Importance of extensive staging in patients with mucosa-associated lymphoid tissue (MALT)-type lymphoma

Transformation of MALT lymphoma to pure plasma cell histology following treatment with the anti-CD20 antibody rituximab

Mucosa associated lymphoid tissue (MALT) lymphoma is a relatively common lymphoma arising from marginal-zone B-cells which are closely related to plasma cells. As opposed to the large majority of plasma cells, MALT lymphoma cells express CD20, and the anti-CD20 antibody rituximab has been reported as active treatment in patients with MALT lymphoma. We present a patient with MALT lymphoma involving stomach and lung which transformed to a pure plasma cell tumor after therapy with rituximab. This observation again supports the close association between the cell of origin of MALT lymphoma and plasma cells, suggesting that "plasmacytoma of the GI-tract" as anecdotally reported may in fact be a MALT lymphoma with extreme plasmacytic differentiation. In addition, our findings suggest that MALT lymphomas with plasmacytic differentiation might have a different 18F-FDG uptake as compared to classical MALT lymphoma.

Early-stage gastric MALT lymphoma: is it a truly localized disease?

Early-stage gastric mucosa-associated lymphoid tissue lymphoma (GML) is considered a localized disease with an indolent course. Circulating malignant cells have been detected in other early-stage indolent lymphomas by molecular methods. We investigated the incidence of occult blood disease in early-stage GML patients, its impact on clinical outcome, and the similarity between blood and gastric lymphocytic clones. Sixty-two patients with localized GML were included in the study; 51 of them had Helicobacter pylori infection. Monoclonality was investigated by leader polymerase chain reaction. Sequencing was performed for the immunoglobulin variable gene (VH) analysis. Blood involvement was absent in all patients by conventional staging methods. In the whole group of 62 patients, the incidence of blood IgH rearrangement was 45%, and this did not correlate with baseline patient characteristics. The monoclonal blood and gastric products of five patients were sequenced and compared with each other. Clonal identity was evident in four of five patients. The VH3 gene was the most frequently used, both in the blood and in the stomach. Early-stage GML is not a truly localized disease because half the patients had a circulating clone, probably identical to the gastric one. The clinical significance of occult blood disease and the potential appropriate intervention need to be further investigated.

Methylation and API2/MALT1 fusion in colorectal extranodal marginal zone lymphoma

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is rarely found in the large intestine. Because of its rarity, the underlying epigenetic and genetic changes in the pathogenesis and prognostic factors have yet to be well established. For this purpose, methylation profiles and API2/MALT1 fusion in marginal zone B-cell lymphoma of MALT in the colorectum were studied and compared with treatment outcomes. For methylation analyses, 7 independent CpG islands (p15, p16, DAP kinase, hMLH1, MINT1, MINT2, and MINT31) were examined and RT-PCR for detection of API2/MALT1 fusion transcripts were performed in 15 colorectal marginal zone B-cell lymphoma of MALT in a single institution. Marginal zone B-cell lymphomas of MALT from both gastric and colorectal locations were also examined. In methylation analyses (n=13), 8 of 13 (62%) cases were classified as CIMP (CpG island methylator phenotype)-positive. Methylation was more frequently observed in cases with advanced disease stages than with earlier stages; an average of two methylated loci for earlier stages (IE or IIE) versus four loci in advanced ones (IVE; P=0.02). The estimated 5-year progression-free survival was 42% for CIMP-positive and 100% for CIMP-negative cases (P=0.03). API2/MALT1 fusion transcripts were found in two of nine cases (22%). In two cases with concurrent gastric and colorectal involvement of marginal zone B-cell lymphoma of MALT, methylation patterns and API2/MALT1 fusion results were different by location. Our results suggest that methylation profiles define a clinically more aggressive subgroup and multiclonal origin for marginal zone B-cell lymphoma of MALT with multiorgan involvement.

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue arising in the extracranial head and neck region: a high rate of dissemination and disease recurrence

Nongastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma, although generally indolent in nature, has variable and heterogeneous clinical course and biologic behavior. We have evaluated the clinical features and follow-up of patients with MALT lymphomas involving the head and neck in our institution. Forty-four new patients with MALT lymphomas arising in ocular adnexa (24 patients, group A) and other head and neck sites (20 patients, group B) of the salivary gland (13), thyroid gland (3) and other regions (4) were retrospectively analyzed. At initial diagnosis, 21 patients had solitary lesions (16/24 in the group A vs. 5/20 in the group B, P=.008); 23 had disseminated disease at multiple sites (11 patients) and/or lymph node involvement (15 patients: 3/24 in the group A vs. 12/20 in the group B, P=.025). Treatment consisted of local therapy, consisting of surgical resection and/or radiotherapy, in 34 patients and systemic chemotherapy with/without local therapy in 10 patients. Eight patients experienced tumor recurrence: four patients died of disease, two were alive with disease, and two were disease-free at last follow-up. With a mean follow-up of 46 months, the 5-year overall survival and relapse-free rates were 83% and 74%, respectively, which did not differ between the two groups (P>.5). Patients with MALT lymphomas of the head and neck are at relatively high risk for multifocal or lymph node involvement. Recurrence at prolonged times after therapy indicates the need for close long-term monitoring, and for prospective trials to prevent recurrence.

Pathology and clinical course of MALT lymphoma with plasmacytic differentiation

BACKGROUND

The feature of plasmacytic differentiation (PCD) is present in up to 30% of patients diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma. To date, the influence of PCD on the clinical course of MALT lymphoma has not been assessed.

PATIENTS AND METHODS

Therefore, we have retrospectively analysed the clinical characteristics and the course of the disease in 34 (25%) patients with PCD as compared with 101 (75%) MALT lymphoma patients without this histological feature.

