Non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue

Advances in diagnosis and treatment of gastric MALT lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common extranodal B-cell lymphoma. The incidence of gastric MALT lymphoma has been gradually increasing over the past decade. In recent years, the better understanding of Helicobacter pylori infection has revolutionized the diagnosis and treatment of gastric MALT lymphoma. In this paper, we review the advances in the pathogenesis, diagnosis and treatment of gastric MALT lymphoma.

Clinical, histopathological and immunohistological study of lymphoid disorders in the parotid gland of patients with Sjögren's syndrome

BACKGROUND/AIM

Sjögren's syndrome is a chronic autoimmune systemic disease characterized by polyglandular tissue destruction, leading to keratoconjunctivitis sicca and xerostomia. These patients have 44-fold increased risk of developing salivary gland lymphoma, of which 80% are marginal zone (MALT) type. Having in mind that criteria for distinguishing benign lymphoepithelial lesions from MALT lymphoma are obscure, the aim of this study was to provide practical information that could be integrated into diagnostic practice.

METHODS

Among 32 parotidectomies, 27 cases were identified as having benign lymphoepithelial disorders and 5 cases low grade MALT lymphoma. Histological sections were stained routinely with hematoxylin and eosin (H&E and special stains. Immunohistochemical study was performed by LSAB2 method, by using primary antibodies for CD20, CD3, Kappa and Lambda light chains and Cytokeratin (Dako Denmark).

RESULTS

The 27 patients with Sjögren's sialoadenitis (22 women and 5 men), and 5 patients with MALT lymphoma (only women) were included in this analysis. According to the Ann Harbor Classification, all patients with MALT lymphoma had stage IE. Both groups of patients had an indolent clinical course, except permanent, rapid parotid enlargement in the patients with MALT lymphoma. Histologically, the periductal lymphoid infiltrate, gradually extended to the acini, completely replacing them by a sea of polyclonal lymphocytes, immunoblasts, germinal centers and plasma cells (confirmed immunohistochemically), but sparing the ducts and preserving lobular appearance. The histological feature of salivary gland MALT lymphoma included heterogeneous B-cell infiltrate that totally or subtotally had effaced the normal glandular structure. Malign lymphoepithelial lesions, representing infiltration of the ductal and epithelial structures by monoclonal neoplastic B-cells, positive for CD20, were highlighted by antibody to cytokeratin.

CONCLUSION

The optimal diagnosis of salivary gland MALT lymphoma requires careful integration of clinical, morphological and immunohistochemical results.

More than a third of non-gastric malt lymphomas are disseminated at diagnosis: a single center survey

Mucosa-associated lymphoid tissue (MALT) lymphomas are extranodal B-cell tumors that generally follow an indolent course. The gastrointestinal tract is the most common site of MALT lymphoma, comprising 50% of all cases. The tissue lesions are often localized, have high therapeutic response rates with late relapses with a long overall survival (OS). The patients with non-gastric lesions may follow a different clinical course and many of them present with disseminated disease. This study reports a series of 51 patients with non-gastric MALT lymphoma. Twenty patients (39.2%) presented with disseminated disease, seven (13.7%) patients had two MALT mucosal sites involved and eight (15.7%) had involvement of three or more mucosal sites. At presentation, 17 (33.3%) patients had the lymph node and 12 (23.5%) the bone marrow involvement. Following various combinations of treatment, complete remission was achieved in 40 (81.6%), and partial remission in three of the 49 treated patients with no difference in response rates between different disease stages. Relapse occurred in 12/43 (27.9%) patients among whom eight (18.6%) recurred in the presenting organ system. Five patients (9.8%) died because of a rapid disease progression after a median follow-up of 56 months; two patients with primary lung lesions, 1 patient with secondary intestinal disease, and 2 patients suffered transformation to diffuse large B-cell lymphoma. No significant difference in survival was found between localized and disseminated disease (log rank 0.05, df = 1, P = 0.81). A patient age > or = 60 yr at diagnosis and presentation with the nodal disease were found to be statistically significant negative prognostic factors (P < 0.05). Median OS was not reached after 145 months of follow-up, with the estimated OS being 88% at 2 yr, and 78% at 5 yr.

Long-term outcome following Helicobacter pylori eradication in a retrospective study of 105 patients with localized gastric marginal zone B-cell lymphoma of MALT type

BACKGROUND

Treatment aimed at eradicating Helicobacter pylori infection results in lymphoma remission in most localized gastric mucosa-associated lymphoid tissue (MALT) lymphomas. The aim of this survey is to investigate the long-term effect of this therapeutic approach in a large series of patients.

METHODS

One hundred and five patients with localized gastric MALT lymphoma were initially treated only with H. pylori eradication regimens. Lymphoma responses were graded using the Wotherspoon score.

RESULTS

Helicobacter pylori, detected by histology in 81% of cases, was eradicated in all positive patients. Histological regression of the lymphoma was achieved in 78 of 102 assessable patients [76%, 95% confidence interval (CI): 67% to 84%] with complete remission (score 0-2) in 66 and partial remission (score 3) in 12. At a median follow-up time of 6.3 years, histological remission was consistently confirmed in 33 of 74 assessable patients, while 25 had score fluctuations (from 0 to 4) and 13 presented a lymphoma relapse (score 5). Only one patient had a distant progression. Transformation to a large-cell lymphoma was seen in two cases. The 5- and 10-year overall survival is 92% (95% CI: 84% to 96%) and 83% (95% CI: 70% to 91%), respectively. Only one patient died of lymphoma after transformation to a high-grade lymphoma.

CONCLUSIONS

Helicobacter pylori eradication resulted in complete lymphoma remission in the majority of cases. Long-term clinical disease control was achieved in most patients. A watch and wait policy appears to be safe in patients with minimal residual disease or histological-only local relapse.

Systemic lymphoproliferative diseases

With advancements in diagnosis and treatment for lymphoma, it is important that physicians be up to date in the management of these lymphoproliferative disorders, their associated complications, and the complications of treatment. The importance of a thorough examination of the oro-facial complex and neck on all patients cannot be overemphasized. Oral and maxillofacial surgeons continue to make significant contributions in what has become a multidisciplinary approach to managing lymphoproliferative disease.

Results of bone marrow examination in 275 patients with histological features that suggest an indolent type of cutaneous B-cell lymphoma

Whether or not bone marrow biopsies should be performed routinely in patients with skin lesions that show histological features consistent with an indolent B-cell lymphoma [marginal zone lymphoma (MZL) or follicle centre lymphoma (FCL)] has been debated. As no studies have addressed this question for this group of lymphomas, we evaluated the results of bone marrow biopsy examination in 275 patients with histological features consistent with MZL (n = 82) or FCL (n = 193) first presenting in the skin. In the MZL group, two of 82 patients (2%) showed bone marrow involvement, which was the only extracutaneous localization in one of these patients. In the FCL group, 22 of 193 patients (11%) had bone marrow involvement and was the only extracutaneous localization in nine of them. FCL patients with skin lesions and a positive bone marrow had a significantly worse prognosis when compared with patients with only skin lesions (5-year disease-specific survival 63% vs. 95%; P = 0.001). These results indicate that bone marrow investigation is essential for staging patients with a FCL first presenting in the skin. Bone marrow examination appears to have limited value in patients with MZL presenting in the skin.