Large B-cell lymphomas with a high content of reactive T cells

Primary Cutaneous T-Cell/Histiocyte-Rich B-Cell Lymphoma: A Case Report and Literature Review

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a lymphoproliferative disorder in which the majority of cells are reactive T cells with only a minor population of neoplastic large B cells. THRLBCL is a very rare lymphoma, and most cases are nodal THRLBCL; an extranodal case of THRLBCL presenting primarily on the skin is an extremely rare occurrence with only a few cases reported in the literature. Here, we report a case of a primary cutaneous THRLBCL in a 41-year-old Saudi male who presented unusually with multiple skin lesions. He was successfully treated with electron beam radiotherapy and had a complete resolution with no recurrence as of his 24-month follow-up.

Rituximab Treatment Prevents Lymphoma Onset in Gastric Cancer Patient-Derived Xenografts

Patient-Derived Xenografts (PDXs), entailing implantation of cancer specimens in immunocompromised mice, are emerging as a valuable translational model that could help validate biologically relevant targets and assist the clinical development of novel therapeutic strategies for gastric cancer.

More than 30% of PDXs generated from gastric carcinoma samples developed human B-cell lymphomas instead of gastric cancer. These lymphomas were monoclonal, Epstein Barr Virus (EBV) positive, originated tumorigenic cell cultures and displayed a mutational burden and an expression profile distinct from gastric adenocarcinomas. The ability of grafted samples to develop lymphomas did not correlate with patient outcome, nor with the histotype, the lymphocyte infiltration level, or the EBV status of the original gastric tumor, impeding from foreseeing lymphoma onset. Interestingly, lymphoma development was significantly more frequent when primary rather than metastatic samples were grafted.

Notably, the development of such lympho-proliferative disease could be prevented by a short rituximab treatment upon mice implant, without negatively affecting gastric carcinoma engraftment.

Due to the high frequency of human lymphoma onset, our data show that a careful histologic analysis is mandatory when generating gastric cancer PDXs. Such care would avoid misleading results that could occur if testing of putative gastric cancer therapies is performed in lymphoma PDXs. We propose rituximab treatment of mice to prevent lymphoma development in PDX models, averting the loss of human-derived samples.

Predominance of CD4+ T Cells in T-Cell/Histiocyte-Rich Large B-Cell Lymphoma and Identification of a Subset of Patients With Peripheral B-Cell Lymphopenia

OBJECTIVES

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a morphologic variant of large B-cell lymphoma whose flow cytometry findings are not well characterized.

METHODS

Nineteen cases with flow cytometric immunophenotyping were identified from the case records of four institutions between 2001 and 2016.

RESULTS

In most cases, neoplastic B cells were not detected by flow cytometry. Overall, cases showed a predominance of CD4+ T cells, which in some cases was marked. Significant coexpression of CD57 was seen on CD4+ T cells where this marker was analyzed, which correlated with PD-1 expression. Two cases also showed a profound systemic B-cell lymphopenia, which was associated in one case with hypogammaglobulinemia.

CONCLUSIONS

Overall, our work challenges previous findings that cases of THRLBCL are rich in CD8+ T cells and highlights parallels between THRLBCL and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). Also, an association of THRLBCL with systemic B-cell lymphopenia has not been previously reported but may represent an underrecognized manifestation.

Cutaneous T-cell/histiocyte-rich B-cell lymphoma: a case report and review of the literature

BACKGROUND

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) primarily presenting on the skin is an extremely rare entity with only sporadic cases reported in the literature.

METHODS

We here report an extraordinary case of primary cutaneous THRLBCL with self-healing and 24 months of follow-up.

RESULTS

The lesion was a dermohypodermal/subcutaneous circumscribed ulcerated nodosity. Histological examination with immunohistochemical, molecular analysis and comparative genomic hybridization were performed. A complete staging was negative for secondary involvement.

CONCLUSION

Our case is remarkable because it is the second well-documented primary cutaneous THRLBCL in which we observed a complete self-regression of skin lesions without recurrences or dissemination of the disease. According to the literature, we highlight that the tumoral microenvironment, in our case, could play a relevant role in stopping lymphoma growth. Furthermore, this case supports the observation that THRLBCL primarily presenting on the skin shows an overall good prognosis.

Morphologic, immunphenotypic and clinical discriminators between T-cell/histiocyte-rich large B-cell lymphoma and lymphocyte-predominant Hodgkin lymphoma

BACKGROUND

Features of T-cell/histiocyte rich large B-cell lymphoma (THRLBCL) overlap with those of lymphocyte predominant Hodgkin lymphoma (LPHL). The two lymphomas may represent a spectrum of the same disease, and differentiation between the two can sometimes be difficult. We looked at histomorphologic, immunophenotypic and clinical information that may help differentiate the two entities.

METHODS

Cases of THRLBCL and LPHL were blindly reviewed and studied for histological pattern (nodular vs. diffuse), nuclear features and pattern of expression of CD20, CD30, CD57, epithelial membrane antigen (EMA) and Epstein-Barr virus (EBV). A score encompassing diffuse histology, high nuclear grade, CD20 single-cell pattern, CD30+, CD57-, EMA-, and EBV+ was estimated for the diagnosis of TCHRLBCL.

RESULTS

There were 58 cases, including 30 cases of TCHRLBL and 28 cases of LPHL. The median age was 36 years for TCHRLBCL and 21 years for LPHL (P = 0.0001). Three types of nuclei were identified (lymphocytic/histocytic, Reed-Sternberg and centroblast-like). The latter two high-grade nuclei were suggestive of TCHRLBCL. TCHRLBCL and LPHL, respectively, showed diffuse histology, 90% vs. 4% (P = 0.001), single CD20+ cells, 93% vs. 3.5% (P = 0.00004), CD30+ cells, 30% vs. 0% (P = 0.01), CD57+ cells, 41% vs. 93% (P = 0.008), EMA+ cells, 27% vs. 60% (P = 0.113), EBV+ cells, 24% vs. 0% (P = 0.117), high nuclear grade, 70% vs. 0% (P = 0.001), total score 2-7 (mean 4.68) vs. 0-2 (mean 0.72) (P = 0.001), high stage, 86% vs. 7% (P = 0.0001).

CONCLUSION

Our findings indicate that a combination of multiple parameters can help differentiate between the two diseases. Two cases originally diagnosed as LPHL were re-assigned the diagnosis of THRLBCL.

