Some problems on the histopathological diagnosis of non-Hodgkin's malignant lymphoma -- a proposal of a new type

A phase II study of VEPA/FEPP chemotherapy for aggressive lymphoma in elderly patients: Japan Clinical Oncology Group Study JCOG9203

The Lymphoma Study Group (LSG) of the Japan Clinical Oncology Group conducted a phase II trial of LSG12 therapy for 45 elderly patients with aggressive lymphoma to clarify whether LSG12 reduces severe infection without lowering the complete response (CR) rate in comparison with LSG4. LSG12, which consisted of a regimen of vincristine, cyclophosphamide, prednisolone, doxorubicin, vindesine, etoposide, and procarbazine (VEPA/FEPP), excluded bleomycin and methotrexate of LSG4 therapy, reduced the dosages of doxorubicin and cyclophosphamide, and increased etoposide and procarbazine dosages instead. Inclusion criteria consisted of a patient age of 70 to 75 years, a World Health Organization performance status of 0 to 2, and acceptable organ function. The treatment was completed in 47% of the patients and terminated early for disease progression in 20% and for toxicity in 16%. The CR rate was 60% (95% confidence interval [CI], 44%-74%). The 5-year overall survival (OS) rate was 42% (95% CI, 27%-57%), and the median OS time was 4.3 years. Leukopenia of grade 3 to 4 occurred in 98% of the patients, and severe infection occurred in 9%. Eight patients with hepatitis C virus (HCV) antibody showed no severe hepatic toxicity and had a better CR or OS rate than the 37 HCV-negative patients. Although the outcomes of LSG12 met our expectations with a reduction in severe infection and equivalent CR and OS outcomes compared with LSG4 and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone), the possibility of a regimen more beneficial than LSG12 for aggressive lymphoma in the elderly patient should be explored because of frequent hematologic toxicity and poor compliance in LSG12.

Primary malignant lymphoma of the brain: mutation pattern of rearranged immunoglobulin heavy chain gene

Using reverse transcription-polymerase chain reaction (RT-PCR), six primary brain lymphomas, pathologically diagnosed as diffuse large B-cell lymphoma, were examined for rearranged VH-D-JH sequences of the immunoglobulin heavy chain gene, focusing on somatic mutations and intraclonal heterogeneity. The reliability of the isolated PCR clones was confirmed by in situ hybridization (ISH) with complementarity-determining region (CDR) 3 oligonucleotide probes. Sequence analysis of the PCR clones revealed a high frequency of somatic mutation, ranging from 8.8 to 27.3% (mean 18.2%) in the VH gene segments in all the lymphomas. A significantly lower frequency of replacement (R) mutations than expected was also seen in their frameworks (FRs) in all cases. These findings suggested that the precursor cells were germinal center (GC)-related cells in these lymphomas. However, despite extensive cloning experiments, intraclonal heterogeneity was not detected in any case except for one in which it could not be ruled out. Thus, it seemed likely that all of our brain lymphomas were derived from GC-related cells and that at least most of them were from post-GC cells.

Practical utility of the revised European-American classification of lymphoid neoplasms for Japanese non-Hodgkin's lymphomas

A clinicopathological study of 515 non-Hodgkin's lymphoma (NHL) cases was performed using the revised European-American classification of lymphoid neoplasms (REAL classification) in an HTLV1-nonendemic area of Japan. The following characteristics were revealed: 1) frequency of extranodal lymphomas was high (59%) with 79% B-cell lymphomas in this series, while the overall ratio of B:T/NK lineage was 3.7:1; 2) the most common type was the diffuse large B-cell lymphoma (46%), follicle center lymphomas occurred at an incidence lower (15%) than that in European and American populations, and marginal zone B-cell lymphomas accounted for as much as 12%; 3) peripheral T-cell lymphomas were common (19%), with the unspecified type predominant (11%), while adult T-cell lymphomas were present at a level equivalent to that among European and American patients (1%). Clear segregation of survival curves was rated according to cell lineage and B-cell lymphomas had a better prognosis than T / NK-cell lymphomas. Furthermore, new subtypes in the REAL classification, such as marginal zone B-cell and mantle cell lymphomas, exhibited distinct curves. Taken altogether, the REAL classification demonstrated advantages for assessment of Japanese NHL cases.

