Non-gastric extra-nodal marginal zone lymphomas–a single centre experience on 76 patients

Primary mucosa-associated lymphoid tissue lymphoma in fallopian tubes: A case report and literature review

RATIONALE

Mucosa-associated lymphoid tissue (MALT) lymphoma accounts for 7%-8% of newly diagnosed lymphomas. The stomach is the most common organ of origin (nearly 50% of MALT lymphomas). Only 2% of MALT lymphomas arise from the female genital tract, and most originated from uterus. We described a rare case of MALT lymphoma primarily arising from the fallopian tube.

PATIENT CONCERNS

A 26-year-old woman was brought into our gynecological clinic because of a history of irregular menstruation. The transvaginal ultrasonography revealed cystic masses in bilateral adnexa and both of them showed rich vasculature. Laboratory tests showed a high level (455.3 U/mL) of cancer antigen-125 (CA-125).

INTERVENTIONS

A laparoscopy was performed.

OUTCOMES

Frozen section of the removed specimen revealed acute and chronic inflammation with abundant inflammatory cells infiltrating the mesenchyme. The right fallopian tube was removed. However, the final histological results showed inflammation accompanied by hyperplasia of lymphoid tissue. Immunohistochemistry staining were consistent with MALT lymphoma. The patient received the second surgery to remove the left fallopian tube and also confirmed the same pathology.

LESSONS

Gynecologists should be aware of cystic masses which showed rich vasculature and high level of CA-125.

Right Middle Lobe Single Pulmonary Opacity With Air Bronchogram: A Problem-Solving Case Report

Marginal zone lymphoma (MZL) is a relatively uncommon subtype of non-Hodgkin lymphoma consisting of extranodal, nodal, and splenic MZL. Mucosa-associated lymphoma constitutes the majority of extranodal MZL including but not limited to the stomach, lung, salivary gland, ocular adnexa, skin, and thyroid. Depending on the site of origin, maltoma may present with different symptoms.

Here we present a patient who presented to the pulmonary clinic for further evaluation of a right middle lobe consolidation. She was treated with a course of antibiotics empirically with no interval change in imaging. She underwent bronchoscopy with biopsy. Pathology was remarkable for extensive lymphoid infiltrates consisting of mixed B and T lymphocytes. Positron emission tomography (PET) CT demonstrated mild uniform uptake in consolidation with no evidence of PET avid distant metastasis. CT-guided biopsy was consistent with extranodal marginal zone lymphoma. She underwent right middle lobectomy with no complications.

As mentioned in our case, bronchoscopy is usually nondiagnostic and a lung biopsy is needed in pulmonary maltoma. Treatment is based on the tumor location and extent of the disease. Prognosis is good with an 86-95% five-year survival.

Risk adapted approach: How to treat splenic marginal zone lymphoma in resource-poor settings? - The real-life experience of a Brazilian cancer treatment center

Background

Splenic marginal zone lymphoma (SMZL) is a rare lymphoid B-cell malignant neoplasm with primary involvement of the spleen. It is a chronic disease, of indolent behavior and prolonged survival. However, 25% of cases have higher biological aggressiveness, propensity for histological transformation to high grade B-cell non-Hodgkin lymphoma and shortened survival. Recognition of these cases of reserved outcome is important for selecting a risk-adapted therapeutic approach in a resource-poor settings.

Methods

We described clinical and epidemiological characteristics, survival analysis and prognostic factors in a retrospective cohort of 39 SMZL patients, treated in Latin America.

Results

We observed a predominance of female (71.8%), median age of 63 years and higher incidence of B symptoms (56.4%) and extra-splenic involvement (87.1%) than in European and North-American series. With a median follow-up of 8.7 years (0.6-20.2 years), estimated 5-year overall survival (OS) and progression-free survival (PFS) were 76.9% and 63.7%, respectively. Factors with adverse prognostic impact on OS and PFS were Hb < 100 g/L, platelet count < 100 x 10⁹/L, albumin < 3.5 g/dL, LDH > 480 U/L and high-risk Arcaini and SMZL/WG scores. Despite a relative low number of patients, no superiority was observed among the therapeutic regimens used including rituximab monotherapy, splenectomy and cytotoxic chemotherapy.