T-cell/histiocyte-rich B-cell lymphoma: Clinical presentation, management and prognostic factors: report on 61 patients and review of literature

T-cell/histiocyte-rich B-cell lymphoma (TC/HRBCL) is a rare subtype of diffuse large B-cell non-Hodgkin's lymphoma (DLBCL) with characteristic morphologic and immunophenotypic features, often misdiagnosed as Hodgkin's lymphoma and peripheral T-cell lymphoma. Few and conflicting clinical data are available in the literature addressing optimal treatment, prognosis and outcome. We retrospectively reviewed all patients diagnosed and managed at our institution between 1995 and 2004 diagnosed with T-cell-rich-B-cell lymphoma by WHO criteria. Sixty-one patients were identified. Initial pathology was incorrect in 82% of referred cases. The median age was 30 years. Seventy-one patients were males. Stage distribution was I - II in 21 patients, and III - IV in 40. Fifty-two percent of patients (32) had splenic involvement and thirty-seven patients (61%) presented with extranodal disease (22 >or= 2 sites). The International Prognostic Index (IPI) score was >or=2 in 62% of patients. All 59 newly diagnosed TC/HRBCL patients were treated with CHOP or R-CHOP combination chemotherapy +/- radiation therapy. The overall response rate was 85% and nine patients progressed on therapy. Fourteen patients relapsed with a median time of relapse of 6 months (range, 2 - 28). At a median follow-up of 22 months (range 1 - 132); 32 patients (52%) are alive with no evidence of disease. The 5-year overall survival and event free survival rates were 46% and 39% respectively. To conclude, TC/HRBCL is difficult to recognize without immunohistochemistry. It has an aggressive course and poor outcome; with most of patients presenting with advanced disease stage together with high IPI score. Treatment outcome seems to be similar to IPI matched DLBCL counterpart.

Clinical, histopathological and immunophenotypical findings in five horses with cutaneous malignant lymphoma

This study documents the clinical, histopathological, immunohistochemical and flow-cytometric findings in five horses with cutaneous non-epidermotropic malignant lymphoma (ML). The median survival time after discovery of the first subcutaneous nodules was 3.8 years (range 2-5 years: n=4). Histologically, the cutaneous ML had a pleiomorphic structure and contained a mixture of large reticulo-endothelial cells, medium-large sized lymphoid cells with a rounded nucleus and small nucleoli, many medium sized lymphoid cells with irregular nuclei, and some small lymphoid cells. Immunohistochemically (IHC) the lymphoid cells were positive for the pan-T-lymphocyte marker CD3 but negative for the B-lymphocyte markers CD21 and kappa and lambda immunoglobulin light chains. Although routine haematological examination revealed no abnormalities in the horses with cutaneous ML, changes in the peripheral blood lymphocyte population were apparent flow-cytometrically. Compared to clinically healthy horses, a decreased total percentage of cells was recorded in the lymphocyte gate. In three horses with cutaneous ML, an increase in CD4 positive cells was noticed in the monocyte gate. Flow-cytometric analysis of tumour cells collected by fine needle aspiration (FNA) suggested that the cutaneous MLs consisted primarily of CD4 and CD8 positive T-lymphocytes. The results were compared to those of a monomorphic multicentric T- and a monomorphic multicentric B-cell lymphoma. The results of immunohistochemistry and flow-cytometry were largely but not completely in accordance. In conclusion, the results of this study suggest that cutaneous non-epitheliotropic malignant lymphomas in the horse are of T-cell origin and that, after improvement of its accuracy, flow cytometric analysis of FNAs might become a useful aid to rapid tumour identification.

Primary intraocular T-cell-rich large B-cell lymphoma

We report a primary intraocular T-cell-rich large B-cell lymphoma in a 57-year-old woman who underwent 3 diagnostic vitrectomies for a presumed diagnosis of panuveitis. She developed no light perception in the left eye and underwent enucleation. Histopathologic and immunohistochemical studies on the enucleated globe disclosed a primary intraocular large B-cell lymphoma involving the choroid, vitreous, and retina. A large population of T cells was identified among the neoplastic B-cell population. B-cell immunoglobulin gene rearrangement and T-cell receptor gene rearrangement studies using the polymerase chain reaction method indicated that a monoclonal immunoglobulin kappa light chain population was present and that the T-cell population was not monoclonal. This case highlights the importance of interpreting cytologic features in vitreous aspirates in the context of the clinical situation.

Pediatric EBV-positive T-cell/histiocyte-rich large B-cell lymphoma with clonal cells in the bone marrow without overt involvement

T-cell/histiocyte-rich large B-cell lymphoma (TCHRLBCL) is a variant of large B-cell lymphoma only rarely encountered in children. Here we report the case of an 8-year-old African American boy with Epstein-Barr virus (EBV)-positive TCHRLBCL who initially presented with right submandibular, anterior cervical and supraclavicular lymphadenopathy. Cytogenetic analysis of the lymph node revealed a near-triploid karyotype with complex chromosomal aberrations. Although morphologically the bone marrow was normal, the same cytogenetically abnormal clone was detected. The patient responded to chemotherapy with CHOP (doxorubicin, cyclophosphamide, vincristine and prednisone) therapy, with disappearance of the abnormal clone from the bone marrow. The patient remains in remission 26 months after the initial diagnosis.

T-cell-rich B-cell lymphoma: a clinicopathologic study of 21 cases and comparison with 43 cases of diffuse large B-cell lymphoma

Clinicopathologic features of 21 patients with T-cell-rich B-cell lymphoma (TCRBCL) were reviewed and compared to 43 patients with diffuse large B-cell lymphoma (DLBCL) to determine if there were distinguishing clinical characteristics and differences in response or survival to CHOP therapy. For the diagnosis of TCRBCL, the current WHO criteria was used. In all of our cases, the majority of cells are non-neoplastic T cells and <10% large neoplastic B cells are present. The initial pathologic diagnosis was nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) in two cases. Patients with TCRBCL were significantly younger (median: 46 years) and had a significantly higher incidence of B symptoms (62%), hepatomegaly (33%) and marrow infiltration (33%) at presentation when compared to DLBCL (P<0.03). The CR rate after treatment was 48% for TCRBCL patients versus 79% for the DLBCL (P<0.003). Although the CR rates in between the two groups are significant, the difference in 3 years survival rates in each CR groups was insignificant (80% versus 77%). The overall survival time in the two groups was 17 months. Event-free survival time in TCRBCL was 12 months, compared with 17 months in the DLBCL (P>0.05). The frequency of patients with TCRBCL achieving CR was 52.6% whereas that of patients with DLBCL was 79% (P<0.003). The TCRBCL 3 years event-free survival 48% and overall survival 64% were 63 and 72% for DLBCL, respectively.

Spontaneous T-cell-rich B-cell lymphoma in a cynomolgus monkey (Macaca fascicularis)

A spontaneous T-cell-rich B-cell lymphoma (TCRBCL) occurred as a subcutaneous mass in the buccal region and enlarged submandibular lymph node in a 6-year-old female cynomolgus monkey (Macaca fascicularis). The constituent cells were examined by histology, immunohistochemistry and the double labeled-immunofluorescence method (dl-IF). Further, in situ hybridization (ISH) was employed to detect the gene expression of Epstein Barr virus (EBV). Histologically, the mass was comprised mainly of neoplastic large lymphoid cells and reactive small mononuclear cells. Immunohistochemically, the neoplastic large lymphoid cells were positive for CD20, CD79 alpha, MHC class II, and either IgG, IgM, or IgA. Polyclonal Ig production by the neoplastic large lymphoid cells was demonstrated by dl-IF, although IgG-positive ones predominated in number. On the other hand, most of the small mononuclear cells were positive for CD3 and were regarded as reactive T lymphocytes, while the remaining cells appeared to be histocytes or reactive B-cells. Transcripts of EBV gene were not demonstrated in these neoplastic or reactive cells by ISH. This is the first reported case of spontaneous TCRBCL in the cynomolgus monkey.

