Prognostic Value of the Kiel Classification of Malignant Non-hodgkin's Lymphomas

Expert second-opinion pathology review of lymphoma in the era of the World Health Organization classification

BACKGROUND

The World Health Organization (WHO) classification of hematologic malignancies, published in 2000, was designed to improve diagnostic accuracy by incorporating the latest in scientific understanding. The impact of the WHO classification on the frequency of diagnostic discrepancy in lymphoma is unknown.

METHODS

We reviewed all second-opinion pathology of lymphoma at our National Cancer Institute-designated Comprehensive Cancer Center (NCI-CCC) from January to June 2001 and from January to June 2006. Discrepancies between submitted and second-opinion diagnoses were scored based upon an a priori grading schema.

RESULTS

Major diagnostic revision was rendered in 65 of 365 cases (17.8%) in 2001 and 58 of 354 (16.4%) in 2006 (P=NS). Including cases reviewed and revised beforehand at another NCI-CCC, rates of major diagnostic revision were 21.4% and 18.6%, respectively (P=NS). Discrepancy rates varied by diagnosis, from Hodgkin lymphoma (10%) to Burkitt's lymphoma (75%). No association was seen for age, gender, race/ethnicity, biopsy type, or nature of referring center.

CONCLUSIONS

Clinically meaningful diagnostic revision occurs frequently with expert pathology review for a diagnosis of lymphoma. Despite the WHO classification, rates of diagnostic revision at our institution in 2001 and 2006 did not differ significantly. Given the potential harm from misdiagnosis, expert hematopathology review should be considered the standard of care.

Immunoblastic Lymphoma: A Clinicopathologic Study with Emphasis on the cases Intervening during or following other Disorders

Fifty-eight patients with immunoblastic lymphoma (IBL) were the object of this study. Fifteen of them (26 %) developed IBL during or after other diseases, either immunologic or neoplastic, including angio-immunoblastic lymphadenopathy, autoimmune disorders, chronic lymphocytic leukemia, Waldenström's disease, lymphoplasmacytoid lymphoma and Hodgkin's disease (subsequent IBL). The comparison between de novo and subsequent IBL revealed a significantly higher incidence of bone marrow involvement and bulky abdominal disease in the latter group, with a lower response rate to chemotherapy. The favorable primary extranodal disease of Waldeyer's ring exclusively belonged to de novo IBL, whereas the frequency of immunoglobulin abnormalities was higher in the subsequent IBL group (67 %). The stage of disease, systemic symptoms at diagnosis and response to therapy were predictive of survival. The overall complete remission (CR) rate in the whole series was 37 % and the median overall survival 14 months. Complete remitters have a median survival in excess of 60 months; all relapses occurred within the first 12 months of CR. No CNS relapse terminated the CR, and CNS prophylaxis seems unnecessary in IBL. The analysis of subsequent IBL may provide information on the pathogenesis of non-Hodgkin's lymphomas; the still poor prognosis of IBL deserves new therapeutic attempts to improve on the standard regimens.

Lymphoproliferations in the bone marrow: identification and evolution, classification and staging

Bone marrow biopsies from 3229 patients with lymphoproliferative disorders and 1156 patients with benign or reactive lymphoproliferations were investigated and criteria for distinguishing between them are given. Bone marrow involvement was found in 89% of multiple myeloma, 64% of non-Hodgkin's lymphomas and 8% of Hodgkin's disease. According to the predominant proliferative cell type there were five major entities in multiple myeloma and non-Hodgkin's lymphomas: (1) plasmacytic; (2) lymphocytic; (3) hairy cell; (4) immunocytic; (5) centrocytic. These were further classified into distinct subtypes each of which had independent prognostic significance. The mode of spread of the lymphoproliferative disorders in the bone marrow showed one of six architectural patterns, which together with the quantity of infiltration in the biopsy (reflecting the tumour cell burden) had significant predictive value. These results demonstrate the value of bone marrow biopsies in the identification, classification and staging of lymphoproliferative disorders, as well as in monitoring the course of disease and the response to therapy.

Distinctive clinical features between lymphoblastic and immunoblastic non-Hodgkin's malignant lymphomas (Kiel's classification) in a series of 141 patients

Out of a series of 427 NHML based on the Kiel classification and without previous treatment, 186 were of high grade malignancy and among them were 83 lymphoblastic (LB) and 58 immunoblastic (IB) lymphomas which were included in this study. The LB and IB, which represent the majority of high grade NHML, were compared regarding their clinical features and courses. Eight main criteria were significantly different between these two groups: age of patient, immunological history, mediastinal and pleural involvement, primary or secondary involvement of the bone marrow, secondary leukaemia, secondary meningeal involvement, and involvement of the facial region. Some of these differences (mediastinum and meningeal involvement) are related to subtypes within LB. The differences between these two groups suggest that different treatment programs may be warranted.

Spontaneous (H)-thymidine uptake in histological subgroups of human B-cell lymphomas

Spontaneous (3H)-TdR incorporation was studied in cell suspensions from 64 patients with monoclonal B-cell neoplasias. Among various incubation periods a long-term (20 h) assay with (3H)-TdR had the greatest discriminatory power versus non-neoplastic lymph node cell suspensions. The (3H)-TdR uptake correlated positively with cell volume, nuclear volume, and cells in S + G + M phase of the cell cycle. A high degree of heterogeneity with regard to (3H)-TdR incorporation was found within several histological groups of the Kiel classification, especially in low-grade malignant lymphomas of centroblastic/centrocytic origin and in the lymphoplasmacytoid groups. In highly malignant lymphomas (3H)-TdR uptake was statistically, significantly higher than in lymphomas of low-grade malignancy. Patients with localized disease (stages I and II) and those with "B'-symptoms showed increased incorporation of radioactive thymidine as compared to patients with disseminated mined by histopathology and spontaneous uptake of (3H)-TdR.

Non-Hodgkin's lymphoma. Immunohistochemical and electron microscopical findings in relation to lightmicroscopy. A study of 74 cases

From 74 patients with non-Hodgkin's lymphoma (NHL), fresh biopsy material from involved tissue was investigated histochemically and by light and electron microscopy. The results were compared with the light microscopical conclusions based on three currently utilized classifications, namely of Rappaport, Lukes, and Lennert. The separate groups of low-grade NHL appeared to consist of homogeneous cell populations, both in immunohistological as well as in enzymehistochemical and electron microscopical sense. On the contrary, high-grade NHL constituted a heterogeneous group in which supplementary (immunohistochemical, enzymehistochemical, and electron microscopical) investigation is very useful. All NHLs reacted with anti-human lymphocyte serum, including the so-called histiocytic NHLs according to the Rappaport classification, which proves their lymphocytic origin. Consequently the prefix "histiocytic" should be altered in a morphogenetically correct way. Without exception the B-cell NHLs were characterized by the presence of monoclonal immunoglobulin on the cell membrane and/or intracytoplasmically. In a part of the immunologically non-T-/non-B-/("null cell") NHLs, a B-cell origin was indicated by the presence of ATPase and/or 5' nucleotidase and a T-cell origin by the presence of dot-like acid phosphatase.