Immunopathology of non-Hodgkin lymphomas

Mycosis fungoides: developments in incidence, treatment and survival

BACKGROUND

Prior studies have demonstrated improved disease-specific survival of mycosis fungoides (MF) patients over the last 50 years.

OBJECTIVE

To analyse patterns of survival and incidence from 1973 to 2016 and determine whether apparent improvements in MF-specific survival are due to lead-time bias rather than improvements in treatment.

METHODS

We performed an analysis of 10 155 patients diagnosed with MF from 1973 to 2016 in the United States cancer registries of SEER-18. We also performed a literature review of papers including stage data for unselected populations of MF patients prior to 2000.

RESULTS

Incidence of MF increased from 3.0 per million person-years in the 1970s to 5.9 in the 2010s. For all cohorts, non-Hodgkin lymphoma (including MF) was the leading cause of death. Survival analysis demonstrated marked improvement in disease-specific and overall survival from the 1970s to 2010s. Based on systematic review of the literature, 32%-73% of patients diagnosed prior to 2000 were diagnosed with early-stage disease, as opposed to 81% of patients in the SEER 2000-2016 cohort (P < 0.035 for all cohorts).

CONCLUSIONS

Although there have been improvements in MF-related survival over the last 50 years, these may reflect improvements in our ability to diagnose early-stage disease rather than improved treatment.

Immunophenotype analysis of B-CLL lymphoma and immunocytoma

The differential diagnosis between lymphocytic lymphoma of the B-CLL type and immunocytoma (IC) can be difficult when it is based only upon morphological criteria. With the aim of improving the distinction between these subgroups, frozen sections of lymph nodes or other biopsied tissues from 14 cases of B-CLL and 16 cases of IC were investigated according to immunophenotype. A panel of 13 B cell-associated and 2 T cell-associated monoclonal antibodies was used. All but one of the B-CLL cases were FMC7-, while 14/16 IC cases were FMC7+ (p less than 0.001). The two negative IC cases were both of the lymphoplasmacytic type, claimed to be "more differentiated" than the lymphoplasmacytoid type. We suggest that the cells in these cases are mature enough to have lost their FMC7 positivity, similar to plasma cells. There was also a statistically significant (p less than 0.01) difference, although not as pronounced, for the anti-CD38 antibody (Leu-17, B-CLL: 3/14, IC: 10/16 positive). No significant difference in expression of determinants was found for any of the other antibodies.

Correlation between histology and immunophenotype in a series of 322 cases of non-Hodgkin's lymphoma

The non-Hodgkin's lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms displaying a wide variation in cell morphology, histological patterns, immunological phenotype and prognosis. In this paper we compare the results of phenotypic investigation of 322 tissue biopsies with the histology based on the Kiel classification. Immunological analysis revealed that 81 per cent of these tumours were of B cell origin, 12 per cent of T cell origin and the remaining 7 per cent could not be characterized as representing either cell lineage. This last group included a number of cases which had received a histological diagnosis of true histiocytic lymphoma. The original morphological diagnosis, based on routine haematoxylin and eosion sections correlated with the immunologically determined phenotype in 86 and 93 per cent of the T- and B-cell cases respectively. The B cell tumours were phenotypically heterogenous with respect to immunoglobulin (Ig) heavy chain and B lymphocyte subset marker expression. IgG was most often found associated with NHL of cb/cc histology and a small subgroup of lymphocytic NHL. IgA expression was uncommon and occurred in combination with IgD and G in three cases and alone in two cases of NHL. The most common immunoglobulin isotype expressed was IgM this isotype occurred with IgD most often in lymphocytic and centrocytic NHL and less often in tumours of cb/cc histology. Whilst greater than 90 per cent of the lymphocytic NHLs expressed the CD5 antigen, between 20 and 75 per cent of B-cell tumours of other histologies also expressed this epitope. The CD10 antigen and the epitope recognized by the monoclonal reagent FMC7 were widely distributed on tumour cells from all histologies. TdT expression commonly regarded as a marker for immature cells was found in one case of follicle centre cell lymphoma. All cases of T cell NHL displayed marked heterogeneity for both pan T and T subset antigens which is significant in terms of the routine diagnosis of T NHL and with regard to the rational classification of node based T NHL. Unlike resting peripheral blood T cells, MHC class II, OKT 10 and CD25 epitopes were expressed reflecting activation of tumour populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Phenotypic heterogeneity displayed by T-non Hodgkin's lymphoma (T-NHL) cells dispersed from diagnostic lymph node biopsies

In this communication we present the results of the study of the surface antigen expression of cells dispersed from 19 fresh lymph node biopsies. All cases subsequently received a histological diagnosis of T-cell lymphoma (T-NHL). The monoclonal antibody (Mab) panel employed for surface staining of viable cells contained reagents reactive with the sheep red blood cell receptor (OKT11) and T3-receptor associated determinants (UCHT1, OKT3) and a range of surface antigens found on subsets of T-cells. These antibodies are characterized according to their CD group as allocated by the First and Second Monoclonal Antibody Workshops. Cells were also stained with Mabs reactive with MHC class II subregion products. All 19 cases displayed marked heterogeneity for both pan-T-cell and T-subset antigens. An observation which is significant in terms of the routine diagnosis of T-NHL and with regard to the rational classification of node-based tumours of T-cell origin. Unlike resting peripheral blood T-cells, MHC class II subregion products were expressed on most of the cases examined though Tu22, directed towards a monomorphic determinant of HLA-DQ, stained fewer cells than other antibodies. Aberrant expression of MHC class II on lymphoma cells may reflect the activation of the tumour population.

Macrophage infiltration in non-Hodgkin's lymphomas: a quantitative in situ study

The frequency and distribution pattern of macrophages within 93 non-Hodgkin's lymphomas (NHL) were evaluated in situ by immunomorphometry using stereological methods. For the identification of macrophages (M phi), several antibodies (Mono 1, Mono 2, OKM 1) reactive with surface antigens on cells of the monocyte-macrophage series and cytochemical staining for acid phosphatase were applied. The average number of macrophages within lymph node tissue of NHL was 6,299 +/- 760 cells/microliter (similar to reactive lymphatic tissue: 6,559 +/- 1,027). The highest number of infiltrating macrophages was detected in immunoblastic NHL (17,306 +/- 2,773), differing significantly from other histological subtypes and reactive lymphatic tissue (p less than 0.005). The possible impact of tumor-infiltrating macrophages on lymphoma cell proliferation and differentiation is discussed.