Favorable response to treatment of a child with T-cell-rich large B-cell lymphoma presenting with liver failure

The authors describe the successful management of a child with T-cell-rich large B-cell lymphoma (TCRBCL) involving the lymph nodes and liver, causing severe hepatic dysfunction. After immunohistochemical confirmation of the diagnosis, the patient was treated initially with low-dose, non-hepatotoxic chemotherapy and irradiation to the porta hepatis. Chemotherapy was gradually escalated to intensified B cell-lymphoma treatment regimens (CHOP, CYVE, COPAdM) as liver function improved. Despite prompt and notable response in the lymph nodes, the intrahepatic nodular lesions persisted radiologically. Liver function tests normalized during the course of treatment. However, radiologic studies of the liver showed abnormal regeneration with a predominant left lobe overshadowing a tiny right lobe. The patient remains in remission more than a year after completion of treatment. Judicious use of chemotherapeutic agents with or without local radiotherapy may influence the outcome and survival in children with TCRBCL involving the liver and causing abnormal hepatic function.

T-cell/histiocyte-rich large B-cell lymphoma: a heterogeneous entity with derivation from germinal center B cells

T-cell/histiocyte-rich large B-cell non-Hodgkin's lymphoma (THRLBCL) is an unusual morphologic variant of diffuse large B-cell lymphoma. We reviewed 30 cases of THRLBCL to evaluate its heterogeneity based on morphologic, immunophenotypic, and genetic features. Cases were classified according to the appearance of the large neoplastic B cells into three morphologic variants: 1) lymphocytic and histiocytic (L&H-like) (resembling the L&H cells of nodular lymphocyte predominance Hodgkin's lymphoma (14 cases); 2) centroblast (or immunoblast)-like (10 cases), and 3) Reed-Sternberg cell-like (resembling the neoplastic cells of classic Hodgkin's lymphoma) (6 cases). We used a panel of immunohistochemical stains, including those with specificity for germinal center B cells: CD20, CD79a, CD30, CD15, epithelial membrane antigen, BCL-2, BCL-6, and CD10. The /JH polymerase chain reaction assay was further performed to investigate a relationship to follicular lymphoma. The results were correlated with Epstein-Barr virus status as determined by staining for latent membrane protein and EBER-1 in situ hybridization. All cases were of B-cell immunophenotype with strong surface CD20 reactivity in the neoplastic large lymphoid cells, although CD79a was more inconsistently and weakly expressed (10 of 17). Nuclear positivity for the BCL-6 protein was detected in the tumor cells in 26 of 29 (90%) cases. However, differences in expression of other antigens were encountered in the histologic subtypes. Epithelial membrane antigen positivity, a feature often seen in nodular lymphocyte predominance Hodgkin's lymphoma, was observed in 11 of 30 (37%) cases and was most commonly seen in cases with L&H cell morphology (8 of 14; 57%). CD30 expression was observed in 9 of 30 (30%) cases but was most frequent in cases with Reed-Sternberg-like morphology (3 of 6 [50%]). CD10 expression was infrequent overall (3 of 29; 10%), with 2 of 3 positive cases identified in the centroblastic group. The overall rarity of positivity for CD10, BCL-2 (3 of 22; 13%), and -2 JH rearrangement (1 of 28; 4%) indicates a lack of connection to follicular lymphoma for all subtypes. The three cases that were negative for BCL-6 protein were LMP-1 positive and EBER-1 positive by in situ hybridization, and 2 of 3 had neoplastic cells with Reed-Sternberg-like morphology. These results demonstrate that although a large proportion of THRLBCL represent tumors of germinal center B cell derivation, they exhibit a diversity of morphologic and immunophenotypic features. A subset of THRLBCL may be related to nodular lymphocyte predominance Hodgkin's lymphoma. A small percentage show features closely resembling classic Hodgkin's lymphoma and could be considered a variant of grey zone lymphoma.

Primary cutaneous T-cell-rich B-cell lymphoma in a zosteriform distribution associated with Epstein-Barr virus infection

T-cell-rich B-cell lymphoma (TRBL) is a lately recognized B-cell lymphoma variant characterized by a minor population of neoplastic B cells existing in a background of predominant polyclonal T cells. We report an 86-year-old man with primary cutaneous TRBL associated with Epstein-Barr (EB) virus infection. Clinically, palpable scaly erythemas were distributed in a zosteriform pattern on the right abdomen. Histologically, massive cellular infiltrates were located in the upper- and mid-dermis. Higher magnification showed that the cellular infiltration was composed mainly of abnormal mononuclear, large lymphoid cells with clear cytoplasm and scattered mitoses and small lymphocytes, which represented in excess of 75% of all the infiltrating cells. Immunohistochemical staining revealed that the large cells were positive for the B cell marker, CD20, but negative for the T cell marker, CD3. On the other hand, the small cells were positive for CD3, but negative for CD20. Polymerase chain reaction (PCR) revealed EB virus DNA in the skin lesion. Primary cutaneous TRBL has only been reported in 15 cases worldwide. To our knowledge, this is the first case of primary cutaneous TRBL in a zosteriform distribution reported in the literature and the second case of primary cutaneous TRBL associated with the EB virus infection. We postulate that the EB virus may be a contributory pathogenetic event leading to monoclonal B-cell proliferation.

T-cell rich B-cell lymphoma: clinical distinctiveness and response to treatment in 45 patients

T-cell rich B-cell lymphoma (TCR-BCL) is a recently described pathologic diagnosis without a place among traditional lymphoma classification systems. In the past, TCR-BCL has been included among other diagnoses, in particular lymphocyte predominant Hodgkin's disease (LPHD). The study of TCR-BCL cohorts may elucidate clinical distinctiveness, response to therapy, and the effect of treatment regimen on outcome. Between 1992 and 1997, a hematopathologist at Memorial Sloan-Kettering Cancer Center (MSKCC) diagnosed 45 patients with TCR-BCL according to published criteria. Clinical data was collected through retrospective chart review and communication with other patient providers. Our patients presented most commonly as males in their fourth decade with advanced stage disease. Three-year overall survival (OS) and failure-free survival (FFS) were 73 and 37%, respectively. Conventional combination chemotherapy regimens were utilized for an aggressive non-Hodgkin's lymphoma (NHL) diagnosis in 26 and for a Hodgkin's disease (HD) diagnosis in 10. Disease-free survival (DFS) was significantly better for NHL (36%) vs. HD (10%) directed chemotherapy at 3 years (p = 0.003). Overall survival at 3 years was not statistically different (62 vs. 79%) due to successful salvage therapy in both groups. It is important to distinguish TCR-BCL from LPHD and classical HD. Advanced stage, extranodal disease, involvement of the mediastinum, mesentery and/or spleen are clinical clues to a TCR-BCL diagnosis. Chemotherapy directed to a NHL diagnosis rather than HD results in a significant improvement in disease-free survival. Initial Hodgkin's disease-directed (HD-directed) chemotherapy should be avoided, although salvage transplantation may result in prolonged survival.

T-cell-rich B-cell lymphoma - diagnostic and therapeutic aspects

BACKGROUND

Morphologically, T-cell-rich B-cell lymphoma (TCRB-NHL) may be indistinguishable from Hodgkin's disease (HD). Immunophenotyping may be helpful in the separation of these entities. TCRB-NHL is occasionally misdiagnosed and treated as HD. However, information is limited regarding clinical characteristics and outcome of this patient population. Furthermore, knowledge concerning any association with Epstein-Barr virus (EBV) in TCRB-NHL, as well as the immunophenotype of reactive T-cells and the expression of T-cell intracellular antigen-1 (TIA-1), granzyme B (GrB) and the CD3-zeta-chain is limited.