Primary malignant lymphoma of the brain: demonstration of frequent p16 and p15 gene deletions

The p16 (MTS-1) gene, a candidate tumor suppressor gene, was examined by means of Southern blot, PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) and nucleotide analyses in 5 cases of primary malignant lymphoma of the brain. By Southern blot analysis, the p16 gene was found to be deleted in at least 4 cases, homozygously (3 cases) or hemizygously (1 case). The p15 (MTS-2) gene, another candidate tumor suppressor gene located in the vicinity of the p16 gene, to which it shows structural and functional similarity, was also found to be deleted in 4 cases. Our frequent detection (80%) of p16 and p15 gene deletions might suggest that these deletions are closely related to carcinogenesis in primary malignant lymphoma of the brain. SSCP and nucleotide analyses revealed no mutations of the p16 gene in any of the cases.

Early stage gastric lymphoma: is operation essential?

To assess the efficacy of primary chemotherapy for treatment of early stage patients with gastric lymphoma, multiple agent chemotherapy was given to patients prior to surgery. Five patients with stages IE and IIE of primary gastric lymphoma (54-65 years of age; three men, two women) were treated with multiple agent chemotherapy prior to gastric resection. In all patients the diagnosis was established by endoscopic biopsy. Two patients had stage IE disease, and three had stage IIE. Histopathologically, there was one diffuse large cell lesion and four diffuse medium cell lesions. All patients received two cycles of VEPA every 4 weeks. On the 16th to 44th day after completion of chemotherapy, total gastrectomy, systematic dissection of regional lymph nodes with resection of the caudal pancreas, and splenectomy were performed. Swelling of the regional lymph nodes was noted in four cases. In all five cases, histologic findings revealed no residual cells of malignant lymphoma in the resected specimen. None of the patients had no evidence of recurrence at 12 to 40 months after surgery. Primary chemotherapy alone thus resulted in the disappearance of malignant cells in stage IE/IIE gastric lymphoma. Our results suggest that surgery may not be an essential procedure for treatment of early stage gastric lymphoma.

Bilateral malignant lymphoma of the breast in patients with a familial history of cancer: a report of three cases

We report three cases of bilateral malignant lymphoma of the breast in patients with a familial history of cancers. All the patients had B-cell malignant lymphoma and were treated by a radical mastectomy and polychemotherapy. Bilateral tumors were detected synchronously in one case, whereas the second tumors in the other cases occurred 4 years and 8 years after the initial treatment. Although the patients had no relevant past history, these cases were notable for the fact that all were associated with a familial history of cancers. One patient had a definite familial history of breast cancer, that is to say, her mother, sister and brother all suffered from this disease. The brother of another patient died of gastric cancer while two of her uncles each suffered from sarcoma of the lower extremities and a brain tumor, respectively. As for the remaining patient, one of her maternal uncles and an aunt also died of prostate cancer and leukemia, respectively. However, only one out of seven patients with unilateral malignant lymphoma of the breast used for comparison had a familial history of cancer. A possible relationship between bilateral primary malignant lymphoma of the breast and a familial history of cancer is suggested.

Immunoglobulin idiotype expression in reactive lymphoid tissues and B-cell lymphomas

In an investigation of the immunoglobulin idiotypic expression of non-tumour and neoplastic B lymphocytes in situ, fresh-frozen specimens of reactive tonsils, lymph nodes and B-cell malignant lymphomas (B-MLs) from Japanese patients were studied immunohistochemically with 39 different anti-idiotype antibodies. In reactive lymphoid tissues, while idiotype-bearing cells were largely distributed sparsely in follicles and perifollicular areas, some were heavily crowded in particular germinal centres (GCs), suggesting the presence of oligoclonal proliferations of B-cells in GCs. Forty-eight out of 100 B-MLs reacted with anti-idiotype antibodies. This proportion was significantly higher than those reported in Western cases (27-36%), indicating that Japanese B-MLs share public idiotypes much frequently than western cases. The idiotypes demonstrated in these lymphomas, in contrast to those not expressed in any B-ML, were found much commonly in non-tumour lymphocytes, suggesting that such public idiotypes as were common in B-MLs were frequently shared by normal B-lymphocytes.

Primary orbital malignant lymphoma: a clinicopathology study of 17 cases

We investigated the clinicopathologic characteristics of 17 patients (13 men and 4 women) with primary orbital malignant lymphoma using the Working Formulation. Most of the cases belonged to the low-grade malignancy group, and more women than men were in the histologically high-grade malignancy group. The phenotype of the tumor cells was investigated immunohistochemically. All cases showed the monoclonal feature of a B-cell lineage. All patients received chemotherapy with or without radiotherapy. Of 16 subjects, 15 achieved a complete remission; none of these patients has had a recurrence since the completion of the initial therapy (range of follow-up from 16 months to 10 years). One patient died.

