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Notes: Multinucleate giant cells resembling Warthin-Finkeldey cells have been described in various lymphoid disorders. These Warthin-Finkeldey-like cells (WFLC) with as many as 50 nuclei are of three main types: reticular, lymphocyte and intermediary. In reactive lymphoid proliferations (34 cases) WFLC were mainly observed inside germinal centres and to a lesser extent in the interfollicular zones. In neoplastic lymphoid proliferations (33 cases) WFLC were most commonly found in the lymphocytic predominance type of Hodgkin's disease (16/25 cases). All non-Hodgkin's lymphomas (13 cases) in which WFLC were detected proved to be of low grade malignancy (lymphocytic: one case, lymphoplasmacytic-plasmacytoid: six cases; and centroblastic-centrocytic, six cases). They were also found in two cases of angioimmunoblastic lymphadenopathy. Immunoperoxidase and electron microscopic studies could not elucidate the exact histogenesis of these cells, but it is assumed that they are associated with B cell proliferations.

Notes: By in situ hybridization with EBER oligonucleotides and immunohistochemistry with anti-latent membrane protein 1 (LMP1) antibody, we compared the detection rate of Epstein–Barr virus (EBV) in Hodgkin's disease and anaplastic large-cell lymphomas in children. Among the 13 cases of Hodgkin's disease tested, 7 (54%) were found to be EBV associated (EBER transcripts +, LMP1 +). None of the 11 cases of ALC lymphomas was found to contain EBV genomes or gene products. This may indicate that EBV is not a pathogenic agent in anaplastic large-cell lymphomas in children in comparison to Hodgkin's disease.

Notes: The AMeX method (cold Acetone fixation with subsequent Methyl benzoate and Xylene treatment and routine paraffin embedding) has been recently revived for simultaneous preservation of morphology of cells and their antigens. We propose a modification of this method (ModAMeX), with the use of proteolytic enzyme inhibitors and low temperature paraffin wax embedding, which results in better preservation of a large number of leucocyte differentiation antigens and diagnostic morphologic detail. T-cell antigens (CD1, CD2, CD3, CD7 & CD8), B-cell antigens (CD22), macrophage associated antigens (CD11c, CD14 and others), activation antigens (CD25 and others), as well as some other antigens of diagnostic interest (CD10) were found to be preserved with a staining intensity equal to that of sections of fresh frozen tissue. Although the staining intensity of other T-cell antigens (CD4 & CD5), B-cell antigens (CD19, CD21 & CD37), activation antigens (Ki-1) and nuclear proliferation antigen (Ki-67) was slightly weaker as compared with frozen sections, this could be corrected by increasing the monoclonal antibody concentration. Staining for heavy and light chains of immunoglobulins was minor, sometimes compromised due to persistence of background staining as a result of extracellular immunoglobulins. The ModAMeX method has the advantages of simplicity, low cost and the possibility of exchange of tissue material between laboratories.

Notes: Aims:  Progressive changes have been reported in lymph nodes in HIV infection, but few accounts describe altered splenic histology at different stages of the disease. Investigation of splenic changes accompanying the progressive CD4+ T-cell depletion that occurs in HIV infection could shed light on normal immunological interactions in this organ. Therefore, we assessed the amount and distribution of lymphoid tissue in spleens from adults with documented early or advanced HIV disease.Methods and results:  Immunohistochemistry was used to study splenic tissue collected in an extensive autopsy survey of HIV+ adults in West Africa. Compared with post-mortem spleens from HIV– West African adults and control UK spleens, those from HIV-infected patients showed severe atrophy of white pulp B- and T-cell compartments. In early and advanced HIV disease, marginal zone atrophy was significant. Peri-arteriolar lymphoid sheaths contained increased numbers of CD8+/CD45RO+ T-cells in advanced HIV disease. In red pulp, early and advanced cases showed a lymphocytosis of CD8+/CD45RO– T-lymphocytes.Conclusions:  Atrophic changes were more extreme in advanced than early HIV infection. Reduced marginal zone function possibly explains the known predisposition of HIV+ patients to infection by encapsulated bacteria. Possible immunological consequences of these CD8+/CD45RO+ (peri-arteriolar lymphoid sheaths) and CD8+/CD45RO– (red pulp) responses deserve further study. Comparison of West African and UK control spleens indicated that there were no major ethnic differences in spleen structure to prevent extrapolation of our results to European adults.