PATIENTS AND METHODS

We have re-evaluated 251 tumour biopsies from patients aged > or =15 years with HD diagnosed 1985-1994. Reclassification from HD to TCRB-NHL was done in 12 cases (5%). Six TCRB-NHL patients initially diagnosed and treated as B-NHL were also included. All TCRB-NHL biopsies were analysed for latent membrane protein 1 (LMP-1), CD4, CD8, CD56, CD57, TIA-1, GrB and CD3-zeta-chain.

RESULTS

Twelve cases of TCRB-NHL were initially subclassified as HD (lymphocyte predominance 5, nodular sclerosis 3, and mixed cellularity 4). Of these 12 TCRB-NHL patients, 6 were given radiotherapy alone, 5 MOPP/ABVD or similar combination chemotherapy, and one patient combined modality treatment. Male sex (p<0.05) and inguinal involvement (p<0.001) were significantly more frequent when TCRB-NHL patients receiving HD treatment (n=12) were compared with the remaining patients with confirmed (conf) HD, while no significant differences were seen with regard to stage, bone marrow infiltration, splenomegaly or cause-specific survival. Similar results were achieved when all TCRB-NHL patients (n=18) were compared to conf HD patients. Lymphoma cells in three samples stained positively for LMP-1. A decreased expression of CD3-zeta-chain was seen in 9/14 tumour biopsies.

CONCLUSION

Immunohistochemistry makes it possible to identify cases of TCRB-NHL that are morphologically difficult to distinguish from HD. The outcome of TCRB-NHL patients treated as having HD was comparable with that of the remaining HD population.

T-cell/histiocyte-rich large B-cell lymphoma: a distinct clinicopathologic entity

PURPOSE

Although it has proven difficult to delineate diagnostically reproducible and clinically relevant subgroups, the heterogeneity of diffuse large B-cell lymphomas (DLBCL) is widely acknowledged. In 1992, we reported on six cases that suggested that large B-cell lymphoma rich in stromal histiocytes and T cells may be identified as a distinct clinicopathologic entity within DLBCL.

PATIENTS AND METHODS

An integrated clinicopathologic study of 40 cases of this DLBCL subtype is presented.

RESULTS

Distinguishing a DLBCL rich in histiocytes and reactive T cells, designated T-cell/histiocyte--rich large B-cell lymphoma (THR-BCL), may be justified from a clinical point of view. The disease typically affects middle-aged male patients who usually present with advanced-stage disease that is not adequately managed with current therapeutic strategies. Whereas proliferation fraction and p53 overexpression, in addition to the clinical variables incorporated in the International Prognostic Index (IPI), significantly correlate with response to treatment and survival in a univariate analysis, only the IPI score identifies relevant prognostic THR-BCL subpopulations in a multivariate model. The morphologic and immunophenotypic profile of the neoplastic B cells in THR-BCL suggests that they may originate from a germinal center ancestor.

CONCLUSION

THR-BCL constitutes a distinct clinicopathologic entity that is characterized by an aggressive behavior. Experimental therapeutic strategies may be indicated to obtain a more favorable response to treatment in this disease.

Histiocyte-rich, T-cell-rich B-cell lymphoma: a distinct diffuse large B-cell lymphoma subtype showing characteristic morphologic and immunophenotypic features

AIMS

The clinicopathological features of histiocyte-rich, T-cell-rich B-cell lymphoma (HRTR-BCL) were first recognized in 1992. In this study, 60 cases of HRTR-BCL were analysed in order to provide a detailed morphological and immunophenotypical profile of the disorder.

METHODS AND RESULTS

HRTR-BCL is easily distinguished from other B-cell lymphomas rich in stromal T-cells by (i) a diffuse or vaguely nodular growth pattern, (ii) the presence of a minority population of CD15-, CD20+ large neoplastic B-cells, (iii) a prominent stromal component composed of both T-cells and non-epithelioid histiocytes, and (iv) the scarcity of small reactive B-cells. These criteria also enable a reliable distinction from lymphocyte-rich classical Hodgkin's lymphoma (CHL), from lymphocyte-predominant Hodgkin's lymphoma (LPHL), paragranuloma type and from peripheral T-cell lymphoma. Based on the morphology of the neoplastic cells and on their frequent bcl-6 immunoreactivity, we speculate that HRTR-BCL may be derived from a progenitor cell of germinal centre origin.

CONCLUSIONS

HRTR-BCL presents characteristic clinical features, affecting predominantly middle-aged men who present with advanced stage disease and are at high risk of treatment failure. Considering these distinctive clinicopathological features, recognizing HRTR-BCL as a lymphoma entity may be justified.

Prognostic significance of tumour-infiltrating T lymphocytes and T-cell subsets in de novo diffuse large B-cell lymphoma: a multiparameter flow cytometry study

Tumour-infiltrating T lymphocytes (TIL-T) have been implicated in playing a role in controlling tumour growth. We evaluated TIL-T in 55 cases of de novo diffuse large B-cell lymphoma (DLBCL) using three- or four-colour flow cytometric immunophenotyping (FCI). The percentage of TIL-T varied from 3% to 72% of total viable cellular events (mean 32 +/- 20%). The CD4:CD8 ratio varied from 0.17 to 13 (mean 2.3 +/- 2.2). Cases with >/= 20% T cells and those with CD4:CD8 ratios > or = 2.0 showed a significantly better overall survival (P = 0.017 and P = 0.034 respectively). These findings were independent of clinical stage at diagnosis. The T-cell percentage and CD4:CD8 ratio were moderately correlated (Spearman correlation coefficient = 0.47, P = 0.001) and multivariate analysis revealed that the association of the two factors with prognosis was mutually dependent. The T cells in 23 cases were studied for CD45RO. The mean percentage of total T cells expressing CD45RO was 86 +/- 10%. There was a trend towards better survival for those patients with a higher percentage of CD45RO+ T cells (P = 0.06). These results suggest that TIL-T, particularly CD4+ T cells, may play a role in the control of DLBCL, and measurement of T-cell percentage and T-cell subsets using FCI may be useful in predicting the clinical behaviour of DLBCL.

T-cell-rich large B-cell lymphoma in children and adolescents: a clinicopathologic report of six cases from the Children's Cancer Group Study CCG-5961

BACKGROUND

T-cell-rich large B-cell lymphoma (TCRLBCL) is a morphologic subset of diffuse large B-cell lymphoma that has been confused with Hodgkin disease and reactive lymphadenopathies. To the authors' knowledge the majority of reports of TCRLBCL are from adults, and it is not widely recognized as occurring in the pediatric population. The current study reports a cohort of six cases of TCRLBCL from the Children's Cancer Group CCG-5961 study.

METHODS

Biopsies from patients entered on CCG-5961 were submitted for central pathology review and immunophenotyping. Six cases of TCRLBCL were identified and correlated with clinical characteristics.

