Immunohistochemical detection of ZAP-70 in 341 cases of non-Hodgkin and Hodgkin lymphoma.

Using immunohistochemical methods, we evaluated zeta-associated protein (ZAP)-70 expression in 341 cases of non-Hodgkin and Hodgkin lymphoma. In B-cell NHL, ZAP-70 was positive in five of six (83%) precursor B-lymphoblastic lymphoma, 11 of 37 (30%) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), five of 39 (13%) mantle cell lymphoma, one of 12 (8%) Burkitt lymphoma, and one of 12 (8%) nodal marginal zone B-cell lymphoma. In 22 cases of CLL/SLL, seven of nine (78%) with unmutated IgVH genes expressed ZAP-70, compared with one of 13 (8%) with mutated IgVH genes (P=0.0015 Fisher's exact test). ZAP-70 expression was not detected in diffuse large B-cell lymphoma (n=26), extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (n=24), follicular lymphoma (n=21), plasma cell myeloma/plasmacytoma (n=10), lymphoplasmacytic lymphoma (n=10), or splenic marginal zone lymphoma (n=6). In T/NK-cell NHL, ZAP-70 was positive in all extranodal natural killer (NK) / T-cell lymphoma, nasal-type (n=6) and enteropathy-type T-cell lymphoma (n=4), four of five (80%) subcutaneous panniculitis-like T-cell lymphoma, six of eight (75%) mycosis fungoides, three of five (60%) precursor T-lymphoblastic lymphoma, 10 of 17 (59%) peripheral T-cell lymphoma, two of four (50%) blastic NK-cell lymphoma, one of three (33%) T-cell prolymphocytic leukemia, 13 of 52 (25%) anaplastic large cell lymphoma, and one of six (17%) angioimmunoblastic T-cell lymphoma. Seven of 12 (58%) cutaneous CD30-positive lymphoproliferative disorders were also ZAP-70-positive. In Hodgkin lymphoma, ZAP-70 was negative in neoplastic cells in all cases tested. ZAP-70 staining in B-cell lymphomas and reactive T cells was predominantly nuclear with variable cytoplasmic staining. By contrast, ZAP-70 staining in T/NK-cell lymphomas was heterogeneous, and a shift from predominantly nuclear to predominantly cytoplasmic staining was observed, particularly in those neoplasms with high-grade morphology. In summary, ZAP-70 is expressed by many lymphoma types, correlates with immunoglobulin heavy-chain variable region gene mutational status in CLL/SLL, and can be detected reliably using immunohistochemical methods.     

The relationship between Hodgkin's disease and non-Hodgkin's lymphoma.

The final Workshop of the meeting focused on cases of Hodgkin's disease (HD) in combination with non-Hodgkin's lymphoma (NHL), either T, B, or anaplastic large cell (ALC) type. The cases selected for this session fell into five categories: nodular lymphocyte-predominance Hodgkin's disease (NLPHD) with NHL, B cell chronic lymphocytic leukemia (CLL) with HD-like transformation, follicular lymphoma (FL) with HD or anaplastic large cell lymphoma (ALCL) (composite or discordant), HD following mycosis fungoides (MF), and HD following ALCL. Taken together, these cases left the participants with the distinct impression that there is likely to be some biological relationship between HD and a variety of T cell and B cell NHL.     

Immunohistochemical detection of BCL-3 in lymphoid neoplasms: a survey of 353 cases.

The bcl-3 gene at chromosome 19q13 encodes a member of the IkappaB family involved in regulating the NFkappaB pathway. Originally identified by its involvement in the rare t(14:19)(q32;q13), BCL-3 expression has never been analyzed in a wide variety of lymphomas. We assessed BCL-3 expression in 353 cases of non-Hodgkin lymphoma and Hodgkin lymphoma using formalin-fixed, paraffin-embedded tissue specimens, a monoclonal antibody specific for BCL-3, and immunohistochemical methods. Of 172 B-cell lymphomas, 10 (6%) were positive for BCL-3, including six of 23 (26%) diffuse large B-cell lymphoma, one of 17 (6%) small lymphocytic lymphoma, one of 26 (4%) follicular lymphoma, and two of 49 (4%) mantle cell lymphoma. All other B-cell neoplasms were negative, including marginal zone lymphoma (n=24, 11 extranodal, nine nodal, four splenic), Burkitt lymphoma (n=10), lymphoplasmacytic lymphoma (n=10), lymphoblastic lymphoma (n=8), and plasmacytoma (n=5). Of 111 T/NK-cell lymphomas, 25 (23%) were positive for BCL-3, including 13 of 40 (32%) anaplastic large-cell lymphoma, three of 10 (30%) angioimmunoblastic T-cell lymphoma, two of eight (25%) extranodal NK/T-cell lymphoma of nasal type, three of 12 (25%) mycosis fungoides, one of five (20%) enteropathy-type T-cell lymphoma, and two of 21 (10%) peripheral T-cell lymphoma unspecified. All other T-cell neoplasms were negative, including lymphoblastic lymphoma (n=6), prolymphocytic leukemia (n=6), and subcutaneous panniculitis-like T-cell lymphoma (n=3). Of 70 Hodgkin lymphomas, of all types, 29 (41%) were positive for BCL-3. The relatively high frequency of BCL-3 expression in some non-Hodgkin and Hodgkin lymphoma types raises the possibility that BCL-3 is involved in the pathogenesis of these tumors, and may be a target of new therapies.     

Expression of heat-shock protein-90 in non-Hodgkin's lymphomas.

