No abstract

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are proposed for diagnosis, differential diagnosis, staging, prognostic factors, treatment and response criteria. The guidelines proposed here are intended to contribute to the standardization of the diagnosis and treatment of these patients, and should facilitate the future development of clinical trials that could define more precisely predictive markers for histological progression or lack of response, and evaluate new drugs or treatments.

The aim of this study is to report 46 new cases of canine T-cell lymphomas among a series of 140 lymphomas studied by immunophenotyping (incidence 32.8%). According to the updated Kiel classification adapted to the canine species, 13 were classified as low-grade and 33 as high-grade lymphomas. Among the low-grade lymphomas, five were small clear-cell lymphomas, three were pleomorphic small-cell lymphomas, and five mycosis fungoides. Among the high-grade cases, there were 11 pleomorphic mixed-, small-, and large-cell lymphomas, 6 pleomorphic large-cell lymphomas, 11 lymphoblastic lymphomas, and 5 unclassifiable high-grade plasmacytoid lymphomas. The cytohistologic features were highly suggestive of a T-cell phenotype on the basis of cell morphology (irregular nuclei and clear cytoplasms) (30/46 cases), a T-cell zone pattern, and the presence of hyperplastic postcapillary venules (22/46 cases). All 46 cases were CD3+ CD79a-, and among 34 cases investigated for CD4 and CD8 expression, 13 were CD4+CD8-, 13 were CD8+CD4-, and 8 were CD4CD8 double positive or double negative. The pleomorphic mixed lymphomas were mainly CD4+CD8- (6/7) and the lymphoblastic lymphomas were double positive or double negative (6/8). The main clinical, hematologic, and biochemical features were generalized (28/46) or regional lymphadenopathy (16/46), hepatosplenomegaly (15/46), extranodal involvement (11/46), mediastinal mass (9/46), and leukemia (8/46), which were mainly present in cases of lymphoblastic lymphomas and hypercalcemia (16/46).

MALT lymphoma is an indolent disease that usually presents as localized extranodal tumor without accompanying adverse prognostic factor, and these patients have a good outcome. However, non-GI patients seem to progress more often than GI patients.

Mucosa-associated lymphoid tissue–derived lymphoma (MALT lymphoma) is usually a very indolent lymphoma, described as localized at diagnosis and remaining localized for a prolonged period; dissemination occurs only after a long course of evolution. In our database, out of 158 patients with MALT lymphoma, 54 patients presented with a disseminated disease at diagnosis. Of these 54 patients, 17 patients (30%) presented with multiple involved mucosal sites; 37 patients (70%) presented with 1 involved mucosal site, but in 23 of these patients (44%), dissemination of the disease was due to bone marrow involvement; 12 patients (22%) had multiple lymph node involvement; and 2 patients (4%) had nonmucosal site involvement. No significant difference in clinical characteristics (sex, age, performance status, B symptoms) and biological parameters (hemoglobin [Hb] and lactate dehydrogenase levels) was observed between localized or disseminated MALT-lymphoma patients. Only β2-microglobulin level was significantly more elevated in disseminated disease patients than in localized disease patients. Complete response after the first treatment was achieved in 74% of the patients, and there was no difference between the 2 groups. With a median follow-up of 4 years, the estimated 5- and 10-year overall survival rates were similar in the 2 groups, 86% and 80%, respectively. The median freedom-from-progression survival was 5.6 years for all patients, surprisingly without any difference between localized and disseminated MALT-lymphoma patients. In conclusion, MALT lymphoma is an indolent disease but presents as a disseminated disease in one-third of the cases at diagnosis. The dissemination does not change the outcome of the patients.

Transformation is an early event in the course of the disease and is mainly observed in patients with known adverse prognostic factors or those who do not achieve CR after initial treatment. These findings may be useful to select follicular lymphoma patients for intensive therapeutic approaches.

We retrospectively analyzed 26 patients with thyroid lymphoma (TL). Patients were mostly females, with a median age of 59 yr, presenting a rapidly growing nodular goiter with or without cervical adenopathy, without symptoms related to lymphoma for 81% and hypothyroidism in 61%. A previous history of Hashimoto thyroiditis was observed in 11 patients. Six different subtypes of lymphoma were observed: 13 of 26 (50%) had diffuse large B cell lymphoma, 6 (23%) mucosa- associated lymphoid tissue (MALT) lymphoma, 3 (12%) had follicular lymphoma, 2 (7%) had Hodgkin's disease, 1 (4%) had small lymphocytic lymphoma, and 1 (4%) had Burkitt's lymphoma. Diffuse large B cell lymphoma patients presented a compressive multinodular goiter, cervical adenopathy (66%), disseminated disease (50%), and poor performance status, with a poor prognosis (5-yr survival at 44%) despite a treatment based on a multidrug regimen. MALT lymphoma arose in patients with previous history of Hashimoto disease, was localized in all but 1, and was biologically associated with hypothyroidism and a high level of serum antithyroid antibodies. With total thyroidectomy, prognosis was good (5-yr survival at 100%). We did not find any routine clinical or biological parameters that could predict the evolution from Hashimoto's thyroiditis to MALT lymphoma. In conclusion, we confirmed the histological heterogeneity of TL corresponding to different clinical presentations and different prognoses.

The diagnosis of splenic lymphoma with villous lymphocytes (SLVL) was assessed by a panel of cytologists in a series of 100 patients. Clinical and biological characteristics were analysed in relation to prognosis. SLVL is a chronic B-cell lymphoproliferative disorder characterized by splenomegaly and the presence, in peripheral blood, of lymphocytes with "villous' projections. The cytological diagnosis can be difficult in patients without an absolute lymphocytosis which was observed in 24% of cases. B-cells expressed CD19+, CD20+, CD22+, CD24+ and DBA44+, whereas the expression of CD5, CD10 and CD25 was usually negative. SLVL is a disease of the elderly with a relatively benign clinical course. In the present series the 5-year overall survival was 78%. Deaths in 15 patients were related to disease progression or treatment (nine cases). Patients with a leucocyte count > 30 x 10(9)/1 or lymphocyte count < 4 x 10(9)/1 or initially treated with chemotherapy had significantly (P < 0.001) lower overall survival than other patients. From these findings, treatment abstention should be considered in patients with favourable prognostic factors; on the other hand, the efficacy of conventional chemotherapy remains to be evaluated in patients with unfavourable prognostic factors.