Immunohistochemical expression of (CD15, CD20) to reclassify the Lymphocyte predominance Hodgkin's lymphoma

number: 
1413
English
department: 
Degree: 
Imprint: 
Medicine
Author: 
Dr. Ahmed Khairallah Mahdi
year: 
2006

Abstract:

The lymphocyte predominant Hodgkin lymphoma (Rye's classification) was found to be actually constituted of two different entities, with different morphological and immunohistochemical properties: • The NLPHL with characteristic L&H cells expressing the immunohistochemical pattern (CD20+ve, CD45+ve, CD15-ve, CD30-ve). • The Lymphocyte rich classical Hodgkin disease with characteristic RS cell expressing the immunohistochemical pattern (CD15+ve, CD30+ve, CD20-ve, CD45-ve). Aim of the study: To assess the expression of immunohistochemical markers namely (CD15, CD20) in malignant cells of Hodgkin's disease, to reclassify the collected lymphocyte predominance Hodgkin's lymphoma cases (Rye's classification) according to the new REAL/WHO classification depending on the immunohistochemical analysis. Patients and Method: Over the period extending from (January 2000-March 2006), Specimens from 31 cases of Lymphocyte predominance Hodgkin lymphoma (Rye's classification) as formalin fixed, paraffin embedded tissue blocks from excisional lymph node biopsies were collected for this study from the Department of Pathology of Al-Kadhemyia teaching Hospital, the Department of Pathology of Baghdad teaching Hospital, Central Health Laboratory, and several private laboratories. For each case, five representative sections were prepared. One stained with hematoxyline and eosine (H&E), and four other sections (on positively charged slides) prepared for IHC procedures using CD15, and CD20. For the evaluation of markers expression, a semiquantitative evaluation system was used to register the staining intensity and the numbers of positive cells. Results: The mean age of the patients was (19.42) years, with a range of (5-63) years. Most of the cases (84%) were below the age of 40 years, and (55%) were in the first two decades of life, with prominent overall male predominance reflected in male to female ratio of (4.2:1). The most common site of lymph node biopsy was the cervical lymph node in (61.29%) of cases. Immunohistochemically, CD20 was expressed in (12.91%) of cases, while CD15 was expressed in (77.41%) of cases. Depending on this immunohistochemical expression of markers the cases of lymphocyte predominant Hodgkin lymphoma were subdivided into NLPHL and LR-CHD, with NLPHL accounting for (13%), and LR-CHD for (87%) of total collected cases. Conclusions: 1. NLPHL exists in Iraq accounting for 13% of the lymphocyte predominant Hodgkin's lymphoma cases of Rye's classification. 2. LR-CHD exhibit, in the majority of cases, a nodular growth pattern. 3. This study has shown that HD with a nodular growth pattern and a lymphocyte-rich background encompasses 2 entities with distinct morphologic, phenotypical features. Therefore, the precise classification of such cases requires a combination of conventional histology and immunohistology with distinct panel of antibodies.