lymphoma using cytology or histology alone. This has necessitated the use of immunohistochemistry and other molecular techniques. A descriptive study was undertaken to determine the prevalence of MALT lymphoma and other associations of HT using histopathological and immunohistochemical methods. For testing of kappa and lambda antibodies, paraffin sections were prepared for immunohistochemical staining using a peroxidase-antiperoxidase immune complex method. Immunostaining in HT, demonstrated a polyclonal lymphoid population, as evidenced by dual positivity for kappa and lambda staining cells, whereas MALT lymphoma revealed a monoclonal lymphoid population, with strong positivity for kappa immunostaining and lack of lambda light chain expression. The proportion of MALT lymphoma in surgically treated cases of HT in the present study was 3.5% (95% CI: 0%–8.3%). The common malignancy associated with HT was papillary carcinoma of the thyroid (8.8%). Among the benign conditions, nodular colloid goiter (7%) was more commonly associated. Although modern molecular techniques are available for the confirmation of lymphomas, they are more expensive, time consuming and are available only in a few centers. Strict morphological criteria can differentiate HT from MALT lymphoma, but in suspicious cases, paraffin section immunohistochemistry using light chain restriction can offer comparable and reliable results. Since papillary carcinoma and MALT lymphoma have been associated with HT, these patients require careful surveillance.

Is mucosa-associated lymphoid tissue lymphoma an infectious disease? Role of Helicobacter pylori and eradication antibiotic therapy (Review)

Mucosa-associated lymphoid tissue lymphoma (MALT) is seldom considered a diagnosis hypothesis in symptomatic patients. These lymphomas present as a main risk factor for chronic gastritis due to Helicobacter pylori infection. H. pylori leads to chronic inflammation, producing lymphoid tissue in the stomach mucosa (MALT) possibly leading to malignant transformation. Even though H. pylori remains one of the most important factors in the development of MALT lymphoma, it is not mandatory in the evolution of MALT lymphoma since high-grade lymphomas present a lower prevalence of H. pylori. The prevalence of H. pylori is indirectly proportional with the progression into the gastric wall. Mucosal and submucosal MALT lymphomas have a higher prevalence of the bacteria. However, genetic factors remain a risk factor especially if eradication treatment fails. Even though a low percentage of MALT lymphomas are H. pylori-negative, some respond to antibiotic eradication treatment. This can be explained either by the immunomodulatory effect of antibiotics or by other infectious sources such as Helicobacter heilmannii and Campylobacter jejuni (small bowel lymphoma). Treatment in MALT gastric lymphoma was a breakthrough since it was the first time in oncology where tumours were cured by antibiotic therapy, leading us to wonder if MALT lymphomas are infectious disease or not?

Mucosa-Associated Lymphoid Tissue Lymphoma of the Larynx

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphomas are a subtype of non-Hodgkin lymphoma stemming from marginal zone B-cells. In this case report, we present two patients with an extremely rare localization of MALT lymphoma to the larynx.

METHODS

Case 1 is of a 78-year-old male presenting with a six-month history of progressive hoarseness with a past medical history significant for marginal zone lymphoma of the right orbit. Diagnosis was confirmed with a biopsy for extranodal marginal zone B-cell lymphoma of MALT type. An FDG-PET scan was done but did not show any sign of FDG avid malignancy, including at the primary site. Case 2 is a 60-year-old female presenting with one year of worsening throat discomfort, intermittent cough, and dyspnea with exertion. Pathology confirmed a diagnosis of extranodal marginal zone B-cell lymphoma of MALT type.

RESULTS

Case 1 was treated with low-dose radiation at 4 Gy delivered over two fractions of 2 Gy each. Upon completion of radiation treatment, he reported a resolution of his hoarseness and normalization of his voice. A four-month follow-up in May 2018 with flexible nasolaryngoscopy revealed a normal exam with fully mobile vocal folds bilaterally and no evidence of left false vocal fold submucosal mass. At seven months following treatment, the patient died unexpectedly of unknown causes. Case 2 was treated with radiation at 30 Gy in 15 fractions over the course of one month. Following completion of radiation therapy, she had improvement of her sore throat, nausea, dysphagia, dysgeusia, and dry mouth. At 21-month follow-up, she had no evidence of disease.