Conclusion

Therefore, in resource-poor settings, where access to immunotherapy is not universal for all SMZL patients, we suggest that first-line should consist on rituximab therapy for elderly patients or with high surgical risk or with at least 1 risk factor identified in our study. Remainders can be safely managed with splenectomy.

A Unique Case of Primary Extranodal Marginal Zone Lymphoma of the Anal Canal

Marginal zone lymphomas represent approximately 10-12% of all B-cell lymphomas. Extranodal marginal zone lymphomas (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphomas are the most common subtype. Almost half of all MALT lymphomas arise in the gastrointestinal (GI) tract and, while the stomach is the most common site of GI involvement, the small and large intestines can also be involved. Rare cases of MALT lymphoma involving the rectum have been reported; however, to our knowledge, involvement of the anal canal has never been reported in the literature. Here, we describe a unique case of MALT lymphoma of the anal canal. Infectious agents have been implicated in the pathogenesis of MALT lymphomas, possibly through persistent antigenic stimulation of the area; however, in our case no such infection was documented.

Primary extranodal lymphoma of the glands. Literature review and options for best practice in 2019

Primary extranodal non-Hodgkin's lymphomas (EN-NHL) are a heterogeneous group of malignancies that involve numerous entities with significant difference in terms of tumor site locations, prognostic factors, biology expression, and therapeutic options. In the literature, many EN-NHL types were reported from limited series which only allowed narrow views for elucidating prognostic factors and defining the role of loco-regional therapies in the era of new systemic and biologically targeted therapies. The Rare Cancer Network (RCN), an international multidisciplinary consortium, has published a number of reports on several EN-NHL sites which included many gland locations. In this review, we will focus on the recent literature for a selected number of EN-NHL types in both exocrine and endocrine gland locations. We aim to provide renewed and clear messages for the best practice in 2019 for diagnosis, histopathology, treatments, and also their prognostic implications. We believe that better understanding of molecular and genetic characteristics of these particular diseases is crucial for an appropriate management in the era of personalized treatment developments.

Perforation caused by gastric mucosa associated lymphoid tissue lymphoma: A case report and literature review

RATIONALE

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common and best-studied extranodal marginal zone lymphoma of the MALT. It is characterized by an indolent clinical course and excellent survival compared with other malignant tumor. Complications such as obstruction, perforation or bleeding are rarely observed. The treatment strategy is still controversial.

PATIENT CONCERNS

A 59-year-old man, who had been diagnosed with MALT lymphoma by gastroscopy and biopsy one month before, came to the hospital for a sudden onset of abdominal pain after breakfast.

DIAGNOSES

MALT lymphoma; gastric perforation.

INTERVENTIONS

Emergency surgery.

OUTCOMES

Gastric perforation repair and jejunostomy was performed. The patient recovered well and is preparing for combined chemotherapy.

LESSONS

This case report illustrates the challenges in diagnosis and treatment of MALT lymphoma. We discussed the particularity of its clinical characteristics, treatment strategies and prognosis combined with literature review, and we think that early diagnosis and timely appropriate chemotherapy is of great importance.

Long-term outcome of 487 patients with early-stage extra-nodal marginal zone lymphoma

Background

Localized early-stage extra-nodal marginal zone lymphoma (MZL) presents with heterogeneous organ involvement and is treated with various modalities, including resection, radiotherapy, and systemic therapy. We report the long-term outcome of a large cohort of extra-nodal MZL and assess the impact of patient and disease characteristics, organ site, and treatment strategy on disease control and survival.

Patients and methods

We identified 487 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to Memorial Sloan Kettering Cancer Center. Pathology was reviewed by hematopathologists at our institution. Patient and disease factors as well as treatment types were analyzed for association with relapse-free survival, overall survival, and cumulative incidence of relapse.