RESULTS

Patients with PCD had significantly more extragastric lymphomas [28 of 34 (82%) versus 54 of 101 (53%), P = 0.003] and a significantly lower rate of t(11;18) [2 of 26 (8%) versus 22 of 72 (31%), P = 0.02]. There was no significant difference of age at diagnosis (62 versus 64 years, P = 0.64), relapse rate (48% versus 37%, P = 0.27), estimated median time to progression (43 versus 65 months, P = 0.14), monoclonal gammopathy (50% versus 44%, P = 0.63), t(14;18) involving IGH/MALT 1 (11% versus 8%, P = 0.68), trisomy 3 (31% versus 27%, P = 0.69), trisomy 18 (8% versus 10%, P = 0.74) and the presence of autoimmune diseases between both groups (53% versus 37%, P = 0.09).

CONCLUSION

In conclusion, we found that PCD is predominantly found in extragastric MALT lymphoma but has no significant impact on clinical course and prognosis.

Primary mucosa-associated lymphoid tissue lymphoma of hypopharynx

Mucosa-associated lymphoid tissue lymphomas are low-grade B-cell lymphomas that arise from a number of extranodal sites, including both nonmucosal and mucosal organs such as the hypopharynx. We reported a patient with a primary hypopharynx mucosa-associated lymphoid tissue lymphoma presenting with a swallowing dysfunction and severe throat pain. The clinical, radiologic, and histopathologic findings are presented. The patient was followed up for 5 years and treated with nonspecific antibiotics, chemotherapy, and radiation therapy. Because of prevertebral fascia invasion at the initial presentation, surgical treatment was not preferred. The last biopsies of the hypopharynx revealed no evidence of lymphoid infiltrate. Mucosa-associated lymphoid tissue lymphoma involving the hypopharynx is rare and there is no consensus on its treatment. The treatment protocol is presented and the relevant literature is reviewed.

Therapy of gastric mucosa associated lymphoid tissue lymphoma

Gastric mucosa associated lymphoid tissue (MALT) lymphoma has recently been incorporated into the World Health Organization (WHO) lymphoma classification, termed as extranodal marginal zone B-cell lymphoma of MALT-type. In about 90% of cases this lymphoma is associated with H pylori infection which has been clearly shown to play a causative role in lymphomagenesis. Although much knowledge has been gained in defining the clinical features, natural history, pathology, and molecular genetics of the disease in the last decade, the optimal treatment approach for gastric MALT lymphomas, especially locally advanced cases, is still evolving. In this review we focus on data for the therapeutic, stage dependent management of gastric MALT lymphoma. Hence, the role of eradication therapy, surgery, chemotherapy and radiotherapy is critically analyzed. Based on these data, we suggest a therapeutic algorithm that might help to better stratify patients for optimal treatment success.

Diagnosis and Classification of Malignant Lymphoma and Related Entities in the Bone Marrow Trephine Biopsy

The trephine bone marrow (BM) biopsy is an important diagnostic tool in patients with malignant lymphoma. BM examination can serve to establish or confirm a primary diagnosis of lymphoma or to determine the extent of disease dissemination for staging purposes. BM histology renders information which cannot be gained equally from aspirate material, such as spacial distribution and extent of infiltrates, BM cellularity and fibrosis. Furthermore, cytology including flow cytometric immunophenotyping can give false-negative results in BM involvement by lymphoma due to intralesional fibrosis. In addition to morphological examination, the availability of a broad panel of antibodies suitable for paraffin-embedded tissues, in conjunction with less damaging decalcification procedures, nowadays enables us to perform complete immunophenotyping on BM trephines and allows for classification of lymphoma infiltrates according to established algorithms. Molecular determination of clonality and interphase fluorescent in situ hybridization can be employed selectively to resolve difficult cases. This review describes important diagnostic features of malignant lymphoma in the BM, relevant differential diagnoses, and the proper use of ancillary techniques.

MALT lymphoma in patients with autoimmune diseases: a comparative analysis of characteristics and clinical course

MALT lymphoma, especially of extragastric origin, is thought to be associated with an underlying autoimmune disease (AD) in a significant proportion of patients. No systematic assessment of the clinical characteristics of MALT lymphoma arising in AD as opposed to patients without AD has been performed so far. Therefore, all patients diagnosed and treated for MALT lymphoma at our institution have prospectively undergone routine clinical and serological assessment for AD since 1997. In total, 158 patients were available for analysis, and 61 out of 158 patients (39%) were diagnosed with an underlying AD. Patients with AD were predominantly women and significantly younger at lymphoma diagnosis (56 versus 67 years, P=0.004), with a significantly higher rate of extragastric lymphomas (P=0.012). Furthermore, lymphomas in these patients showed a lower frequency of trisomy 3 (P=0.04) and a significantly lower response rate to Helicobacter pylori eradication therapy in the case of gastric lymphomas (P=0.03). All other parameters including estimated median time to relapse were comparable between both groups. Our data suggest that patients with AD develop MALT lymphoma significantly earlier in life. The clinical course, however, does not appear to be adversely influenced by the presence of AD, as neither rate of relapse nor times to relapse or survival are significantly different.

Asymptomatic conjunctival mucosa-associated lymphoid tissue-type lymphoma with presumed intraocular involvement

PURPOSE

To report a case of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma with presumed intraocular involvement.

METHODS

Observational case report.