CONCLUSION

This case report demonstrates that MALT lymphoma can present with much more benign and subtle symptoms. This highlights the importance of clinicians to keep broad differentials and consider MALT lymphomas in the setting of laryngeal masses.

Putative role of marginal zone B cells in pathophysiological processes

The maintenance of inner integrity of an organism is founded on the proper performance of two immunity branches, innate and adaptive immune responses. Recently, it became apparent that subset of splenic B cells named marginal zone B cells (MZB cells) exhibits unique developmental and functional features that bridge these two immunity branches. Strategically positioned at the site where blood and lymph are filtered, MZB cells represent a population of sentinels that rapidly proliferate and differentiate into IgM plasmablast cells when encountered with blood-borne, thymus-independent (TI) Ags. Moreover, MZB cells have intrinsic capability to induce potent CD4⁺ helper T cell response and cytokine production upon stimulation with soluble antigens. Due to their ability to overcome a time gap prior the establishment of the full adaptive response towards pathogens, MZB cells connect and direct innate and adaptive immunity. An additional interesting characteristic of MZB cells is capacity to function as regulatory cells in autoimmune processes. MZB cells may also contribute to the control of autoimmunity via the induction of tolerance by apoptotic cells. Importantly, in the clear association with inflammation and autoimmunity, MZB cells may transform into MALT lymphoma, representing a concurrence point for the infection, immunity and malignancy. This paper presents an insight into the complex biology of marginal zone B cells and their role in intertwining and directing innate and adaptive immune processes at the physiological and pathological level.

Second Cancers in a Patient with Gastric MALT Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B-cell lymphoma, which is thought to arise from a background of chronic immune stimulation, bacterial, viral, or autoimmune stimuli. Treatment advances have increased the number of MALT lymphoma survivors, but there is still debate as to whether these patients are at a higher risk of developing second cancers. This is a case of a long-surviving (>20 years) patient with multiple diagnosed malignancies following MALT lymphoma. We describe how modern oncological treatment plans can provide patients with prolonged survival and increased quality of life despite increasing age and multiple malignancies.

Linfoma no Hodgkin tipo MALT de la glándula parótida

Lymphomas of the salivary glands are a rare entity with a rare incidence. They are more commonly found on the parotid gland, followed by the submandibular and sublingual glands. The majority of parotid lymphomas are non-Hodgkin’s lymphomas and are considered to be derived from mucosal-associated lymphoid tissue (MALT). Reports of these cases are scarce and often misdiagnosed since: their manifestation is relatively benign, they have a localized behavior, a slow growth and the evolution takes several years. Key words: Type MALT lymphoma; parotid gland tumor

Depth of Remission Following First-Line Treatment Is an Independent Prognostic Marker for Progression-Free Survival in Gastric Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma responding to upfront treatment has an excellent outcome and no further therapy is recommended, even in the presence of residual disease. However, no data exist on the influence of initial depth of remission on progression-free survival (PFS). Methods: We investigated a correlation between PFS and depth of response, categorizing them as complete remission (CR), partial remission (PR) and stable disease (SD) in 137 consecutive patients at the Medical University Vienna. Results: All patients with Helicobacter pylori (H. pylori)-positive, localized disease received H. pylori eradication (70%, 96/137), while the remaining patients were treated with various modalities. The response rate was 67% for the entire collective and 58% for eradication only, with corresponding CR-rates of 48% and 38%. At a median follow-up of 56.2 months, the estimated PFS for the entire cohort was 34.2 months (95% Confidence Interval 16.0–52.4). Responding patients (=CR/PR) had a significantly longer PFS compared to SD (68.3 vs. 17.3 months, p < 0.001). This was also applicable to the eradication only cohort (49.0 vs. 17.3 months, p < 0.001) and remained significant after correction for MALT-IPI. Furthermore, CR significantly prolonged PFS over PR (p = 0.007 entire cohort, p = 0.020 eradication). Conclusions: Remission status correlated significantly with PFS, suggesting depth of remission as prognostic marker for long-term relapse-free survival.