RESULTS

Of 86 cases centrally reviewed to date on CCG-5961, 20 (23%) were diagnosed as diffuse large B-cell lymphomas. Of these, 6 cases (7% of total cases and 30% of large B-cell cases) were TCRLBCL, based on a diffuse growth pattern with a minor population of neoplastic large B cells and an associated extensive reactive T-cell infiltrate. All patients with TCRLBCL were males ages 12-16 years. Three patients with TCRLBCL had advanced stage disease. No bone marrow or central nervous system involvement was detected in any case.

CONCLUSIONS

TCRLBCL is a morphologic subtype of diffuse large B-cell lymphoma that may be difficult to recognize due to the extensive infiltrate of reactive T cells. This entity is not well recognized in pediatric patients, but in the current study represented 7% of all cases and 30% of large B-cell lymphomas received for central review from the ongoing CCG-5961 protocol. Because TCRLBCL may be confused with Hodgkin disease and reactive lymphadenopathies, it is essential that this entity be recognized in the pediatric age group.

Primary cutaneous T-cell-rich B-cell lymphomas with flow cytometric immunophenotypic findings. Report of 3 cases and review of the literature

BACKGROUND

Primary cutaneous T-cell-rich B-cell lymphoma is a relatively rare entity that has been diagnosed most commonly using immunohistochemical and molecular techniques. Flow cytometric immunophenotyping (FCI) has not been described in this entity. We report the demonstration of B-cell monoclonality by FCI in 3 cases of primary cutaneous T-cell-rich B-cell lymphoma.

METHODS

Clinical and pathologic data were recorded for 3 cases of primary cutaneous T-cell-rich B-cell lymphoma. Immunohistochemical and FCI data were available in all cases; DNA analysis was performed in 1 case.

RESULTS

Flow cytometric immunophenotyping revealed a monoclonal B-cell population exclusively in the monocyte (large cell) region in all 3 cases. Immunohistochemistry confirmed the T-cell richness of the infiltrates within the cutaneous lymphomas; T cells accounted for 65% to greater than 90% of the cells within the infiltrates. DNA analysis by polymerase chain reaction in 1 case did not demonstrate a monoclonal rearrangement of the immunoglobulin heavy-chain gene.

CONCLUSIONS

Flow cytometric immunophenotyping in primary cutaneous T-cell-rich B-cell lymphoma may be useful in demonstrating monoclonality in these cases, especially if there is selective gating on the relatively small population of cells in the large cell region. The FCI data should be correlated with histology and immunohistochemistry.

T-cell-rich B-cell non-Hodgkin's lymphoma mimicking Hodgkin's disease

We report on a patient with recurrent T-cell-rich B-cell lymphoma (TCRBCL), initially misdiagnosed as a lymphocyte-rich Hodgkin's disease. This case exemplifies the diagnostic problems of TCRBCL and the need for immunophenotypic analysis to differentiate TCRBCL from Hodgkin's disease, nodular paragranuloma and peripheral T-cell lymphoma. A rather unusual aspect is the long disease-free interval between the excision of the node in and the late relapse in 1996. The significance of the abundant T-cell infiltration in this B-cell neoplasm will be discussed and the concepts concerning antitumor response will be reviewed. Based on epidemiological data and the clinical behaviour TCRBCL does not seem to represent a distinctive pathological entity.

Differential diagnosis between classic Hodgkin's lymphoma, T-cell-rich B-cell lymphoma, and paragranuloma by paraffin immunohistochemistry

There are significant difficulties in the differential diagnosis of lymphomas at the interface between classic Hodgkin's lymphoma and both paragranuloma and T-cell-rich B-cell lymphoma as well as at the interface between T-cell-rich B-cell lymphoma and paragranuloma. We therefore investigated 197 cases (155 classic Hodgkin's lymphomas, 32 T-cell-rich B-cell lymphomas, and 10 paragranulomas) by paraffin immunohistochemistry. Special interest was given to cases with a B-cell phenotype of tumor cells. The reactive inflammatory infiltrate in both classic Hodgkin's lymphoma and T-cell-rich B-cell lymphoma was rich in TIA-1-positive cytolytic lymphocytes, and CD57-positive cells were rarely encountered. In contrast, in paragranuloma CD57-positive cells and small B-lymphocytes predominated the background infiltrate. The tumor cells in cases of classic Hodgkin's lymphoma were positive for CD30 in 95%, for CD15 in 75%, and for CD20 in 22%. Apart from this, vimentin was expressed in >95% of the cases. All cases of T-cell-rich B-cell lymphoma were negative for vimentin, CD30, and CD15. The reactivity of the tumor cells for CD30, CD15, CD20, and vimentin together with the background reactivity for CD57 and TIA-1 seem to reliably discriminate between the entities and should therefore help to increase the interobserver reproducibility of diagnoses in the gray zone around Hodgkin's lymphoma.

Histiocyte-rich B-cell lymphoma

This is the second report of histiocyte-rich B-cell lymphoma and the first case analyzed by flow cytometry and cytogenetic study. The immunophenotype determined by flow cytometry was that of a B-cell antigen-positive, surface immunoglobulin-negative B-cell lymphoma with 79% CD11c positive histiocytes. The lymphoid cells were composed of 76% neoplastic B-cells and 24% reactive T-cells. Immunohistochemical staining showed large numbers of histiocytes positive for CD68 and lysozyme in the lymph node and the bone marrow. Neoplastic lymphoid cells were positive for CD20, CD45, CD74 and CDw75. The monoclonality of the tumor cells was established by the evidence of rearrangements of the heavy chain and kappa light chain genes and a complex clonal cytogenetic abnormalities including t(8;14)(q11;q32). The tumor cells were large, pleomorphic lymphoid cells and showed no features resembling those of the L/H cells of Hodgkin's disease as previously reported. The rapidly progressive clinical course in the present case is consistent with the clinical features shown in the original study. The histiocytic component in this tumor is presumably recruited by a lymphokine with the nature of a growth factor from the tumor cells that may also be responsible for the rapid proliferation of the tumor cells and the aggressive clinical course. This entity merits special recognition because it leads to a predictable poor prognosis and because of its potential of being misdiagnosed as true histiocytic lymphoma.

T-cell-rich B-cell lymphoma--a distinct clinicopathologic entity?

T-cell-rich B-cell lymphoma is a particular variant of large B-cell lymphomas with the morphological hallmark of a small number of large neoplastic B-cells scattered in between a dense background of reactive T-lymphocytes, while histiocytes may be admixed in variable numbers. In the typical case, the neoplastic population resembles large germinal center cells including cells similar to the L+H-variants of Reed-Sternberg cells. The immunophenotype of these tumour cells is L26 + Leu-M1-BerH2-. Apart from these unifying features, the individual cases constitute a broad spectrum of various growth patterns, so that a multiplicity of different relations to other types of malignant lymphomas are discussed in the literature. This occurs to such an extent that it may be doubted, that one deals with a distinct and separate lymphoma entity. Moreover, a close relationship exists between T-cell-rich B-cell lymphoma and lymphocyte predominant Hodgkin's disease, because there are striking similarities between the two, and, in addition, coexistence of T-cell-rich B-cell lymphoma with Hodgkin's paragranuloma has been reported. It, therefore, seems conceivable that T-cell-rich B-cell lymphoma represents a developmental stage of lymphocyte predominant Hodgkin's disease. Be that as it may: There is no doubt that, presently, the nosological position of T-cell-rich B-cell lymphoma is unsettled and still remains to be clarified.