RESULTS

A 73-year-old white man presented for a routine eye examination and was found to have a salmon-colored bulbar conjunctival mass of the left eye. Ultrasound showed a low-reflective mass with diffuse thickening of the ciliary body and choroid. Immunohistochemistry and flow cytometry of an incisional biopsy specimen suggested a polyclonal lesion. Treatment with topical steroids yielded no clinical improvement, and excisional biopsy was performed. A diagnosis of MALT lymphoma was made after polymerase chain reaction (PCR) analysis of the immunoglobulin heavy chain (IgH) locus revealed a clonal B-cell population.

CONCLUSIONS

Conjunctival MALT lymphoma can present without symptoms and can extend intraocularly. PCR analysis of the IgH locus can identify lesion clonality when immunohistochemistry and flow cytometry fail to do so.

[Malt lung lymphoma]

MALT lung lymphoma is a low-grade primarily B-cell lymphoma. Most cases develop in a pain free patient presenting a chronic alveolar opacity. In this review, we describe the clinical radiological and pathological features as well as the diagnostic approach to this pathological entity. Prognosis is excellent. Therapeutic options are discussed.

Helicobacter pylori eradication for low-grade gastric mucosa-associated lymphoid tissue lymphoma is more successful in inducing remission in distal compared to proximal disease

A series of studies has shown that Helicobacter pylori eradication induces remission in most patients with low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, there have been few reports about the effect of bacterial treatment on the gastric MALT lymphoma in Korea, a well-known H. pylori endemic area. A total of 111 H. pylori-infected patients were prospectively enrolled in Seoul National University Hospital and 99 among them were completely followed up according to our protocol. After H. pylori eradication, tumoural response was evaluated by endoscopy and histopathology every 2–3 months till complete remission (CR) and every 6 months after achieving CR. Median follow-up period was 41 months (range, 11–125 months). Helicobacter pylori was successfully eradicated in all 99 patients and CR was obtained in 84 (84.8%) of 99 patients. The median time to reach CR was 3 months and 94% of CR is in continuous complete remission. Five patients with CR relapsed after 10–22 months without the evidence of H. pylori reinfection. Cumulative recurrence rate was 2.3, 7.7 and 9.3% at 1, 2 and 3 years, respectively. Tumours were mainly located in distal stomach (67.7%) and tumours in distal stomach were associated with more favourable response than those in proximal stomach (P=0.001). Majority of patients with low-grade gastric MALT lymphoma treated by exclusive H. pylori eradication have a favourable long-term outcome, offering a real chance of cure. Tumour location could be a predictive factor for remission following H. pylori eradication.

Primary gastrointestinal tract lymphoma: diagnosis and management of common neoplasms

Primary gastrointestinal lymphoma represents the most common location of extranodal lymphoma. With the bulk of disease manifesting within the gastrointestinal tract and contiguous lymph nodes, many of the lymphomas occurring in the peripheral lymph nodes can also present with primary gastrointestinal tract involvement. Molecular biology has recently enabled significant progress in the diagnosis and management of primary gastrointestinal lymphoma. Herein, we will discuss the major lymphomas affecting the bowel and highlight their key morphological, immunophenotypical and molecular diagnostic attributes. Similarly, in keeping with recent therapeutic advances, we will briefly discuss some important treatment considerations. Thus, this review is intended to offer clinicians and pathologists an overview of primary gastrointestinal lymphomas.

Helicobacter pylori eradication in gastric mucosa-associated lymphoid tissue lymphoma: Results of a 196-patient series

Prospective studies have reported ongoing remissions in most patients with localized Helicobacter pylori-positive gastric mucosa-associated lymphoid tissue lymphoma after curing the infection. Using specific selection criteria, the outcome of 196 patients treated in routine clinical practice was analysed. Complete remission rates, stability of remissions and frequency of relapse and histologic residual disease were in accordance with previous prospective clinical trials, whereas the median age was higher. Only a minority had a complete staging, and it may be expected that there is a significant group of patients with an unrecognized higher stage in this cohort. The frequency of follow-up investigations was also not considered as recommended in a considerable number of patients. Nevertheless, the outcome of patients was favourable regardless of limited staging and follow-up procedures. Amended recommendations and special guidelines for elderly and patients with concomitant disease should be considered.

Role of Helicobacter pylori in conjunctival mucosa-associated lymphoid tissue lymphoma

OBJECTIVE

Conjunctiva-associated lymphoid tissue is the conjunctival equivalent to mucosa-associated lymphoid tissue (MALT). Mucosa-associated lymphoid tissue lymphoma has been shown to be associated with Helicobacter pylori. In this study, the prevalence and possible role of H. pylori infection in conjunctival MALT lymphoma were evaluated.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Thirteen cases of conjunctival MALT lymphoma were investigated. Five samples of conjunctival lymphoid hyperplasia and 20 biopsies of normal conjunctiva served as controls.

METHODS

The specimens were investigated for the presence of H. pylori with immunohistochemistry (IHC) and nested polymerase chain reaction (PCR) techniques. For each case of conjunctival MALT lymphoma, information regarding gender, age at presentation, conjunctival localization, and information of generalized MALT lymphoma were collected.

MAIN OUTCOME MEASURES

Detection of H. pylori and patient characteristics.

RESULTS

The 13 conjunctival MALT lymphomas originated from 8 women and 5 men with an average age of 62 years (range, 25-87). Only 1 patient had evidence of systemic MALT lymphoma. H. pylori could not be identified in any of the conjunctival MALT lymphomas, in conjunctival lymphoid hyperplasia, or in normal conjunctival biopsies using IHC and PCR techniques.

CONCLUSIONS

An association between H. pylori and localized conjunctival MALT lymphoma could not be verified. Antigens other than H. pylori may take part in the development of conjunctival MALT lymphoma.