Results

Median follow-up after treatment was 4.7 years. Five-year relapse-free survival and overall survival were 60% and 89%, respectively. Cumulative incidence of disease-specific death at 5 years was 1.3%. Radiotherapy alone was the initial treatment in 50% of patients, followed by surgical resection (30%), observation (8%), immunotherapy (4%), and chemotherapy (2%). Initial treatment type, primary disease site, and number of involved sites were significant factors in multivariable analysis of relapse (all P < 0.05). When compared with stomach, MZL originating in other disease sites (HR > 2.0, P ≤ 0.001), except for thyroid, had higher risk of relapse. Strategies such as antibiotics or topical therapies were associated with higher risk of relapse when compared with radiation therapy (P < 0.001). Crude rate of transformation to pathologically confirmed large-cell lymphoma was 2% (11 patients).

Conclusion

Overall and cause-specific survival are high in early-stage extra-nodal MZL. Curative-intent treatment led to fewer relapses and reduced the need for salvage. Stomach cases had lower risk of relapse than other anatomic primary sites. This study supports the use of local therapies to treat stage IE and IIE MZL.

Overview on the management of non-gastric MALT lymphomas

Extranodal marginal zone B-cell lymphomas (EMZLs) of the mucosa-associated lymphoid tissue (MALT) are indolent lymphomas which can present at any extranodal site. The most frequent localizations (other than stomach) are ocular adnexa, salivary gland, skin, lung and thyroid. Chronic inflammation and antigenic stimulation are a potential risk for the development of MALT lymphomas. While Helicobacter Pylori (HP) is known to be associated with gastric MALT lymphoma and antibiotic therapy is effective in the setting of HP-positive, other microorganisms (such as Chlamydophila Psittaci, Campylobacter Jejiuni, Borrelia Burgdoferi) have been implicated in the pathogenesis of non-gastric MALT lymphomas. However, antibiotic therapy has not been extensively investigated for the non-gastric type, except for ocular adnexal MALT lymphoma, which could benefit from an upfront treatment with doxycycline. Surgery, radiotherapy, Rituximab alone or in combination with chemotherapy and "chemo-free" approaches, including lenalidomide, have shown efficacy in the treatment of non-gastric MALT lymphomas.

Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue of the Salivary Glands: A Multicenter, International Experience of 248 Patients (IELSG 41)

BACKGROUND

The salivary gland is one of the most common sites involved by nongastric, extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). A large series of patients with long-term follow-up has not been documented. This multicenter, international study sought to characterize the clinical characteristics, treatment, and natural history of salivary gland MALT lymphoma.

METHODS

Patients with biopsy-confirmed salivary gland MALT lymphoma were identified from multiple international sites. Risk factors, treatment, and long-term outcomes were evaluated.

RESULTS

A total of 247 patients were evaluated; 76% presented with limited-stage disease. There was a history of autoimmune disorder in 41%, with Sjögren disease being the most common (83%). Fifty-seven percent of patients were initially treated with local therapy with surgery, radiation, or both; 37 of patients were treated with systemic therapy initially, with 47% of those receiving rituximab; and 6% of patients were observed. The median overall survival (OS) was 18.3 years. The median progression-free survival (PFS) following primary therapy was 9.3 years. There was no difference in the outcomes between patients receiving local or systemic therapy in first-line management. On multivariate analysis, age <60 years and low to intermediate international prognostic index were associated with improved OS and PFS; Sjögren disease was associated with improved OS.

CONCLUSION

Salivary gland MALT lymphoma has an excellent prognosis regardless of initial treatment, and patients with Sjögren disease have improved survival. Risks for long-term complications must be weighed when determining initial therapy.

Long-term outcomes and patterns of relapse of early-stage extranodal marginal zone lymphoma treated with radiation therapy with curative intent

PURPOSE

To report the long-term outcome and patterns of relapse of a large cohort of marginal zone lymphoma (MZL) patients treated with curative-intent radiation therapy (RT) alone.

PATIENTS AND METHODS

We reviewed the charts of 490 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to our institution. Of those, 244 patients (50%) were treated with RT alone. Pathology was confirmed by hematopathologists at our institution. Patient and disease factors were analyzed for association with relapse-free survival (RFS) and overall survival (OS).