Centroblastic and centroblastic-centrocytic lymphomas associated with prominent epithelioid granulomatous response without plasma cell differentiation: a clinicopathologic study of 12 cases

To clarify the clinicopathologic features of B-cell lymphoma associated with prominent epithelioid granulomatous responses other than immunocytomas, 12 patients were studied. There were six men and six women. The lymphoma generally affected elderly patients (median age, 58.5 years) and was mostly nodal in origin. Seven of the 12 patients had a localized lesion (stage I or II), and five had an advanced lesion (stage III or IV). Histologically, four patients showed a follicular growth pattern and eight a diffuse growth pattern. Based on the updated Kiel classification, nine patients showed centroblastic lymphomas, and three showed centroblastic-centrocytic lymphomas. The epithelioid cells were accumulated in large, poorly demarcated masses. Trabecular fibrosis compartmentalized in the lymph nodes, producing a vague nodular pattern in low-power fields. Immunohistochemical studies of the tumor cells revealed positive membrane staining with L26 in all 12 patients and with LN-1 antibody in 9 of 10 patients. Expression of the bcl-2 protein was present in all seven patients tested. Genotypic investigation exhibited germline configuration of the immunoglobulin heavy chain gene, the T-cell receptor beta-chain gene and the bcl-2 gene in all three patients investigated. By in situ hybridization, Epstein-Barr virus genomes were detected in only a few tumor cells in three of the patients tested. This study indicated that most, if not all, of the B-cell lymphomas with prominent epithelioid granulomatous responses other than immunocytoma were of follicular center cell origin.

How to differentiate between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease. Evidence for the value of MB1 and 4KB5 immunostaining

Striking morphological similarities exist between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease (Hodgkin's paragranuloma), making the distinction between them extremely difficult. Immunohistochemistry provides a means of overcoming this difficulty. Immunostaining with UCHL1, L26, MB1, and 4KB5 was performed on five T-cell-rich B-cell lymphomas and 11 Hodgkin's paragranulomas (7/11 nodular, 4/11 diffuse). L26 stained the tumour cells not only of T-cell-rich B-cell lymphomas, but also of L+H Hodgkin's disease. In contrast, MB1 as well as 4KB5 identified all of the neoplastic cells in 3/5 T-cell-rich B-cell lymphomas, but did not react with the L+H cells in 8/11 Hodgkin's paragranulomas. Some overlap of staining patterns became apparent in the remaining cases, with 2/5 T-cell-rich B-cell lymphomas showing the MB1+/4KB5+ phenotype in a tumor cell subset only. Similarly, in 3/11 Hodgkin's paragranulomas, some MB1/4KB5-positive L+H cells occurred in addition to MB1/4KB5-negative L+H cells. These cases, nevertheless, could be distinguished from one another by the numbers of MB1/4KB5-positive background lymphocytes, which were scanty or absent in T-cell-rich B-cell lymphomas and more numerous in Hodgkin's paragranulomas.

Cytologic findings in a case of T-cell rich B-cell lymphoma: potential diagnostic pitfall in FNA of lymph nodes

Fine-needle aspiration biopsy (FNAB) is a reliable diagnostic technique for most palpable masses. This technique is utilized routinely to diagnose metastatic carcinoma and melanomas in lymph nodes. However, the role of FNAB in the investigation of lymphoproliferative lesions is still controversial. Recent publications have supported the use of FNAB cytology, in conjunction with immunophenotyping, as an accurate, reliable diagnostic modality for the classification of most lymphomas (Sneige et al., Acta Cytol 1990; 34:311-322; Skoog and Tani, Diagn Oncol 1991; 1:12-18; Robins et al., Am J Clin Pathol 1994; 101:569-576; Katz, Clin Lab Med 1991; 11:469-499). We present a case of a T-cell rich, large B-cell lymphoma. Material obtained by FNAB mimicked a reactive process by both cytomorphological and immunophenotypical analysis. This case demonstrates a potential pitfall in the use of FNAB to evaluate lymphoproliferative disorders even when used in conjunction with immunophenotypic studies. The case also emphasizes the need for detailed clinical and prior pathologic information when a cytologic sample is being evaluated for a lymphoproliferative disorder. To our knowledge, the cytomorphologic findings of this particular type of lymphoma have not been previously described as seen on an FNAB.

14q+ chromosome marker in a T-cell-rich B-cell lymphoma

Cytogenetic, in situ hybridization, and molecular studies were performed in a case of T-cell-rich B-cell lymphoma. Demonstration of Ig gene rearrangements for both heavy and light chains confirmed the B-lineage restriction of the neoplastic cell population. Moreover, as expected in B-cell malignancies, all abnormal karyotypes showed a 14q+ chromosome marker involving 14q32. The origin of the extra material on the derivative 14q+, as defined by chromosome painting with a library for chromosome 11, and Southern blotting for c-myc and bcl-2 rearrangements, remains unknown.

T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease: two closely related entities?

T-cell-rich B-cell lymphoma (TCRBCL) is a recently described variant of non-Hodgkin's lymphoma. It may arise de novo or secondary to follicular lymphoma and large B-cell lymphoma. We present here seven cases of TCRBCL to emphasize a peculiar relationship to lymphocyte-predominant Hodgkin's disease. Morphologically, the neoplastic populations of all TCRBCLs, in addition to centroblast-like and immunoblast-like cells, comprised a few L+H-like elements. These neoplastic cells were all regularly scattered in a majority of reactive small T-lymphocytes as well as histiocytes. Moreover, tumour cells of TCRBCL, including the L+H-like elements of TCRBCL, expressed LCA and L26 but did not stain for Leu-M1 and BerH2, as is the case with the Reed-Sternberg cell L+H variant of lymphocyte-predominant Hodgkin's disease. Furthermore, the L26 immunoreaction in one of the cases, which otherwise presented as typical TCRBCL, disclosed a small subcapsular area resembling nodular paragranuloma because some few foci consisting of mature B lymphocytes with occasional L+H-like elements were seen. This also holds true for a second of the TCRBCLs presented that obviously coexisted with recurrent Hodgkin's paragranuloma 10 years after the primary manifestation. These findings indicate a close connection between TCRBCL and lymphocyte-rich Hodgkin's disease, and it may even be speculated as to whether TCRBCL represents merely a phenotypically different manifestation of this Hodgkin's subtype. Although the data presented here will not provide sufficient proof of this hypothesis, it seems clear that the nosology of TCRBCL in the context of current lymphoma classifications requires further elucidation.