Appendix Tumor Microenvironment

The pathological features of the appendix tumors fundamentally recall those of the more frequent colorectal neoplasms, although with a higher relative incidence of carcinoids, due to the abundant presence of enteroendocrine cells in the appendix wall. Moreover, different types of lymphomas, Hodgkin and non-Hodgkin, arising from the extra-nodal mucosal-associated lymphatic tissue, can be encountered. The appendix tumor microenvironment (TME) consists of a cellular component and of a noncellular component: the former includes the immunocompetent cells, while the latter represents the support stroma. Particularly in carcinoids, the immune cell reaction can be explicated by tumor-infiltrating lymphocytes, which, in some circumstances, may arrange around and inside the tumor in a brisk fashion influencing favorably the prognosis. This active reaction has to be distinguished from any preexisting inflammatory condition of the appendix and from superimposed tumor complications, such as infection or ischemia. In practice, we consider the appendix TME a complex framework with immunological, mechanic, and metabolic functions, all supported by a marked neo-lymphoangiogenesis.

Non- Hodgkin lymphoma of the lips: A rare entity

AIM

To investigate clinico-pathological features of lymphoma of the lips, and review the literature.

MATERIALS AND METHODS

Retrospective analysis and review of English literature, 1996-2016.

RESULTS

Analysis included 23 cases, 7 new cases and 16 from literature, 12 M: 11 F, age 7-82 years. Four occurred in children, mean age 10.1; 19 in adults, mean 61.1 years. The lower lip was involved in the majority of cases (16, 69.56%). 14 (60.87%) were isolated to the lips, 8 (34.78%) were multifocal. Nine (39.13%) occurred in association with Sjogren's syndrome, of which one also had Hashimoto thyroiditis. IgG4-related disease and HIV were reported in one case each. The lip salivary glands were involved in most cases (19, 82.6%); 3 (13.6%) showed only cutaneous involvement. The typical presentation was single or multiple nodules (15, 65.21%), with surface ulceration in only two (8.69%). Constituent symptoms were absent in all cases, paresthesia was reported in one (4.34%). The majority (18, 78.26%) was extranodal marginal zone B-cell lymphoma - mucosa-associated lymphoid tissue lymphoma (EMZB-MALT), and one case each was mantle cell, NK-T cell, CD30 positive and plasmablastic lymphoma.

CONCLUSION

The lips seem to have a unique pattern of non-Hodgkin lymphoma dominated by EMZB-MALT lymphoma, rarely other types. In more than half, neither Sjogren's syndrome nor other chronic inflammation was identified. Lesions tend to present as asymptomatic slowly progressing, non-ulcerated submucosal masses. Lymphoma should be considered even in the absence of constituent symptoms, as most cases showed none. Although the number of reported cases is rather small, disease course is usually prolonged and prognosis seems to be good.

Association Between Gastric Lymphoid Follicles (Precursor Of MALT Lymphomas) And H. pylori Infection At A Referral Hospital In Iran

Purpose

Mucosa-associated lymphoid tissue (MALT) is the most common endoscopic finding in Helicobacter pylori positive patients that can progress to MALT lymphoma after a prolonged antigenic contact. This study was aimed to evaluate the prevalence of lymphoid follicles and aggregates (precursors of MALT lymphomas) in gastric mucosal biopsies and their correlation with H. pylori infection.

Patients and methods

In this study, 100 patients who had undergone an upper gastrointestinal endoscopy were enrolled. Five biopsy specimens were taken each patient through screening endoscopy and histopathological changes were evaluated and graded using the Wotherspoon System. The clinical background and H. pylori infection status were also investigated.