RESULTS

Median age of the cohort was 59 years, and median follow-up was 5.2 years. Ann Arbor stage was IE in 92%. Most common disease sites were stomach (50%), orbit (18%), non-thyroid head-and-neck (8%), skin (8%), and breast (5%). Median RT dose was 30 Gy. Five-year OS and RFS were 92% and 74%, respectively. Cumulative incidence of disease-specific death was just 1.1% by 5 years. Sixty patients (24%) developed relapse of disease; 10 were in the RT field. Crude rate of transformation to pathologically confirmed large-cell lymphoma was 1.6%. On multivariable analysis, primary disease site (P=.007) was independently associated with RFS, along with age (P=.04), presence of B-symptoms (P=.02), and International Prognostic Index risk group (P=.03). All disease sites except for head-and-neck had worse RFS relative to stomach.

CONCLUSION

Overall and cause-specific survival are high in early-stage extra-nodal MZL treated with curative RT alone. In this large cohort of 244 patients, most patients did not experience relapse of MZL after curative RT; when relapses did occur, the majority were in distant sites. Stomach cases were less likely to relapse than other anatomic sites. Transformation to large-cell lymphoma was rare.

Clinical aspects of malt lymphomas

Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma arising in extranodal sites. Several infectious agents and autoimmune disorders have been implicated in its pathogenesis. The stomach represents the most common and best-studied organ involved by MALT lymphoma and its development is strongly associated with Helicobacter pylori (Hp) infection. MALT lymphomas are characterized by an indolent clinical course and excellent survival in most cases, independently of the treatment delivered. Recent progress in the knowledge of the etiology and the cellular and molecular pathological events related to MALT lymphomas allowed us to improve our clinical understanding of this disease entity and to better define treatment strategies.

Extranodal hematopoietic neoplasms and mimics in the head and neck: an update

The head and neck region is a common site for extranodal lymphomas, second only to the gastrointestinal tract; and 12% to 15% of all head and neck tumors are lymphomas. Non-Hodgkin lymphomas are most common, and Hodgkin lymphoma occurs rarely at extranodal sites in the head and neck. Most non-Hodgkin lymphomas of the head and neck region are of B-cell lineage, and the Waldeyer ring is the most common site. Head and neck lymphomas have distinctive epidemiological and clinicopathologic features, including an association with immunosuppression, infectious organisms, or autoimmune disorders; site-specific differences (eg, thyroid gland versus ocular adnexa) for common lymphomas, such as extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue; and genetic differences that provide insights into etiology. Furthermore, the diagnosis of non-Hodgkin lymphomas at extranodal sites implies differences in prognosis and therapeutic implications with lymphomas at nodal sites. In this review, we discuss various types of non-Hodgkin lymphomas and Hodgkin lymphoma, focusing on unique aspects related to the head and neck region. We also discuss a number of newer entities that are clinically indolent as well as mimics of lymphoma that can occur in the head and neck region, including infectious mononucleosis, Kikuchi-Fujimoto disease, Kimura disease, Castleman disease, and immunoglobulin G4-related disease.

Salivary gland lymphoproliferative disorders: a Canadian tertiary center experience

Salivary gland lymphoproliferative disorders (SGLD) are very rare tumors and clinicopathological data is sparse. In a Canadian series of 30 cases, extracted from the surgical pathology files of The Ottawa Hospital between 1990 and 2010, a clinical, histopathological, and immunophenotypic analysis was conducted. Tumors were staged using the Ann Arbor staging and classified using the World Health Organization 2008 classification. There were 15 salivary gland (SG) primary lymphomas with localized disease, predominantly mucosa associated lymphoid tissue type marginal zone lymphoma (MALT-L), but with a significant incidence of low grade follicular lymphoma (FL) and diffuse large B cell phenotype as well. There were 7 systemic SG lymphomas and 5 patients were diagnosed with lymphoproliferative disorders originating from intra-parotid lymph nodes. Finally, the remaining 3 cases represented reactive sialadenitis. A literature review was conducted and our primary lymphoma group was compared to those from other countries. SGLDs are predominantly B cell lymphomas that develop in older adults. Primary tumors, which have MALT-L and low grade FL characteristics, have a favorable survival, however MALT-L have a high rate of relapse. A minority of SG lesions are excised secondary to lymphomas that definitely arose from intra-parotid lymph nodes.