A study of the association of Epstein-Barr virus with Burkitt's lymphoma occurring in a Chinese population

There is a strong association (approximately 95%) of endemic Burkitt's lymphoma with Epstein-Barr virus (EBV), whereas the association is weak for the sporadic form occurring in Western countries (approximately 15%). In the Middle East, North Africa and South America, 60-80% of Burkitt's lymphomas harbour EBV. These epidemiological differences suggest that either the endemicity of EBV or socio-economic conditions, or both, may influence the pathogenetic role of EBV in Burkitt's lymphoma. Since only meagre data are available on Asians, this study was performed to address this issue by studying cases from Hong Kong, where EBV seroconversion occurs in the first few years of life but the socio-economic conditions approach those of Western countries. In situ hybridization for EBV encoded RNAs (EBERs) was performed on paraffin sections of 18 cases of Burkitt's lymphoma. Labelling of the neoplastic cells was detected in five cases (27.7%). In contrast, among 54 cases of B-cell lymphomas of various subtypes studied for comparison, signals for EBER were detected in only one case each of T-cell-rich large B-cell lymphoma, anaplastic large cell lymphoma and Reed-Sternberg-like cells occurring in B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma. The strong labelling with oligo-dT probe (which hybridized with the polyadenylated ends of mRNA) in all cases suggested that the negative results were genuine and not due to poor preservation of RNA in the tissues. Thus, among B-cell neoplasms occurring in Chinese, Burkitt's lymphoma shows a statistically stronger association (P < 0.01) with EBV than with other types of B-cell lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Pyothorax-associated pleural lymphoma. A case evolving from T-cell-rich lymphoid infiltration to overt B-cell lymphoma in association with Epstein-Barr virus

BACKGROUND

Pyothorax-associated pleural lymphomas (PAPL) occur in patients with long-standing pyothorax. Epstein-Barr virus (EBV) plays an important role in its development.

METHODS

An atypical case of PAPL is reported and its clinical features are compared with those of five cases of ordinary PAPL.

RESULTS

The histology of the lymphoma changed from prominent T-cell infiltration to an overt B-cell lymphoma of diffuse, large cell-type. DNA studies of the lymphoma at the first presentation demonstrated dual rearrangement in the T-cell receptor beta (TCR beta) and immunoglobulin heavy chain J region (IgJH) genes. EBV genome analysis demonstrated monoclonal expansion of EBV-infected cells. EBV gene products were present only in large lymphocytes with B-cell phenotype. The same rearranged band of the IgJH gene, but not clonal rearrangement of the TCR beta gene, was observed in the overt B-cell lymphoma at the relapse. The same EBV-infected clone was observed throughout the course of the disease. The tumor was localized at the pyothorax wall, and cell-mediated immunity, reflected by a positive tuberculin reaction, was preserved only in the current case.

CONCLUSIONS

T-cell-rich lymphoid infiltration in the current case is a variant of EBV-associated PAPL, which is infiltrated by reactive T-cells with clonal accentuation. This is the first documented case of EBV-associated PAPL evolving from T-cell-rich lymphoid infiltration.

Monoclonal B cells and restricted oligoclonal T cells in T-cell-rich B-cell lymphoma

Immunophenotyping of lymphoma using paraffin-embedded lymphoid tissue is useful in identifying the large neoplastic B cells in T-cell-rich B-cell lymphoma (TRBL), but does not succeed in deciding clonality. We studied six cases to determine the clonal population of B and T cells of TRBL. Immunohistochemistry on frozen and paraffin-embedded material showed that the cellular population in all six cases consisted mainly of T cells; fewer than ten percent of the cells stained as B cells. However, in all cases, monoclonality of the immunoglobulin was helpful for diagnosing the B-cell neoplasia. Southern blot-yielded genetic analysis showed monoclonality of B cells in three cases, but no evidence of clonality in the T cells. Moreover, gene monoclonality has been detected in all cases examined by polymerase chain reaction, using the primers for the V and J regions of the immunoglobulin heavy chain gene. For T cells, the D and J regions of the T-cell receptor (TCR) beta chain showed the same patterns of oligoclonal bands in all cells, and the V and J regions of the TCR gamma chain showed the same bands in all. The expression of TCR V beta families was polyclonal but restricted.

Primary T-cell rich B-cell lymphoma of the common bile duct

A 34-year-old woman was hospitalized for the investigation of a one-month history of intestinal disorders, gastric heaviness and transitory icteric episodes. Extensive clinical investigations suggested the diagnosis of gall bladder carcinoma or sclerosing cholangitis. At laparotomy, the proximal part of common bile duct was markedly thickened by a white, firm, fish-flesh like tumour extending in to the cystic duct, gall bladder wall and to the liver. Histological study showed a diffuse lymphoid proliferation of the common bile duct mainly composed of small cells mixed with scattered large atypical cells. Immunohistochemistry revealed that most of the small cells expressed T-cell markers with predominant CD 4 and alpha-beta T-cell receptors and without phenotypic gap, whereas large atypical cells showed monotypic B phenotype with co-expression of mu and delta heavy chains and light lambda chain restriction. No evidence of primary nodal lymphoma was found during extensive clinical, radiological, sonographic or scanographic examinations. Sequential chemotherapy (MACOP-B) was instituted and the patient was still alive 4 years after diagnosis. Morphological and immunohistochemistry findings fulfilled criteria for a primary high grade B-cell lymphoma (centroblastic type, Kiel classification) from common bile duct concealed by numerous small reactive T-cells, so called T-cell rich B-cell lymphoma, not previously described in this location.

T-cell-rich B-cell lymphoma presenting as liver disease

We describe a series of eight cases of T-cell-rich B-cell lymphoma diagnosed on liver biopsy and collected over a period of 15 years. Of seven cases that were referred from elsewhere, in only one was the correct diagnosis of B-cell lymphoma suggested. Common errors included misdiagnosis as inflammatory disease on histology, and misinterpretation as T-cell lymphoma on immunohistochemistry. However, the cases had a distinct morphological appearance and immunohistochemical profile. They showed a lymphohistiocytic or granulomatous infiltrate, usually centred on portal tracts and containing abundant small T-cells and scanty B-cell blasts. All patients had an atypical clinical presentation which favoured non-neoplastic liver disease. In seven cases liver involvement represented Stage IV disease and in one case disease was confined to the liver consistent with a primary hepatic lymphoma. Despite combination chemotherapy, the prognosis was poor with no patients surviving beyond 15 months from diagnosis. We believe T-cell-rich B-cell lymphoma to be an under-recognized subset of non-Hodgkin's lymphoma that may mimic primary liver disease.

Primary cutaneous T-cell-rich B-cell lymphoma

A 61-year-old man presented with a skin tumour in the right axilla of 2 months' duration. An excision biopsy revealed a malignant lymphoma, of diffuse mixed small and large cell type, morphologically suggestive of T-cell lymphoma, but shown to be a T-cell-rich B-cell lymphoma by subsequent immunohistochemical staining. A review of the literature revealed 47 cases of T-cell-rich B-cell lymphoma with descriptions of primary sites, 35 nodal and 12 extranodal, of which only one was a cutaneous primary.

B cell chronic lymphocytic leukemia with florid reactive CD4+ T cell lymphocytosis in lymph nodes

This case is of an unusual florid reactive CD4+ T Cell lymphocytosis involving lymph node (LN) and overshadowing residual B chronic lymphocytic leukemia (CLL). A 65 year old female with a 9 year history of untreated B-CLL presented with weight loss, splenomegaly and lymphadenopathy. B-CLL was confirmed on the basis of peripheral blood lymphocytosis, bone marrow trephine findings and flow cytometry analysis. However, the LN biopsy showed appearances of a diffuse small lymphocytic population mimicking a leukemic T-cell infiltrate. Immunophenotyping and molecular analysis demonstrated the major cell population to be reactive CD4 positive T lymphocytes.

