Malignant lymphomas of follicular center cell origin in man. VI. Large cleaved cell lymphoma

Follicular lymphomas

Follicular lymphomas constitute approximately 30% of all non-Hodgkin lymphomas. These lymphomas are characterized by at least partially follicular growth pattern, but diffuse areas may be present. The proportions of follicular or diffuse areas vary also from case to case, which seems to be associated with prognosis. Follicular lymphomas should not be divided into distinct subtypes, but rather shows a continuous gradation in the number of large cells. On the bases of this grading, three groups have been defined: grades 1-3. There is a consensus that grade 3 follicular lymphomas, namely grade 3b, should be discriminated from lower-grade cases. The cells of follicular lymphomas express surface immunoglobulin, more frequently IgM+/-IgD>IgG>IgA, B-cell-associated antigens, CD10+/-; they are CD5-, CD23-/+, CD43-, and CD11c-. Follicular lymphomas express bcl-2 proteins, which is useful in distinguishing reactive from neoplastic follicles. t(14;18) is present in 70-95% of follicular lymphomas, involving rearrangement of bcl-2 gene. Clinical behavior of follicular lymphomas is heterogeneous and differs according to the histologic grade and extension of disease. Moreover, the evaluation of these malignancies is conditioned by therapeutic decision, which is also determined by main prognostic factors. The International Prognostic Index for aggressive lymphomas is not optimal for follicular lymphomas. Conversely, the Italian Lymphoma Intergroup Index and, more recently, the Follicular Lymphoma International Prognostic Index (FLIPI), designed in pre-rituximab era, seem to correlate well with outcome. Several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with follicular lymphoma. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histologic grade, tumor burden, and risk-predicting factors.

Among diffuse large B-cell lymphomas, T-cell-rich/histiocyte-rich BCL and CD30+ anaplastic B-cell subtypes exhibit distinct clinical features

BACKGROUND

The EORTC clinical trial 20901, activated in 1990, was designed to treat non-Hodgkin's lymphomas (NHL) of intermediate/high-grade malignancy according to the Working Formulation. Established in 1994, the R.E.A.L. Classification on NHL has now replaced all former classifications.

PATIENTS AND METHODS

We reanalysed all cases (n = 273) documented by material available for review according to the R.E.A.L. Classification. In addition, we subdivided cases recognised as diffuse large B-cell lymphoma (DLBCL) into three morphologically distinct categories, namely, large cleaved DLBCL (LC-DLBCL), T-cell-rich/histiocyte-rich B-cell lymphoma (T-cell-rich/histiocyte-rich BCL) and CD30+ DLBCL with anaplastic cell features (CD30+ DLBCL). Finally, T/NULL anaplastic large-cell lymphoma (ALCL) cases were subdivided into ALK+ and ALK- lymphomas. Review was performed independently by two pathologists from two different centres.

RESULTS

DLBCL (61%), T/NULL ALCL (15%) and mantle-cell lymphoma (MCL, 50%) were the main NHL categories represented in the study. Fifty-seven of one hundred sixty DLBCL cases were further subclassified as LC-DLBCL (33 cases), T-cell-rich/histiocyte-rich BCL (13 cases) or CD30+ DLBCL (11 cases). The remaining cases were indicated as unspecified DLBCL. A clinico-pathological correlation confirmed the findings of previous studies suggesting that MCL, DLBCL and ALCL represent distinct entities with MCL being characterised by a short survival, in contrast with the longer survival and less frequent progression typical of ALK+ compared to ALK- ALCL. Within DLBCL, T-cell-rich/histiocyte-rich BCL showed distinctive features at presentation whereas CD30+ DLBCL showed a trend towards a more favourable prognosis, that might be comparable to that of ALK+ ALCL.

CONCLUSIONS

Our data further support the usefulness of the R.E.A.L. Classification and illustrate the feasibility of DLBCL subtyping. Moreover, our results demonstrate the distinct clinical characteristics of T-cell-rich/histiocyte-rich BCL and CD30+ DLBCL with anaplastic cell features suggesting that they may represent clinico-pathologic entities.

Follicular large cell lymphoma: long-term follow-up of 62 patients treated between 1973-1981

PURPOSE

Investigators disagree on whether follicular large cell lymphoma (FLCL) behaves like other follicular lymphomas, with no plateau in the survival curve, or as a more aggressive but potentially curable lymphoma. We reported in 1984 results for 62 FLCL patients treated at our institution; the current report updates those results.

PATIENTS AND METHODS

Sixty-two patients referred from 1973-1981, including fifteen (24%) patients with Ann Arbor stage I-II and forty-seven (76%) with stage III-IV FLCL. Seven patients received radiation (XRT) alone, forty patients XRT and chemotherapy, and fifteen patients received chemotherapy alone.