An immunohistochemical analysis of T cells in primary B cell malignant lymphoma of the brain

An immunohistochemical study was performed on small lymphoid cells present in frozen tissue sections of seven cases of primary B cell malignant lymphomas of the brain by using monoclonal antibodies to T cell (Leu-1, OKT-11, Leu-3a, and Leu-2a) and B cell (BA-1 and Leu-12) surface markers. In all the seven cases, positive reaction for Leu-1 and OKT-11 was seen in the majority of the small lymphoid cells which were dispersed among the lymphoma cells or clustered around blood vessels. The large neoplastic cells were unstained by these antibodies. Staining for T cell subsets with antibodies to Leu-3a and Leu-2a showed heterogeneous staining in each case. The ratio of Leu-3a+ to Leu-2a+ cells was less than one in six cases, demonstrating a suppressor/cytotoxic phenotype predominance. Most of these small lymphoid cells were negatively stained by antibodies to BA-1 and Leu-12. From these findings, it was shown that the small lymphoid cells observed in primary B cell lymphomas of the brain were of T cell lineage, distinct from the neoplastic cells, and probably reactive in nature. The implications of these findings are discussed.

T-cell phenotype is associated with decreased survival in non-Hodgkin's lymphoma

This study was undertaken to determine which if any pretreatment factors are statistically significant determinants of the clinical outcome in patients with non-Hodgkin's lymphoma. The pretreatment factors in 20 patients with T-cell lymphoma, including two patients with adult T-cell leukemia/lymphoma (ATLL), and 28 patients with B-cell lymphoma were evaluated. In a stepwise logistic regression analysis, a T-cell phenotype in addition to high grade histology and pleural involvement demonstrated a statistically significant correlation with decreased response rate, when the analysis did not include patients with ATLL. Analysis by means of the Cox proportional hazards model disclosed that the T-cell phenotype retained a statistically significant correlation with survival after adjustments for other prognostic factors, whether the study included the patients with ATLL or not. The decreased response rate and survival of Japanese patients with non-Hodgkin's lymphoma in comparison with those reported in Western countries seem to be due to increased intrusion of T-cell lymphomas. To permit a reliable comparison of reports on new chemotherapeutic regimens from different institutions, the tumor phenotype must be determined in the population studied.

Histopathology and immunohistochemistry of peripheral T cell lymphomas: a proposal for their classification

Based on the results of histological and immunohistochemical observations of a large number of peripheral T cell lymphomas from China, England, Germany and Japan, histological and cytological morphology were correlated with immunophenotype, aetiological association with HTLV-1, and clinical behaviour to produce a working classification of the T cell lymphomas. This classification, based mainly on cytological criteria, divides the peripheral T cell lymphomas into tumours of low grade and high grade malignancy. Adult T cell lymphoma/leukaemia (ATLL) is caused by HTLV-1 and belongs chiefly to the high grade category. Some tumours are characterised by an admixture of other cells (epithelioid cells, follicular dendritic cells, etc) and structures (high endothelial venules, follicles), which may indicate the secretion of lymphokines by the tumour cells. Clear cells seem to be specific for T cell lymphomas and may occur in various types of peripheral T cell lymphoma.

Malignant lymphomas as tumours of the immune system

Malignant lymphomas have traditionally been classified on solely morphological grounds. With new immunological and cytochemical techniques, it has been possible to characterize normal cells of the T-lymphocyte, B-lymphocyte, and monocyte-macrophage system. Application of these methodologies to malignant lymphomas has established their nature as neoplasms of the immune system. Within the B-lymphocyte system it is possible to identify subpopulations responsible for Burkitt's tumour, follicular (nodular) lymphomas, lymphocytic lymphomas of intermediate differentiation and well differentiated lymphocytic lymphomas. The T-lymphocyte system includes lymphoblastic lymphomas, mycosis fungoides, and Sezary's syndrome. Large-cell lymphomas are diverse, but the majority are tumours of transformed lymphocytes, usually of the B-lymphocyte system. The precise nature of the neoplastic cells of Hodgkin's disease (i.e., Reed-Sternberg cells and their mononuclear counterparts) has not yet been established. Despite previous suggestions of a B-lymphocyte or T-lymphocyte origin, recent studies with in vitro cultivation have strongly suggested derivation from the monocyte-macrophage system.