Mantle cell lymphoma (MCL) is a distinct lymphoma subtype with a particularly poor clinical outcome. The clinical relevance of the morphological characteristics of these tumours remains uncertain. The European MCL Network reviewed 304 cases of MCL to determine the prognostic significance of histopathological characteristics. Cytomorphological subtypes, growth pattern and markers of proliferation (mitotic and Ki-67 indices) were analysed. In addition to the known cytological subtypes, classical (87AE5%), small cell (3AE6%), pleomorphic (5AE9%) and blastic (2AE6%), we identified new pleomorphic subgroups with mixtures of cells (classical + pleomorphic type; 1AE6%) or transitions (classical/pleomorphic type; 1AE6%), which, however, did not differ significantly in overall survival time. Exactly 80AE5% of cases displayed a diffuse growth pattern, whereas 19AE5% of cases had a nodular growth pattern, which was associated with a slightly more favourable prognosis. A high proliferation rate (mitotic or Ki-67 indices) was associated with shorter overall survival. Cut-off levels were defined that allowed three subgroups with different proliferation rates to be discriminated, which showed significantly different clinical outcomes (P < 0AE0001). Based on this large clinicopathological study of prospective clinical trials, multivariate analysis confirmed the central prognostic role of cell proliferation and its superiority to all other histomorphological and clinical criteria.

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Mantle cell lymphoma (MCL) is a malignant lymphoma associated with a relatively aggressive clinical course and a median overall survival time of 3-4 years. Treatment usually consists of combination chemotherapy, often including topoisomerase (topo) inhibitors such as doxorubicin, etoposide and mitoxantrone. Topo IIa is an enzyme that is needed whenever uncoiling of DNA is necessary during the cell cycle. The enzyme is a marker of cell proliferation. We analyzed the expression of topo IIa in relation to Ki-67 and the clinical outcome in patients with MCL. Biopsy specimens from 95 untreated patients enrolled in two multicenter trials (1975)(1976)(1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985) were investigated immunohistochemically with monoclonal antibodies against topo IIa (Ki-S4) and Ki-67 (Ki-S5). Patients with low (0-10%) topo IIa expression had a median overall survival time of 49.0 months, compared to 17.0 months for patients with high (more than 10%) topo IIa expression. The Kaplan-Meier analysis showed a significant difference in the overall survival time related to the percentage of topo IIa (Po0.001) and Ki-67 (Po0.001) positive tumor cells. Multivariate Cox regression analysis revealed the expression of topo IIa as the most important prognostic factor (Po0.001) in MCL superior to the international prognostic index (IPI), the Ki-67 index and other clinical characteristics.

This study was undertaken to analyze the differentiation profiles assessed by immunophenotyping in AIDS-related B-cell lymphoma (ARL) and their relation to the clinical course. Paraffin-embedded sections of 89 ARL cases during 1989 to 2004 were stained immunohistochemically with antibodies to CD3, CD10, CD20, CD38, CD138/Syndecan-1 (Syn-1), multiple myeloma-1/interferon regulatory factor-4 (MUM1/IRF4), B-cell lymphoma protein-2 (BCL-2), BCL-6, latent membrane protein-1 (LMP-1), and Ki-67. Expression of CD10 and CD20 were associated with better overall survival (OS; P ‫؍‬ .009 and P ‫؍‬ .04, respectively). Expression of CD20 was associated with longer disease-free survival (DFS; P ‫؍‬ .03), whereas expression of CD138/Syn-1 was associated with shorter DFS (P ‫؍‬ .03). OS and DFS were worse in patients with immunophenotypic profiles related to post-germinal center (GC) differentiation (BCL-6 and CD10 negative, MUM1/IRF4 and/or CD138/ Syn-1 positive) when compared with GC differentiation (P ‫؍‬ .01). When controlled for age-adjusted International Prognostic Index (IPI), prior AIDS-defining illness (ADI), and year of ARL diagnosis, a post-GC differentiation remained significantly associated with poor OS and DFS. Expression of CD10 was associated with a preserved immunocompetence, whereas CD20 was less frequent in patients developing ARL while on highly active antiretroviral therapy (P ‫؍‬ .04). In summary, lack of CD20 or CD10 expression and a postgerminal center signature are associated with a worse prognosis in ARL. (Blood. 2005;106:1762-1769)

Minichromosome maintenance protein 6 (MCM6) is one of six proteins of the MCM family which are involved in the initiation of DNA replication and thus represent a marker of proliferating cells. Since the level of cell proliferation is the most valuable predictor of survival in mantle cell lymphoma (MCL), we investigated lymph node biopsy specimens from 70 patients immunohistochemically with a monoclonal antibody against MCM6. The percentage of MCM6 expressing lymphoma cells ranged from 12.0 to 95.6%, with a mean of 61.0%, and was significantly higher than the percentage of Ki-67-positive cells (Po0.0001). Surprisingly, the ratio of MCM6-positive cells to Ki-67-positive cells was higher than in normal stimulated peripheral blood mononuclear cells, indicating a cell early G1-phase arrest in MCL. A high MCM6 expression level of more than 75% positive cells was associated with a significantly shorter overall survival time (16 months) compared to MCL with a low MCM6 expression level of less than 25% (no median reached, Po0.0001). Multivariate analysis revealed MCM6 to be an independent predictor of survival that is superior to the international prognostic factor and the Ki-67 index. Therefore, aside from gene expression profiling, immunohistochemical detection of MCM6 seems to be the most promising marker for predicting the outcome in MCL.

The aim of our study was to investigate the role of immunopathological processes in the pathogenesis of chronic sclerosing sialadenitis of submandibular glands (Küttner tumor). For this purpose, biopsy specimens from submandibular glands of 22 patients with the histological diagnosis of chronic sclerosing sialadenitis were analyzed. Paraffin-embedded tissues were immunostained for T-lymphocyte subsets (CD3, CD4, CD8), cytotoxic T cells (granzyme B), B cells (CD20, Ki-B3), and macrophages (Ki-M1P). Polymerase chain reaction and capillary electrophoresis were used to detect rearrangements of the T-cell receptor gamma chain and the CDRIII region of the immunoglobulin heavy chain. In all cases, abundant cytotoxic T cells were found, especially in close association with ducts and acini. T-cell receptor gamma chain rearrangements showed a monoclonal pattern in 6 cases (27.3%), an oligoclonal pattern in 8 (36.4%), and a polyclonal pattern in 8 (36.4%). The B-cell reaction was less pronounced and largely restricted to lymph follicles. Molecular analysis of immunoglobulin heavy chain revealed a polyclonal rearrangement in 17 cases (77.3%). In conclusion, there is an intimate relationship between the T-cell-dominated inflammatory infiltrate and acinar and duct cells. This, together with the frequent demonstration of monoclonal and oligoclonal populations of cytotoxic T cells and their histopathological behavior, suggests that chronic sclerosing sialadenitis may be the result of an immune process triggered by intraductal agents.

The presence of sclerosis within the lymphoma is a marker of poor overall survival that is independent of the FLIPI. The quantification of macrophage or absolute T-cell content, grading, and proliferation are of no help in predicting the outcome of FL. Future studies need to identify surrogate markers for the prognostic immune signatures identified by gene expression profiling. Most importantly, new prognostic markers need to be confirmed in patients treated within prospective trials.

The significantly elevated frequencies of cytotoxic cells in the submandibular glands of patients with irradiation-induced sialadenitis suggest that cell-mediated immune mechanisms may play a part in the pathogenesis of this disease.