RESULTS

The median follow-up was 14.7 years. The median survival was 5.1 years, with 21% alive at 15 years. The failure-free survival (FFS) at 10 years was 31%. Univariate analysis revealed that age, Ann Arbor stage, and the International Index correlated with survival. Performance status, number of platelets, and LDH correlated with failure-free survival.

CONCLUSIONS

FLCL responds to doxorubicin-based regimens similarly to diffuse large cell lymphoma. Patients with FLCL have the potential for prolonged failure-free survival. Variables that predict the survival in aggressive lymphomas apply as well in this type of lymphoma.

Results of treatment with high intensity, brief duration chemotherapy in poor prognosis non-Hodgkin's lymphoma

A novel chemotherapeutic approach was designed for the treatment of intermediate and high-grade histology non-Hodgkin's lymphoma using augmented (but subtransplantation) doses of chemotherapy administered at frequent intervals in the inpatient setting. For the initial evaluation of this regimen, poor prognosis patients were treated with a projected long-term survival rate of less than 25% in response to standard therapy. Between March 1982 and May 1988, 56 previously untreated patients were entered into this study; all patients had either high-grade histology (20 patients) or predominantly large cell lymphoma (36 patients). Median age was 41.5 years (range, 18 to 69 years). Poor prognosis features included: Stage IV, 71%; poor performance status (Eastern Cooperative Oncology Group scale, 2 to 4), 55%; multiple extranodal sites of disease, 52%; elevated lactic dehydrogenase (greater than 300 IU/l), 43%; and bulky (greater than 10 cm) tumor masses, 30%. Thirty-three of 56 patients (59%) were in Shipp's Category 3. During the 6-year study, the chemotherapy regimen was modified in an attempt to improve efficacy and reduce toxicity. However, most patients received a 2-month course of therapy as follows: cyclophosphamide 1500 mg/m2 intravenously (IV) on days 1, 2, and 29; etoposide 400 mg/m2 IV on days 1, 2, and 3 and 100 mg/m2 on days 29, 30, 31; doxorubicin 45 mg/m2 IV on days 29, 30; vincristine 1.4 mg/m2 IV on days 8, 22, 36, and 50; bleomycin 10 units/m2 IV on days 8, 22, 36, and 50; methotrexate 200 mg/m2 IV on days 15 and 43 followed 24 hours later by leucovorin 15 mg/m2 IV every 6 hours for six doses; and prednisone 60 mg/m2 orally on days 1 to 7 and 29 to 35. The complete response (CR) rate was 77% (95% confidence interval, 64% to 86%). There were ten relapses, only one of which occurred after 18 months of follow-up. Overall event-free survival (EFS) was 52% (95% confidence interval, 36% to 68%), with a median follow-up of 36 months. Eleven of 13 patients with small noncleaved lymphoma had CR; actuarial EFS in this subgroup was 61%. Myelosuppression occurred in all patients, with severe leukopenia (less than 1000/microliters) lasting a median of 12 days (range, 3 to 29 days); toxic deaths occurred in five patients (9%; 95% confidence interval, 4% to 19%). This intensive approach improved the response and survival of very poor risk non-Hodgkin's lymphoma patients.

T cells in follicular centroblastic/centrocytic (cleaved follicular centre cell) lymphomas at diagnosis, relapse and transformation

Although T cells are often a prominent component of follicular (+/- diffuse) centroblastic/centrocytic (cleaved follicular centre cell--FCC) lymphomas (CB/cc/F +/- D), their evolution during the course of the disease and prognostic significance are uncertain. A total of 127 histopathologic and immunophenotypic studies from 77 patients with at least one histologic diagnosis of CB/cc/F +/- D were therefore retrospectively reviewed to address these questions. The proportion of T cells in each biopsy was analysed with reference to both histologic (diagnosis--Kiel and Lukes/Collins classification, presence of transformation, growth pattern, presence of residual mantle zones, biopsy sites) and clinical (biopsy date and number, treatment status) parameters. The actuarial survival for those patients whose first or second biopsy showed CB/cc/F +/- D and had immunophenotypic studies was also compared based on the proportions of T cells present. Among the biopsies which were obtained from 0 to 153 months following diagnosis, the mean proportion of T cells was 25 +/- 18 per cent. The only histopathologic group that showed a significantly different proportion of T cells were lymphomas of large cleaved FCC type (38 +/- 20 per cent). Although the number of T cells present varied greatly between different patients and among different biopsies in the same patients, neither biopsy number nor treatment status affected the mean proportion of T cells in CB/cc/F +/- D. With the exception of those biopsies from 1 to 11 months following diagnosis, the interval time between diagnosis and biopsy also did not affect the number of T cells present. Finally, the proportion of T cells in the lymphomas could not be shown to be of prognostic importance. Thus, the proportion of T cells in de novo CB/cc/F +/- D, at relapse or in transformation does not vary in a consistent fashion. Although extremely variable, the number of T cells present cannot be considered a feature of earlier or later disease and is not of demonstrable prognostic importance. Studies of specific subsets of T cells may provide more definite associations.