MALT lymphoma associated genetic aberrations occur at different frequencies in primary and secondary intestinal MALT lymphomas

BACKGROUND AND AIMS

Limited data are available on intestinal MALT lymphoma owing to its relatively rare occurrence. The frequency of associated genetic changes was therefore analysed in intestinal MALT lymphoma to determine whether primary and secondary examples may be distinguished by their genetic profile.

METHODS

Patients diagnosed with MALT lymphoma involving the intestine were evaluated and compared with 71 cases with localised gastric MALT lymphoma. Paraffin embedded samples were evaluated for t(11;18)(q21;q21) by reverse transcription polymerase chain reaction, and by fluorescence in situ hybridisation for t(14;18)(q32;q21), t(1;14)(p22;q32), and trisomies 3 and 18.

RESULTS

30 consecutive patients with MALT lymphoma involving the intestine were identified: 16 had primary intestinal lymphoma and 14 had secondary MALT lymphoma. t(11;18)(q21;q21) was found in one third of the patients, but there was a significant difference between the secondary MALT lymphomas and the primary intestinal and gastric MALT lymphoma groups (57% v 12.5%, p = 0.019, and 57% v 24%, p = 0.022). Two patients with primary intestinal MALT lymphomas were positive for t(1;14)(p22;q32) and none was positive for t(14;18)(q32;q21). Primary intestinal MALT lymphoma had a significantly higher frequency of trisomies 3 or 18 (81% v 36%, p = 0.024; 81% v 14%, p<0.001), in contrast to secondary intestinal MALT lymphomas and localised gastric MALT lymphomas.

CONCLUSIONS

The genetic profile of primary intestinal MALT lymphomas appears to be different from that of secondary intestinal or local gastric MALT lymphomas. Because of the high prevalence of trisomy 3 or 18, or both, in primary intestinal lymphoma, these numerical aberrations might be regarded as a genetic hallmark of the disease.

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

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is the third most common non-Hodgkin lymphoma subtype, accounting for around 6-8% of all non-Hodgkin lymphomas in the Western hemisphere. Although MALT lymphomas are clinically indolent, the disease is typically chronic, requiring long-term clinical surveillance and, often, repeated biopsies. Pathologists thus play a central role in the diagnosis and management of these patients. The optimal diagnosis and management of a MALT lymphoma requires careful integration of morphological, immunohistochemical and molecular information, together with close cooperation with the clinician treating the patient. This review discusses recent developments in the molecular pathogenesis of MALT lymphoma and provides strategies for integrating this information into daily pathological practice.

Assessment of Disease Dissemination in Gastric Compared With Extragastric Mucosa-Associated Lymphoid Tissue Lymphoma Using Extensive Staging: A Single-Center Experience

Purpose

Molecular data and preliminary clinical findings have suggested mucosa-associated lymphoid tissue (MALT) lymphoma as a multifocal disease in a high percentage of patients. We report our findings with an extensive staging routine applied in patients diagnosed with MALT lymphoma at our institution.

Patients and Methods

A total of 140 consecutive patients (61 with gastric and 79 with extragastric MALT lymphoma) underwent staging according to a standardized protocol. Staging included gastroscopy with multiple biopsies, endosonography of the upper GI tract, computed tomography of thorax and abdomen, lymph node sonography, colonoscopy with multiple biopsies, otorhinolaryngologic assessment, magnetic resonance imaging of salivary and lacrimal glands, and bone marrow biopsy. All lesions suggestive of lymphoma involvement were subjected to biopsy, if accessible, and biopsies were evaluated for MALT lymphoma–specific genetic aberrations by means of reverse transcriptase polymerase chain reaction and/or fluorescent in situ hybridization.

Results

Fifteen (25%) of 61 patients with gastric MALT lymphoma had multiorgan involvement, with dissemination beyond the GI tract in six patients. By contrast, significantly more patients with extragastric MALT lymphoma had dissemination to another MALT organ (37 of 79 patients, 46%; P = .045). Nine of these 37 patients had dissemination to the stomach. Only three (2%) of 140 patients had bone marrow involvement. Multifocality was significantly associated with t(11;18)(q21;q21) in gastric lymphomas (P = .045) and with trisomy 18 in extragastric lymphomas (P = .011).

Conclusion

Our findings suggest that MALT lymphoma frequently presents as a multifocal disease. Extragastric MALT lymphomas are significantly more prone to dissemination than gastric MALT lymphomas.

[MALT (Mucosal Associated Lymphoid Tissue) lymphoma of the palpebral conjunctiva]

BACKGROUND

MALT (Mucosal Associated Lymphoid Tissue) lymphomas of the conjunctiva belong to the extranodal marginal zone B-cell lymphomas. This site, while standard, is uncommon.

CASE-REPORT

A pink papular tumor developed on the lower eyelid of a 59-year-old woman. Sarcoidosis was diagnosed 9 years earlier associated with mediastinal lymphadenopathy and erythema nodosum not requiring treatment. Histological examination yielded a diagnosis of conjunctival MALT lymphoma. No visceral involvement was demonstrated. Radiotherapy (30 Gy) induced a complete response. A remote lesion developed on the patient's arm 18 months later. No other sites were found. Further radiotherapy (26 Gy) again induced complete remission. No new lesions were seen after 24 months of follow-up.

DISCUSSION

This case is interesting because of the association of a MALT lymphoma and previous sarcoidosis, described in the literature as "sarcoidosis-lymphoma syndrome". Association of sarcoidosis with MALT lymphoma is infrequent. Treatment of conjunctival MALT lymphoma is standardized. Radiotherapy offers excellent efficacy and is well tolerated at this site. Regular and long-term follow-up is required. Local and distant relapse can occur.