[MALT-type parotid lymphoma--a case report and the review of the literature]

Primary lymphomas of the salivary glands are rare. It is estimated that they constitute no more than 5% of all lymphomas in different locations. The most common subtype developing in parotid glands is marginal zone B-cell mucosa associated lymphoid tissue type lymphoma (MALT) that belongs to a group of low-grade tumours. There are many factors associated with the incidence of that proliferative process: environmental and infectious agents as well as immune deficiency states. We describe a case of primary non-Hodgkin's lymphoma of the parotid gland arising in the background of previously undiagnosed and untreated Sjögren's syndrome in a 52-year-old woman. The article concerns a short review of the literature regarding etiology, symptoms, treatment and survival prognosis in that rare disease as well. MALT lymphomas should always be considered in the differential diagnosis of the tumors and swelling of the parotid gland area. A special, regular monitoring should include all patients with Sjögren's syndrome as those with the proven greater risk of developing that proliferative disease. The role of the laryngologist in the case of MALT-type lymphoma of the parotid gland should focus on a diagnosis and possible tumor cytoreduction with maximal saving of the facial nerve. The essential treatment of this pathology is one of the oncologists and haematologists.

Primary parotid gland lymphoma: a case report

INTRODUCTION

Mucosa associated lymphoid tissue lymphomas are the most common lymphomas of the salivary glands. The benign lymphoepithelial lesion is also a lymphoproliferative disease that develops in the parotid gland. In the present case report, we describe one case of benign lymphoepithelial lesion with a subsequent low transformation to grade mucosa associated lymphoid tissue lymphoma appearing as a cystic mass in the parotid gland.

CASE PRESENTATION

A 78-year-old Caucasian female smoker was referred to our clinic with a non-tender left facial swelling that had been present for approximately three years. The patient underwent resection of the left parotid gland with preservation of the left facial nerve through a preauricular incision. The pathology report was consistent with a low-grade marginal-zone B-cell non-Hodgkin lymphoma (mucosa associated lymphoid tissue lymphoma) following benign lymphoepithelial lesion of the gland.

CONCLUSIONS

Salivary gland mucosa associated lymphoid tissue lymphoma should be considered in the differential diagnosis of cystic or bilateral salivary gland lesions. Parotidectomy is recommended in order to treat the tumor and to ensure histological diagnosis for further follow-up planning. Radiotherapy and chemotherapy should be considered in association with surgery in disseminated forms or after removal.

Primary mucosa-associated lymphoid tissue lymphoma of the salivary glands: a multicenter Rare Cancer Network study

PURPOSE

Involvement of salivary glands with mucosa-associated lymphoid tissue (MALT) lymphoma is rare. This retrospective study was performed to assess the clinical profile, treatment outcome, and prognostic factors of MALT lymphoma of the salivary glands.

METHODS AND MATERIALS

Thirteen member centers of the Rare Cancer Network from 10 countries participated, providing data on 63 patients. The median age was 58 years; 47 patients were female and 16 were male. The parotid glands were involved in 49 cases, submandibular in 15, and minor glands in 3. Multiple glands were involved in 9 patients. Staging was as follows: IE in 34, IIE in 12, IIIE in 2, and IV in 15 patients.

RESULTS

Surgery (S) alone was performed in 9, radiotherapy (RT) alone in 8, and chemotherapy (CT) alone in 4 patients. Forty-one patients received combined modality treatment (S + RT in 23, S + CT in 8, RT + CT in 4, and all three modalities in 6 patients). No active treatment was given in one case. After initial treatment there was no tumor in 57 patients and residual tumor in 5. Tumor progression was observed in 23 (36.5%) (local in 1, other salivary glands in 10, lymph nodes in 11, and elsewhere in 6). Five patients died of disease progression and the other 5 of other causes. The 5-year disease-free survival, disease-specific survival, and overall survival were 54.4%, 93.2%, and 81.7%, respectively. Factors influencing disease-free survival were use of RT, stage, and residual tumor (p < 0.01). Factors influencing disease-specific survival were stage, recurrence, and residual tumor (p < 0.01).

