Is Hodgkin's disease a unique entity?

Hodgkin's lymphoma: the pathologist's viewpoint

Despite its well known histological and clinical features, Hodgkin's lymphoma (HL) has recently been the object of intense research activity, leading to a better understanding of its phenotype, molecular characteristics, histogenesis, and possible mechanisms of lymphomagenesis. There is complete consensus on the B cell derivation of the tumour in most cases, and on the relevance of Epstein-Barr virus infection and defective cytokinesis in at least a proportion of patients. The REAL/WHO classification recognises a basic distinction between lymphocyte predominance HL (LP-HL) and classic HL (CHL), reflecting the differences in clinical presentation and behaviour, morphology, phenotype, and molecular features. CHL has been classified into four subtypes: lymphocyte rich, nodular sclerosing, with mixed cellularity, and lymphocyte depleted. The borders between CHL and anaplastic large cell lymphoma have become sharper, whereas those between LP-HL and T cell rich B cell lymphoma remain ill defined. Treatments adjusted to the pathobiological characteristics of the tumour in at risk patients have been proposed and are on the way to being applied.

Transformation of Hodgkin's disease to high-grade B-cell lymphoma: remission after Rituximab monotherapy

PURPOSE

We demonstrate the usefulness of immunotherapy with the CD20 antibody Rituximab in a case of transformation of Hodgkin's disease (HD) to high-grade non-Hodgkin's lymphoma (NHL).

CASE REPORT

A 45-year-old women suffering from lymphocyte predominant HD of paragranuloma type (stage IVb) since 1995 showed mediastinal relapse despite of 6 cycles of chemotherapy following the COPP/ABVD-protocol in 1998. Again complete remission could be achieved after escalated BEA-COPP II therapy in May 1998. Six months later chest radiograph and CT depicted pulmonary nodules. The non-typical resection of the lung revealed pulmonary involvement of a high-grade T-cell rich large B-cell lymphoma with 100% of the tumoral cells CD20 positive. Since the symptoms occurred shortly after the BEA-COPP-escalated protocol chemotherapy resistance had to be assumed. Because of this problems and supported by the refusal of a high-dose chemotherapy with stem-cell transplantation by the patient we decided to perform a mono-immunotherapy with the monoclonal CD20 antibody Rituximab. Today, 14 months later, the patient is still in complete remission including the absence of B symptoms.

CONCLUSIONS

Immunotherapy against CD20 positive cells in cases of sequential HD and NHL seems to be an effective therapy in chemotherapy resistant cases because of the suspected clonally relation of both diseases.