Epstein-Barr virus in Reed-Sternberg-like cells in non-Hodgkin's lymphomas

In the course of our study on Hodgkin's disease (HD), ten cases of non-Hodgkin's lymphomas (NHL) containing Hodgkin and Reed-Sternberg-like (HRS) cells were encountered. Many of these cases had initially been diagnosed as HD, but on careful review of the histology, with the aid of immunophenotyping studies, they were reclassified as NHL. The presence of Epstein-Barr virus (EBV) in these HRS-like cells was investigated using a combination of EBER in situ hybridization (ISH) and immunostaining for the detection of EBV-encoded latent membrane protein (LMP). HRS-like cells in four cases (two lymphoplasmacytoid lymphomas, one Richter's transformation of lymphoplasmacytoid lymphoma, and one immunoblastic lymphoma of T-cell type) were found to be EBV-positive. In two of these cases, a second biopsy taken up to 10 years later also contained EBV in the HRS-like cells. In three of the four cases, HRS-like cells expressed the activation antigen CD30, but the expression of B- or T-cell antigens was variable. All cases of T-cell-rich B-cell lymphomas were negative for EBV. In conclusion, EBV may play a role in the development of HRS-like cells in some cases of NHL. The relationship of HRS-like cells to HRS cells of HD is discussed.

Splenic involvement by aggressive malignant lymphomas of B-cell and T-cell types. A morphologic and immunophenotypic study

To determine whether there are any consistent morphologic differences between B-cell and T-cell aggressive non-Hodgkin's lymphomas of the spleen, the authors analyzed 16 spleens involved by mixed cell (1 case) or large cell (15 cases) lymphomas. Immunologic data were derived from cell suspensions or frozen tissue in each case. Five cases had a T-cell phenotype, and 11 were B-cell. Morphologic features favoring a T-cell phenotype included epithelioid histiocytic reactions, confinement of the lymphomas to the splenic T-zones (periarteriolar lymphoid sheath and marginal zone), and clear cell or polymorphous cytologic features. Features favoring a B-cell phenotype included multiple discrete nodules in the white pulp, large coalescent tumor nodules in association with small lymphocytic lymphoma, and large non-cleaved or immunoblastic plasmacytoid cytologic characteristics. Four cases were unusual because most neoplastic large cells were distributed diffusely or formed only small aggregates in the red pulp without definite tumor masses or nodules involving the white pulp. Because of this distribution and the frequently encountered erythrophagocytosis by benign-appearing histiocytes, these cases resembled malignant histiocytosis. A T-cell phenotype was predicted for all four cases; however, only one case, a lymphoma with polymorphous cytologic characteristics, was of T-cell lineage. The other three cases were of B-cell lineage. The authors' results indicate that in most instances the B-cell or T-cell nature of aggressive splenic lymphomas is predictable from the distributional and cytologic features. As in lymph nodes, there are cases for which the morphologic characteristics of B-cell and T-cell lymphomas are indistinguishable.

Large B-cell lymphoma rich in T-cells and simulating Hodgkin's disease

Unusual clinicopathological features drew our attention to nine of 208 cases diagnosed as Hodgkin's disease. Lymph node biopsy specimens in these cases were immunostained with monoclonal antibodies against B-cell, T-cell and Reed-Sternberg cell associated antigens and epithelial membrane antigen (EMA). Reed-Sternberg-like and other atypical large cells were dispersed in a diffuse, small lymphocyte-rich background, consistent more often with the initial diagnosis of diffuse, lymphocyte predominance Hodgkin's disease. The clinical stage in these cases was unusually advanced (stages III and IV). Splenomegaly was a common feature (six of nine cases), the male to female ratio was 7:2 and the median age was 55 years (range 25-77). Response to recognized regimes for Hodgkin's disease treatment was poor in most cases, and three patients died early of their disease. Large cells were B-lymphocytes expressing EMA--an immunophenotype similar to nodular, lymphocyte predominance Hodgkin's disease. Reed-Sternberg cell and T-cell associated antigens were absent on large cells. Mature T-cells, with nuclear irregularities in some instances, predominated in the background. A more appropriate diagnostic category is, therefore, T-cell-rich B-cell lymphoma. The cases represent a 4-5% erroneous diagnosis of Hodgkin's disease and further suggest that there is a need for revision of criteria for the diagnosis of the diffuse, lymphocyte predominance variant.

Utility of molecular genetic analysis for the diagnosis of neoplasia in morphologically and immunophenotypically equivocal hematolymphoid lesions

The authors reviewed retrospectively the results of molecular genetic analysis of 175 hematolymphoid lesions to assess the diagnostic utility of genotyping (analysis for immunoglobulin or beta-chain T-cell receptor gene rearrangements). All cases had been genotyped, and most were also immunophenotyped. Cases were assigned to control (90 cases) or problem groups (85 cases), depending on the absence or presence respectively of diagnostic uncertainty remaining after conventional (morphologic and immunophenotypic) analysis. All control cases had unequivocal morphologic features of non-Hodgkin's lymphoma (NHL) and had appropriate lineage-specific gene rearrangements, but immunostaining was almost as sensitive in demonstrating phenotypes that were diagnostically abnormal as well as lineage-specifying. However, genotyping was clearly diagnostically useful in the problem cases, which included a heterogeneous mixture of nodal and extranodal biopsy specimens of malignant (mostly NHL) and benign lesions. Genotyping demonstrated the appropriate absence or presence of gene rearrangements in 58 of 81 problem cases (72%) ultimately diagnosed as benign or malignant respectively, excluding four cases of Hodgkin's disease; in 25 cases (31%) this was judged to be essential to diagnosis. In the remaining problem cases genotyping did not contribute positively to diagnosis, but in no case was genotyping misleading when cautiously interpreted with primary reliance on conventional analysis and with knowledge of known causes of potentially misleading results, both positive and negative. It is concluded that although genotyping is highly sensitive and specific for hematolymphoid neoplasia, it provides little or no benefit in cases that are unequivocally malignant by conventional analysis, in cases of suspected Hodgkin's disease (HD), or for the sole purpose of lineage assignment. However, in cases whose diagnosis is uncertain after conventional analysis, the high yield of useful information from genotyping with careful interpretation warrants its application.

Non-Hodgkin's lymphoma arising in patients treated for Hodgkin's disease in the BNLI: a 20-year experience. British National Lymphoma Investigation

Twenty-two of 3033 patients with Hodgkin's disease (HD) randomised into the clinical trials of the BNLI have developed non-Hodgkin's lymphomas (NHLs) at periods up to 16 years after presentation (1 simultaneous and 1 composite), giving an incidence of 0.7%. The frequency of NHL varied from 3.8% in lymphocyte-predominant HD to 0.3% in nodular sclerosing HD. In this series, 16 patients developed high-grade NHL (12 B cell; 4 peripheral T cell) and 6 developed low-grade NHL (all B cell). The histological subtype of NHL did not appear to be related to initial histological subtype of HD or the treatment received. In histological subtypes other than lymphocyte predominant, there was commonly evidence of immunosuppression in the form of low presentation lymphocyte counts, advanced stage and systemic (B) symptoms. The results suggest that these patients have a propensity for lymphoproliferative disorders, possibly associated with some immune deficiency and the subsequent development of NHL is not treatment related. The findings also emphasise how important it is to biopsy recurrent disease.