Antibiotic treatment is not effective in patients infected with Helicobacter pylori suffering from extragastric MALT lymphoma

PURPOSE

Apart from anecdotal reports implicating Helicobacter pylori (HP) in the development of extragastric mucosa associated lymphoid tissue (MALT) lymphoma, no large scale prospective studies have been performed on this topic.

PATIENTS AND METHODS

A total of 77 patients with extragastric MALT lymphoma were prospectively studied. The presence or absence of HP was tested by histology, urease breath test, and serology. Patients were also tested for hepatitis A, B, and C and autoimmune conditions along with assessment of MALT lymphoma-specific genetic changes.

RESULTS

Evidence for infection with HP was present in 35 of 77 patients (45%), and three of 75 patients tested (4%) were positive for hepatitis C and one for hepatitis B. All patients with HP-infection underwent eradication, 16 before initiation of further therapy. Apart from one patient with lymphoma involving parotid and colon, who achieved regression of the colonic lesions, none of these 16 patients showed regression of the lymphoma after a median follow-up of 14 months (range, 8 to 48+ months) before initiation of definitive treatment. No correlation between HP-status, localization, stage, autoimmune diseases, and genetic findings was seen.

CONCLUSION

In our series, HP-eradication was ineffective for treatment of extragastric MALT lymphomas. This finding, along with an infection rate of 45%-as could also be expected in the general Austrian population-suggests that HP does not play a role in the development of these lymphomas. Antibiotic treatment targeting HP should, therefore, be discouraged in patients with extragastric MALT lymphomas.

Infectious agents in mucosa-associated lymphoid tissue-type lymphomas: pathogenic role and therapeutic perspectives

Mucosa-associated lymphoid tissue (MALT) lymphoma probably constitutes the best in vivo model showing how complex interplay between B lymphocytes and the surrounding microenvironment may lead to a neoplastic disorder. After the seminal discovery of the pathogenic association between Helicobacter pylori and gastric MALT lymphomas, evidence suggests the possible involvement of other infectious agents in the development of MALT lymphomas arising at different body sites. Although several other bacteria (Borrelia burgdorferi, Campylobacter jejuni, and Chlamydia psittaci) and viruses (Hepatitis C virus) seem to play a role in lymphomas presenting at different locations, a possible common pathogenic mechanism is emerging. Several lines of evidence suggest that different infectious agents might provide a chronic antigenic stimulation that elicits host immune responses able to promote clonal B-cell expansion. This model is also substantiated by the increasing number of patients with MALT lymphomas who exhibit objective clinical responses after antimicrobial therapy. A multidisciplinary approach is critical to better understand the complex etiopathogenesis of MALT lymphomas with the final goal to dissect the clinicopathologic heterogeneity of these disorders and design more tailored preventive and therapeutic approaches.

Nongastric Marginal‐Zone B‐Cell MALT Lymphoma: Prognostic Value of Disease Dissemination

The aim of this study is to describe the clinical features and define the prognostic significance of disease dissemination in a large series of nongastric marginal-zone B-cell mucosa-associated lymphoid tissue (MALT) lymphomas. We studied 208 patients with nongastric marginal-zone B-cell MALT lymphoma diagnosed and treated from 1991 to 2004. Ninety percent of the patients had a single site of MALT involvement--skin (26%), salivary glands (18%), orbit (14%), Waldeyer's ring (13%)--and 39% and 28% had nodal involvement and bone marrow involvement, respectively. After a median follow-up of 2.7 years, the median event-free survival (EFS) time was 2.4 years, and the median overall survival (OS) time was not reached. On univariate analysis, the features significantly associated with longer EFS and OS times were the following: single MALT site involvement (OS), localized disease (EFS and OS), no nodal disease (EFS and OS), skin and orbit lymphoma (OS), and stage IV disease without bone marrow involvement (OS). On multivariate analysis, both bone marrow and nodal involvement were associated with shorter OS. This study describes the clinical features and the natural history of nongastric marginal-zone lymphomas and highlights that the dissemination to lymph nodes and bone marrow is associated with a poorer outcome.

[Mucosa-associated lymphoid tissue lymphoma of the lacrymal gland--a case report]

Mucosa-associated lymphoid tissue (MALT) lymphoma has drawn attention in the last twenty years due to its pathological and clinical characteristics. It is a question of B-cell neoplasm with extranodal origin, and with invariable prolonged localisation, indicating indolent malignancy. It is believed that this type of lymphoproliferative neoplasm is triggered by chronic antigenic stimulation. This is supported by the observation that this type of extranodal lymphoma is frequently found in regions affected by chronic inflammation, such as mucosa of the stomach, the respiratory tract, as well as of the salivary and the thyroid glands. It is not common in the breasts, liver, kidneys, and gallbladder. Primary orbital lymphomas account for 5-14% of all extranodal lymphomas. The most commonly involved orbital tissue structures are: conjunctiva, the eyelids, and retrobulbar tissue, while the development of the disease in the lachrymal gland is extremely rare. No wonder that the literature on the presentation, treatment modalities, and recommendations for the monitoring of MALT lymphoma of the lachrymal gland is so scarce. Given the aforementioned facts, the case report of a patient with primary localisation of MALT lymphoma of the lachrymal gland was considered intriguing; initially, the patient was successfully treated by surgical intervention followed by radiation therapy (TD 30 Gy).

Phase II study of oxaliplatin for treatment of patients with mucosa-associated lymphoid tissue lymphoma

PURPOSE

Various chemotherapeutic regimens have been applied for treatment of mucosa-associated lymphoid tissue (MALT) lymphoma, but no standard regimen has been identified to date. In view of the activity of oxaliplatin (L-OHP) in various types of lymphoma, we performed a phase II study to evaluate the activity of L-OHP for treatment of MALT lymphoma. The primary objective of this study was to determine the objective response rate according to WHO standard criteria.