Notes: The generic term aggressive B-cell lymphoma includes a variety of entities, each with particular diagnostic and therapeutic issues. To define these entities better and to help confront such issues, a workshop was organized by the European Association of Haematopathology (EAHP) and the Society of Haematology during the XI Meeting of the EAHP, held in Italy in May 2002. Participants were asked to submit cases under various categories and all cases submitted were examined and reviewed by the panel members. The panel's diagnoses formed the basis for discussion at the workshop and a limited number of cases were selected to be presented in more detail and discussed during the workshop. After the workshop the panel met again to discuss the outcome, summarized in this report, which describes the panel's proposals regarding diagnostic criteria, terminology, the definition of new entities and evaluation of biological differential and new prognostic parameters.

Notes: Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with `malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer–Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.

Notes: Recent reports demonstrated the presence of Epstein-Barr virus (EBV) in about 10% of gastric carcinoma cases, particularly in Asian populations. We carried out a retrospective assessment of the detection rate of EBV gene products in 59 cases of gastric carcinoma of various histological subtypes. In situ hybridization using non-isotopic EBER and BHLF1 oligoprobes, and immunohistochemistry using antibodies to latent membrane protein 1 (LMP-1) were applied to paraffin-embedded sections. Tumour cells in five out of 59 cases (8.5%) were found to be EBER positive by in situ hybridization, but no staining was observed with LMP-1 antibodies. Four EBER positive cases were lymphoepithelioma-like carcinomas and one case was a well differentiated adenocarcinoma, suggesting a stronger association with the former subtype. Among the four EBER positive lymphoepithelioma-like carcinomas, BHLF1 transcripts were expressed in one case in a few tumour cells, indicating the possible activation of a lytic cycle. In nine cases (including three EBER positive cases) a few scattered EBV-infected lymphocytes were seen in the normal mucosa but we were unable to detect any EBER positive normal epithelial cells. Our results show that, in a French population, the incidence of EBV-associated gastric carcinoma is similar to that in other geographic areas. The clinical implications of these findings, however, remain unclear.

Notes: The reactivity of MIB1 antibody on routinely processed paraffin sections was compared with that of Ki-67 antibody on frozen sections of 80 transitional cell carcinomas of the bladder. The percentage of labelled cells was expressed as the labelling index. MIB1 labelling indices were higher than those of Ki-67 but for each case the two values were strongly correlated (r= 0.91). Ki-67 and MIB1 indices were also correlated to tumour grade and stage (P 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:03090167:HIS563:les" location="les.gif"/〉 0.001). MIB1 indices determined after both formaldehyde and ethanol based Bouin's fluid fixatives did not show any significant difference. MIB1 antibody staining after microwave oven heating of tissue sections is a simple technique for assessing the proliferative fraction of bladder tumours on fixed material. The use of MIB1 antibody permits retrospective studies and should determine whether the proliferation index in bladder carcinoma has the same prognostic value as demonstrated in other types of neoplasms.

Notes: The expression of bcl-2 protein and Epstein–Barr virus (EBV) latent membrane protein 1 (LMP-1) was investigated in 18 cases of lymphoma occurring in the acquired immunodeficiency syndrome (AIDS). EBV small RNAs were detectable in tumour cells in all cases by in situ hybridization with EBER oligonucleotides. LMP-1 expression was detected in 61% of the cases, and 55% were positive for bcl-2. Dual expression of LMP-1 and bcl-2 was found in 8/18 (44%) cases, while five cases (28%) expressed either LMP-1 or bcl-2 and five expressed neither. Thus, there was an inconsistent relationship between the presence of EBV and the expression of bcl-2. One LMP-1 negative case was found to express bcl-2 in reactive lymphocytes but not in lymphoma cells. No clinical features were found to correlate statistically with LMP-1 or bcl-2 expression in the tumour cells. However, CD4 counts at diagnosis were significantly lower in bcl-2 positive cases (P 〈 0.05). The respective roles of EBV LMP-1 and the expression of bcl-2 in lymphogenesis in AIDS patients remains complex and is not yet fully understood.