Results

Among the 100 cases in our series, 79 patients (79%) showed evidence of MALT in at least one biopsy specimen taken from the stomach and 21 cases (21%) had no evidence of MALT. H. pylori infection was detected in 74 (74%) patients. Lymphoid follicles were detected more frequently in H. pylori-positive patients (59%) compared to H. pylori-negative cases (3%) (P<0.001).

Conclusion

The frequency of lymphoid follicles and aggregates in gastric mucosal is associated with H. pylori infection. Further community-based studies in larger sample sizes using a combination of microscopic methods and PCR assay are required for effective monitoring of H. pylori infection.

[Histopathological classification of chronic B-lymphoproliferative disorders]

Chronic lymphoproliferative disorders should be classified according to the revised 2016 WHO classification. Biopsies are not mandatory for all chronic lymphoproliferative disorders as blood or bone marrow cytologroachical approach can be sufficient for some lymphoma entities. Diagnostic is based on a multidiscplinary approach taking into account clinical presentation, histopathological, cytological, immunophenotypical features (immunohistochemistry and Flow cytometry) and molecular pattern (translocation by FISH, Mutations landscape by NGS, and genomic abnormalities by CGH array). An important heterogeneity of clinical presentation and prognosis arises within the same lymphoma subtype. Clinical evolution is characterized by relapses, cytological progression and transformation into diffuse large B cell lymphoma, aggressive lymphoma or high-grade lymphomas.

Primary Pulmonary Involvement in Mucosa-associated Lymphoid Tissue Lymphoma

Pulmonary nodules have a broad differential diagnosis with primary lung cancer, lung metastases, benign tumors, carcinoid tumors, and infectious granulomas as their common cause. While relatively rare, pulmonary lymphoproliferative disorders such as primary pulmonary lymphomas, primary pulmonary plasmacytomas, secondary lymphomas involving the lung, multiple myeloma involving the lung, leukemias involving the lung should be considered in these patients presenting with lung nodules. Primary pulmonary non-Hodgkin’s lymphoma (NHL) is an extremely rare lung tumor accounting for 0.4% of all lymphomas. Mucosa-associated lymphoid tissue (MALT) lymphoma accounts for about 70%-90% of all primary pulmonary lymphomas, constituting less than 0.5% of all the lung neoplasms. Though it usually remains localized, it is a clonal B-cell neoplasm with a potential for systematic spread and transformation to an aggressive B-cell lymphoma. We hereby discuss the case of a 66-year-old woman with primary pulmonary MALT lymphoma.

Transformed mucosa-associated lymphoid tissue lymphomas: A single institution retrospective study including polymerase chain reaction-based clonality analysis

Given the lack of consistent data regarding the clinico-pathological features and clonal lymphomagenesis of patients with mucosa-associated lymphoid tissue (MALT) lymphoma and histological transformation (HT), we have systematically analysed 379 patients (32% gastric, 68% extra-gastric; median follow-up 52 months) diagnosed with HT at the Medical University Vienna 1999-2017, and reassessed tissues of identified patients by polymerase chain reaction (PCR)-based clonality analysis. HT was documented in 12/379 patients (3·2%) and occurred at a median time of 22 months (range; 6-202 months) after diagnosis of MALT lymphoma. By PCR-based clonality analysis, we detected a clear-cut clonal relationship of MALT lymphoma and diffuse large B-cell lymphoma (DLBCL) in 8 of 11 analysed cases proving that the large majority of DLBCL following MALT lymphoma are clonally-related and constitute a real transformation. Interestingly, HT occurred within the first 2·5 years after diagnosis in patients with clonal relationship, whereas time to aggressive lymphoma was longer in patients identified as clonally-unrelated (most likely secondary) lymphoma (82-202 months), suggesting that HT is an early event in this disease. Survival of patients with HT was poor with 6/12 dying at 1·5-33 months after HT, however, patients with localized gastric transformation had a superior outcome with only 1/6 dying due to progression of lymphoma.