PATIENTS AND METHODS

A total of 16 patients with MALT lymphoma of various sites of origin (four of the ocular adnexa, five of the salivary glands, three of the stomach, two of the lung, and one of the colon and the breast) were administered L-OHP at a dose of 130 mg/m2 infused during 2 hours every 3 weeks. Restaging was performed every two cycles; treatment was continued until complete remission (CR) or for a maximum of six cycles in responders.

RESULTS

Sixty-five cycles were administered (median, four; range, two to six); toxicity consisted of transient sensory neuropathy in eight patients and nausea/emesis WHO grade 2 in two patients, whereas hematologic adverse effects (thrombocytopenia and leukocytopenia grade 2) occurred in only one patient each. Fifteen patients responded to chemotherapy, with nine achieving CR (56%), six (37.5%) achieving partial response, and one achieving stable disease; the median time to response was 4 months (range; 2 to 4 months).

CONCLUSION

These data suggest L-OHP is a highly active agent for treatment of MALT lymphoma. However, a longer follow-up is needed to judge whether these remissions are durable.

Marginal zone lymphoma of the lacrimal gland spreading to the lung and the bone marrow 11 years after first symptoms

We report on the case of a 52-year-old male presenting with an extranodal marginal zone lymphoma of the mucosa-associated tissue (MALT lymphoma) in the lung 11 years after radiotherapy for a MALT lymphoma of the lacrimal gland, which was primarily diagnosed as dacryoadenitis. Both tumors were investigated by immunohistochemistry and molecular techniques demonstrating their clonal genetic relationship. Both harbored the t(14;18)(q32;q21) and a trisomy 3 and showed identical immunoglobulin heavy-chain gene rearrangements. At the time of pulmonary relapse, clonal CD20- and CD43-positive bone marrow B lymphocytes were detected as well. The elaboration of this case emphasizes the importance of the combined use of modern diagnostic methods for establishment of correct diagnosis of MALT lymphomas at late relapses, which is essential for proper patient management.

Ocular adnexal marginal zone B cell lymphoma: a clinical and pathologic study of 23 cases

To better characterize ocular adnexal marginal zone lymphoma of mucosa-associated lymphoid tissue (MZL-MALT), we analyzed the clinical and pathologic features of 23 patients (11 men, 12 women, median age 66 years). The tumor was confined to one ocular structure in 18 cases (conjunctiva, n=8; orbit, n=8; or lacrimal gland, n=2). Concurrent extraorbital disease was detected by the staging procedure in five patients, and preferentially involved other MALT sites. Histogenetic B cell marker studies, available in 13 cases, showed an early post-germinal center (GC) phenotype (BCL-6(-)/IRF4(+)/CD138(-)) (n=5) or a late post-GC phenotype (BCL-6(-)/IRF4(+)/CD138(+)) (n=8), which could be helpful for discrimination from other types of small-B cell lymphoma. BCL10 was positive in 12 of 13 patients tested, with nuclear (n=4) or cytoplasmic (n=8) immunoreactivity. These staining patterns ruled out t(1;14)(p22;q32) translocation. T(11;18)(q21;q21), another MZL-MALT-specific translocation, was detected by reverse transcriptase polymerase chain reaction in four of 15 patients tested. Clinical outcome was excellent but the overall relapse rate was 26.1% with a median follow-up of 39 months (range 6-132 months). Regardless of the disease stage at diagnosis, combined chemotherapy and radiotherapy seemed to be more effective than chemotherapy alone in ocular adnexal MZL-MALT, as persistent complete remission was achieved in nine patients receiving combination therapy, while six of 14 patients treated with chemotherapy alone relapsed.

Immunohistochemistry in bone marrow pathology: a useful adjunct for morphologic diagnosis

Pathomorphological examination of trephine biopsies of the bone marrow (BM) represents a standard method for the diagnosis and staging of hematologic neoplasms and other disorders involving the BM. The increasing knowledge about the genetic basis and biology of hematologic neoplasms, as well as the recently proposed WHO classification system, provide the framework for an accurate diagnosis. Although conventional morphology remains the gold standard for paraffin-embedded BM trephines, immunohistochemical stainings have become an integral part of the diagnostic workup. Antibodies suitable for paraffin sections are generally applicable to BM trephines, but modifications of staining protocols may be necessary due to the alternative fixatives and decalcification procedures used for BM biopsies. The indications for immunostainings range from confirmation and classification of lymphoma involvement, subclassification of acute leukemias, and estimating blast counts in myelodysplastic and myeloproliferative syndromes to characterization of BM involvement in nonhematologic neoplasms. Although subtyping of NHL in the BM is more difficult from the point of morphology, classification of the entities that frequently involve the BM, especially the small B-cell lymphomas, can easily be achieved with the help of immunohistochemistry. In this review, we try to summarize the current state of the art in BM immunohistochemistry for the diagnosis of hematologic disorders. Moreover, diagnostic algorithms and useful antibody panels are proposed for a rational and cost-effective approach.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma of the lung

Non-Hodgkin's lymphoma very rarely involves the esophagus, occurring in less than 1% of patients with gastrointestinal lymphoma. A few cases of mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus have been reported in the English literature. To our knowledge, there has been no report of MALT lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma (BALT) of the lung. This report details the radiological and clinical findings of this first concurrent case.

High relapse rate in patients with MALT lymphoma warrants lifelong follow-up

BACKGROUND

B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) is thought to be an indolent disease, with a good prognosis following various forms of treatment. Little, however, is known about the rate and pattern of relapse following successful treatment.