CONCLUSIONS

To our knowledge, this report represents the largest series of MALT lymphomas of the salivary glands published to date. This disease may involve all salivary glands either initially or subsequently in 30% of patients. Recurrences may occur in up to 35% of patients at 5 years; however, survival is not affected. Radiotherapy is the only treatment modality that improves disease-free survival.

Stage IV marginal zone B-cell lymphoma--prognostic factors and the role of rituximab: Consortium for Improving Survival of Lymphoma (CISL) study

Stage IV marginal zone B-cell lymphomas (MZL) are detected in more than 25% of lymphoma patients. In this study, we conducted retrospective analyses of specific cases of stage IV MZL in order to assess their clinical features, as well as the treatments and prognoses of these cases. A total of 94 patients with histological diagnosis of stage IV-MZL from 17 different institutions in Korea were included. Multiple-mucosa-associated lymphoid tissue (MALT)-organs-involved MZL (M-MZL) was detected in 34 patients (36.2%). Bone-marrow-involved stage IV MZL (BM-MZL) was detected in 33 patients (35.1%). Median time to progression (TTP) was 2.4years (95% CI, 1.9-2.9). Five- and 10-year overall survival rates were 84.5% and 79.8%, respectively. Patients with lymph node involvement in stage IV MZL appeared to have worse prognoses in TTP (P=0.015). Thirty-one patients were treated with a regimen including rituximab (CTx-R[+]), and 31 with a regimen that did not include rituximab (CTx-R[-]). The CTx-R(+) group showed better responses than the CTx-R(-) group (83.9%versus 54.8%, P=0.026). However, no differences in TTP duration were detected (P=0.113). Stage IV MZL tend to follow an indolent disease course. Therefore, lymph node involvement is a more valuable prognostic factor for TTP. Rituximab appears to contribute to better responses, but not in cases of TTP.

Multiple mucosa-associated lymphoid tissue organs involving marginal zone B cell lymphoma: organ-specific relationships and the prognostic factors. Consortium for improving survival of lymphoma study

According to a previous review, multiple mucosa-associated lymphoid tissue (MALT)-organs involving marginal zone B cell lymphomas (MZLs) are present in 10-30% of patients. However, the clinical features and specific relationships among involved organs are yet to be clearly identified. In this study, we conducted retrospective analyses of multiple MALT organs involving MZLs (MM-MZLs) to identify their clinical features, treatment, prognosis, and specific relationships among involved organs. For analysis, between June 1987 and June 2009, a total of 55 patients from 17 different institutions in Korea, all of whom were histologically diagnosed with MM-MZL, were included in this study. MM-MZL was defined as MZL involving more than 2 different MALT organs. Multiple involvements within one MALT organ (e.g. both side ocular lesions, multiple lung nodules, and multiple stomach lesions, etc.) were excluded from this study. The male/female ratio of the 55 patients was 41/14. The median age of our subjects was 59 years (range 30-82 years). MM-MZL without lymph node (LN) was detected only in 9 patients (36.2%). Bone marrow (BM) involvement was observed in 17 patients (30.9%). The most common site of involvement was the gastrointestinal (GI) tract (25 patients, 45.5%) followed by the lung (40%), Waldeyer's ring (WR) (27.3%), and ocular area (25.5%). Ocular MZLs were commonly accompanied with WR- or lung-MZLs. GI-MZLs were WR or GI-MZLs. Lung-MZLs were frequently observed with ocular and GI-MZLs. WR-MZLs were ocular or GI-MZLs. A total of 53 patients were treated, and 2 on watchful wait. As much as 48 patients received chemotherapy-based treatment. Among them, CR or PR was achieved in 38 patients (79.2%, 95% CI 67-91%). Median time to progression (TTP) was 2.3 years (95% CI 1.4-3.2 years). Cause-specific overall survival (OS) did not reach the median value. The 5-year OS rate was 84.9%. MM-MZLs tend to be an indolent disease, characterized by prolonged survival with frequent relapses. The majority of cases could be controlled effectively via chemotherapy-based treatment, and prolonged survival was achieved in those patients. The GI, lung, WR, and ocular area were commonly presented with other MALT site MZLs, and an organ-specific relationship appears to be relevant to MM-MZLs.

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.