Hematologic Malignancies of the Breast: A Contemporary Series Investigating Incidence, Presentation, Accuracy of Diagnosis on Core Needle Biopsy, and Hormone Receptor Expression

Background

Distinguishing breast hematologic malignancies in core needle biopsies from other entities can be challenging. Misclassification as a breast carcinoma could result in inappropriate treatment. The aim of this study was to characterize the types, incidence, and helpful diagnostic features of hematologic malignancies of the breast.

Design

All hematologic malignancies of the breast diagnosed at our institution from 2004 to 2017 were identified. Clinical notes, imaging, and slides were reviewed. Immunohistochemical analysis of estrogen receptor α (ERα), estrogen receptor β (ERβ), and androgen receptor (AR) was performed when tissue was available.

Results

In all, 43 hematologic malignancies from biopsies of 37 women and 6 men were identified. Core needle biopsies (35 or 81%) were more common than excisions (8 or 19%). For 14 patients (40%), the core biopsy was the first diagnosis of a hematologic malignancy. Diagnoses included 37 lymphomas (7 primary), 4 leukemias, and 2 myelomas. There was 1 misdiagnosis of carcinoma. Low positivity for hormone receptors was observed in a minority of lymphomas. A definitive diagnosis of hematologic malignancy was made in 31 (89%) of the core needle biopsies. Only 3 patients undergoing core biopsy required excision for diagnosis.

Conclusions

Most of the hematologic malignancies of the breast are currently diagnosed on core needle biopsy and 40% of patients do not have a prior history. To avoid errors, pathologists need to be aware of diagnostic features and morphologic mimics. A hematologic malignancy should be considered if tumor cells are discohesive, carcinoma in situ is absent, and hormone expression is low or absent.

Tongue Lumps and Bumps: Histopathological Dilemmas and Clues for Diagnosis

Exophytic lesions of the tongue encompass a diverse spectrum of entities. These are most commonly reactive, arising in response to local trauma but can also be neoplastic of epithelial, mesenchymal or miscellaneous origin. In most cases, the microscopic examination is likely to provide a straightforward diagnosis. However, some cases can still raise microscopic diagnostic dilemmas, such as conditions that mimic malignancies, benign tumors with overlapping features and anecdotal lesions. A series of "lumps and bumps" of the tongue are presented together with suggested clues that can assist in reaching a correct diagnosis, emphasizing the importance of the clinico-pathological correlations.

A young man with an unchanged consolidation in chest CT

Primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is extremely rare. MALT lymphoma patients usually show no clinical symptoms or physical signs. Chest radiograph or computed tomography (CT) may confuse MALT lymphoma with other pulmonary diseases, which would lead to misdiagnosis or a delayed diagnosis. In the present study, a 33-year-old male patient had cough and fever. Chest CT showed consolidation on both sides. Those clinical symptoms disappeared after he had been misdiagnosed and treated for community-acquired pneumonia for three weeks. However, further chest CT still showed the consolidation without any change. Then an ultrasonic guided transthoracic needle biopsy was performed. Morphological changes indicated the diagnosis of extranodal marginal Zone B cell lymphoma of MALT. The patient was then treated with chemotherapy and rituximab. After this line of treatment, the consolidation decreased.

Mucosa-associated lymphoid tissue lymphoma with metachronous involvement of the palpebral conjunctiva and bronchus: A case report

A 61-year-old woman with a history of palpebral conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma, treated with rituximab, was referred to the authors' hospital after follow-up positron emission tomography/computed tomography revealed ¹⁸F-fluoro-2-deoxy-d-glucose uptake in a tumor located in the left main bronchus. The diagnosis of MALT lymphoma was made by pathological and immunohistochemical findings homologous to previous palpebral conjunctival lesion via bronchoscopic biopsy. The disease was controlled with rituximab, cyclophosphamide, oncovin, and prednisolone (i.e., R-COP) chemotherapy. Although MALT lymphoma occurs in several organs, metachronous occurrence in the palpebral conjunctiva and bronchus is especially rare, and careful check-up is required to monitor for occurrence of systemic relapse.