PATIENTS AND METHODS

We have analyzed time to and pattern of relapse in patients with MALT lymphoma, along with investigation of t(11;18)(q21;q21), t(1;14)(p22;q32), and t(14;18)(q32;q21) involving IGH/MALT1, trisomy 3, and trisomy 18. Eighty-six patients achieving complete remission (CR) after initial therapy with sufficient follow-up data were available. Primary site of disease was the stomach (n = 36), salivary gland (n = 19), ocular adnexa/orbit (n = 12), lung (n = 8), thyroid (n = 5), breast (n = 3), liver (n = 2), and skin (n = 1).

RESULTS

Thirty-two patients (37%) relapsed between 14 and 307 months (median 47 months) after initial CR. Ten relapses were local, whereas the remaining patients relapsed in a distant organ. Eight of 36 gastric versus 24 of 50 nongastric MALT lymphomas (P = 0.02) relapsed. Five patients had a second recurrence 26 to 56 months after a second CR. Relapse rates were not related to forms of initial treatment. Chromosomal aberrations were detected in 14 of 28 (50%) relapsing patients, and chromosomal alterations were identical at diagnosis and relapse. No significant association of any of the genetic changes investigated with relapse was found. Interestingly, patients with t(11;18)(q21;q21) had a significantly longer median time to relapse (76 months) than patients without this translocation (29 months; P = 0.012).

CONCLUSIONS

In view of the late relapses seen in our series, lifelong observation of all patients treated for MALT lymphoma seems to be required.

Bilateral cystic parotid masses and a hypopharyngeal mass: a case report and review of mucosa-associated lymphoid tissue lymphoma in the head and neck

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade B-cell lymphoma that was first described in gastric mucosa. Although presentation in the parotid gland is not unusual, bilateral cystic masses and associated hypopharyngeal involvement are rare. We describe an 83-year-old man with a large painless facial swelling; he was otherwise asymptomatic. On examination, bilateral parotid masses and a mass in the hypopharynx were found. Biopsy of the hypopharynx was consistent with MALT lymphoma. The patient was treated with single-agent chemotherapy and had a good initial response. MALT lymphoma occasionally originates within the salivary glands and other sites in the head and neck region. This disease should be considered in the differential diagnosis of cystic or bilateral parotid masses and hypopharyngeal masses.

FDG-PET scanning for detection and staging of extranodal marginal zone lymphomas of the MALT type: a report of 42 cases

BACKGROUND

Although reports have suggested that FDG-PET scans were not useful for staging of extranodal marginal zone lymphomas (MZL), experience at our center suggests otherwise. Thus we reviewed the findings of FDG-PET scans in patients with extranodal MZL seen at our center.

PATIENTS AND METHODS

A database of 175 patients with histologically-confirmed diagnoses of extranodal MZL was reviewed. Forty-two patients who had had FDG-PET scans for initial staging were identified. All information was obtained by retrospective review of medical records and PET scans.

RESULTS

Thirty-four (81%) patients had focal tracer uptake within verified tumor sites, six (14%) patients did not, and two (5%) patients had indeterminate uptake. Seven of the 34 (21%) patients with uptake within verified tumor sites had uptake in regional lymph nodes and four patients were upstaged due to FDG-PET findings. Eight patients also obtained post-treatment FDG-PET scans. In five of those eight, the repeated FDG-PET scan indicated a complete response, and in three there was an indeterminate or mixed response.

CONCLUSION

FDG-PET scans carried out for initial staging of extranodal MZL detected disease in a high proportion of patients. This study suggests that imaging with FDG-PET scans is useful for both initial staging and follow-up of patients with extranodal MZL.

Malignant and benign lymphoid lesions of the lung

Lymphoid lesions of the lung produce a complex of problems for the practicing pathologist. Although these lesions are eventually referred to hematopathologists, it is still the general surgical pathologist who first encounters them and confronts the problem of formulating an initial diagnosis. Over the last 20 years there has been a revolution in our knowledge of the classification and natural history of the pulmonary lesions, a plethora of information which warrants a thorough review. The purpose of this discussion is to report the clinical features and courses, pathologic features and, when known, etiologies or pathogenesis of the major "primary" pulmonary lymphoid lesions and present a brief approach to differential diagnosis. I will divide the lesions into malignant and benign, discussing each in turn.

Variable frequencies of MALT lymphoma-associated genetic aberrations in MALT lymphomas of different sites

Although several recurrent genetic aberrations are known to occur in MALT lymphoma, no comprehensive study on the most prevalent MALT lymphoma-associated genetic aberrations is available. We therefore screened 252 primary MALT lymphomas for translocations t(11;18)(q21;q21), t(14;18)(q32;q21), and t(1;14)(p22;q32), and trisomies 3 and 18. The above-listed translocations occurred mutually exclusively and were detected overall in 13.5, 10.8, and 1.6% of the cases; trisomy 3 and/or 18 occurred in 42.1%. The frequency at which the translocations occurred varied markedly with the primary site of disease. The t(11;18)(q21;q21) was mainly detected in pulmonary and gastric tumors, whereas the t(14;18)(q32;q21) was most commonly found in lesions of the ocular adnexa/orbit, skin, and salivary glands. Trisomies 3 and 18 each occurred most frequently in intestinal and salivary gland MALT lymphomas. Our results demonstrate that the three translocations and trisomies 3 and 18 occur at markedly variable frequencies in MALT lymphoma of different sites.

Bronchial-associated lymphoid tissue lymphoma: a clinical study of a rare disease

Bronchial-associated lymphoid tissue (BALT) lymphoma is a distinct subgroup of low-grade B-cell extranodal non-Hodgkin's lymphoma, classified as marginal-zone lymphoma. This study was performed in order to assess the natural history of this rare entity. We evaluated retrospectively the clinical data of 22 patients with biopsy-proven BALT lymphoma at two tertiary-care institutions from 1996 to 2002. Immunophenotyping was done to confirm the abnormal populations of B-lymphoid cells in all cases, and clonality was determined by flow cytometry or molecular studies. There were 11 men and 11 women in the sample, median age 61 years (range 21-80 years); nine were asymptomatic at diagnosis. All 13 symptomatic patients had non-specific pulmonary complaints. On computed tomographic examination of the chest, 11 patients had bilateral disease, 12 had lung nodules, and 10 had a mass or air-space consolidation. In all but one case the disease was localised to the lung at diagnosis and none had peripheral blood or bone marrow involvement. Out of 22 patients, 20 received treatment in various combinations, 12 had chemotherapy and/or rituximab, six had surgery, and two received radiation therapy as primary treatment. A complete response (CR) was achieved in nine patients and a partial response was obtained in 10 patients. Seven of 10 patients who had unilateral disease achieved a CR. The estimated progression-free survival was 53 months. All patients were alive during the median follow-up period of 36 months (range 12-76 months). It appears that BALT lymphoma tends to be localised to lung at the time of diagnosis, responds well to local or systemic therapy, and has a favourable prognosis.

Extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue?type of the orbit and ocular adnexa

Non-Hodgkin's lymphomas of the orbit and ocular adnexa (OOA), the majority of which are extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue-type (MALT lymphomas), are a rare disorder. The aim of this study was to evaluate the clinical features and treatment outcomes and complications in patients with MALT lymphoma of OOA. Thirty-seven patients with a histologically verified diagnosis of MALT lymphoma of OOA were included in this retrospective, observational case study. There were 22 (59%) men and 15 (41%) women, with a median age of 44 years (range, 21-80 years). The most common presenting complaint was a slowly growing orbital mass. The stages were IA(E) in 74%, IA(EE) (bilateral involvement) in 18%, IIIA(E) in 6%, and IVA(E) in 3%. None of the patients had an elevated value of LHD or beta(2)-microglobulin. Surgical resection alone was attempted as the sole treatment in two patients, but tumor recurred 19 and 24 months after surgery. Radiotherapy, with a median tumor dose of 3,060 cGy, was administered in 29 patients; all of the patients achieved complete remission, and none of them had severe later complications. Combination chemotherapy alone was employed in three patients with stage IIIA(E) or IVA(E). With a median follow-up duration of 21 months, the 3-year overall survival (OS) rate and event-free survival (EFS) rate were 97% and 86%, respectively. Subgroup analysis of the patients with localized disease, who received radiotherapy as an initial treatment modality, revealed that 3-year OS rate and EFS rate were 100% and 93%, respectively. All disease recurrences were documented histologically as MALT lymphoma. In conclusion complete staging evaluation is needed to select an adequate treatment modality. Radiotherapy alone can produce excellent local control and survival in patients with localized MALT lymphoma of OOA. Systemic chemotherapy should be considered in patients with advanced stages or systemic manifestation.

Sustained Remissions with Long-term Weekly Chlorambucil Maintenance Therapy in Patients with Mucosa-Associated Lymphoid Tissue Lymphoma

Five patients with mucosa-associated lymphoid tissue (MALT) lymphoma (Helicobacter pylori negative) were initially treated with daily chlorambucil (Chl, 0.06-0.08 mg/kg per day) and achieved complete remission (n = 4) or partial remission (n = 1). They were then given long-term weekly Chl as maintenance therapy with good results. One patient came off treatment and has remained in continued remission for 44 months. This simple, low-cost, and convenient approach deserves further evaluation in patients with MALT lymphoma and other indolent and incurable lymphoproliferative disorders.

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with mitoxantrone, chlorambucil and prednisone (MCP)

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively common type of lymphoma arising in various tissues throughout the human body. Currently, there is no standard chemotherapy for advanced stage MALT lymphoma. This has prompted us to retrospectively analyse our experience with the MCP regimen (mitoxantrone, chlorambucil and prednisone) in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with histologically verified MALT lymphoma undergoing chemotherapy with MCP were evaluated retrospectively. The MCP regimen consists of mitoxantrone 8 mg/m(2) intravenously on days 1 and 2, chlorambucil 3 x 3 mg/m(2) per os (p.o.) on days 1-5 and prednisone 25 mg/m(2) p.o. on days 1-5. Information analysed included localisation of the lymphoma, clinical stage, pretreatment, number of chemotherapy cycles administered, toxicity, response to treatment, follow-up time, relapse and survival.

RESULTS

A total of 15 patients (six females and nine males aged between 34 and 88 years) with histologically ascertained MALT lymphoma undergoing treatment with the MCP regimen were identified from our records. Ten patients had extragastric lymphoma, while five patients suffered from gastric MALT lymphoma. All patients were chemotherapy-naïve, while two had been locally irradiated before application of MCP for recurrent disease. A total of 74 cycles was administered to our patients, with a median number of five cycles per patient. Eight (53%) patients achieved complete remission, six (40%) patients partial response and only one (7%) patient had progressive disease. Subjective tolerance was excellent, and toxicities were mainly haematological, including granulocytopenia World Health Organisation grade 3 and 4 in three patients each. In two patients, this was accompanied by single episodes of uncomplicated herpes simplex infection. At the time of analysis, all patients are still alive. No relapses have occurred after a median follow-up time of 16 (range 12-29) months.

CONCLUSIONS

Our data suggest that MCP is an effective and well-tolerated regimen for treatment of patients with MALT lymphoma irrespective of localisation. Judging from our data, MCP also appears to be a feasible regimen in elderly patients.