Heat-shock protein-90 (HSP90) inhibitors are currently being used in phase I clinical trials for treating patients with a variety of neoplasms including lymphomas. Using immunohistochemical methods, we assessed for HSP90 expression in 412 cases of non-Hodgkin's lymphoma. In B-cell lymphomas, HSP90 was moderately to strongly expressed in all cases of Burkitt's lymphoma (5/5, 100%), and in subsets of follicular lymphoma (17/28, 61%), diffuse large B-cell lymphoma (27/46, 59%), nodal marginal zone B-cell lymphoma (6/16, 38%), plasma cell neoplasms (14/39, 36%), small lymphocytic lymphoma/chronic lymphocytic leukemia (3/9, 33%), mantle cell lymphoma (12/38, 32%) and lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (3/10, 30%). HSP90 was weakly expressed in six of 14 (43%) cases of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue. In T-cell lymphomas, HSP90 was moderately to strongly expressed in subsets of anaplastic large-cell lymphoma (14/24, 58%; 9/12 ALK+ and 5/12 ALK-), precursor-T-cell lymphoblastic leukemia/lymphoma (20/65, 31%), unspecified peripheral T-cell lymphoma (8/43, 23%) and angioimmunoblastic T-cell lymphoma (2/17, 12%). HSP90 was weakly expressed in seven of 58 (12%) cases of mycosis fungoides. We conclude that HSP90 is commonly expressed in a subset of many types of B- and T-cell lymphoma. These data suggest that many lymphoma types are suitable targets for modulation of HSP90 activity, and that HSP90 inhibitors are a potential investigational therapy for lymphoma patients.     

The world health organization classification of malignant lymphomas in japan: incidence of recently recognized entities. Lymphoma Study Group of Japanese Pathologists

New insights into the immunology and genetics of malignant lymphomas have allowed the recognition of new entities and the refinement of previously recognized disease categories. The relative incidence of these subtypes of malignant lymphoma is also known to differ according to geographic location. In order to clarify the current status of malignant lymphomas in Japan and the relative incidences of their subtypes, 3194 patients were classified according to the new World Health Organization (WHO) classification. Among these were 3025 cases (94.71%) of non-Hodgkin's lymphoma (2189 cases (68.53%) of B-cell lymphoma, 796 cases (24.92%) of T-cell lymphoma) and 141 cases (4.41%) of Hodgkin's lymphoma. The incidences of the major subtypes of non-Hodgkin's lymphoma were 33.34% for diffuse large B-cell lymphoma, 8.45% for marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type, 8.05% for plasma cell myeloma, 7.45% for adult T-cell leukemia/lymphoma (ATLL), 6.7% for follicular lymphoma, 6.67% for peripheral T-cell lymphoma of unspecified type, 2.79% for mantle cell lymphoma, 2.6% for nasal and nasal-type T/NK cell lymphoma, 2.35% for angioimmunoblastic T-cell lymphoma, and 2.35% for precursor B-cell lymphoblastic leukemia/lymphoma, in decreasing order. The other subtypes comprised less than 2%, mainly precursor T-cell lymphoblastic lymphoma/leukemia (1.72%), anaplastic large-cell lymphoma of T- and null-cell types (1.53%), and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (1.31%). The incidence of ATLL was influenced by its high percentage (19.20%) in the south-western Japanese island, Kyushu, an endemic area of human T-cell leukemia virus type 1 (HTLV-1), but which appeared to be lower than that in a previous study. The nodular sclerosis and mixed cellularity types of Hodgkin's disease occupied 1.78% and 1.63%, respectively. These data are distinct from those in Western countries and similar in several ways to those in the East, although the relatively high rate of ATLL was attributed to the geographical difference in the etiologic factor, HTLV-1.     

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma: a clonal T-cell lymphoproliferative disorder with indolent behavior.

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma, a provisional entity in the 2005 WHO-EORTC classification for cutaneous lymphomas, is not well characterized. Fifteen cases meeting the definition of this entity were identified. Fourteen represented solitary lesions on the head/neck (n=9), upper extremity (n=4), or trunk (n=1). One patient presented with multiple lesions on the trunk and extremities. Histologically, the infiltrate showed a nodular pattern in the dermis and subcutis without epidermotropism, and had a polymorphous composition with a predominance of small to medium-sized CD4-positive T cells. Most cases showed normal T-cell antigen expression; diminished/absent expression of CD7 was seen in three cases and CD2 expression was absent in one case. All cases showed a notable reactive infiltrate including frequent B cells, plasma cells, and histiocytes. Clonal TCR gene rearrangements were detected in each case. No clonal Ig gene rearrangements were detected. Out of the 11 patients with follow-up, none showed systemic disease. The majority resolved without relapse, one without treatment, four with excision, and four with radiation therapy. One patient developed local recurrence. The patient with multiple lesions had disease progression despite chemotherapy and stem cell transplant. These cases highlight the polymorphous histology and prominent reactive B-cell component of this entity. Diagnosis requires molecular genetic analysis, as prominent cytologic atypia and immunophenotypic aberrancy are rare. The differential diagnosis includes reactive lymphoid hyperplasia, mycosis fungoides and cutaneous B-cell lymphomas. In patients with isolated cutaneous lesions, the indolent behavior of this rare T-cell neoplasm should be recognized to avoid unnecessary treatment.     

Classical Hodgkin's lymphoma: biology and grey zones

Advances in the biology of Hodgkin's lymphoma have lead to the distinction between two entities, "classical" Hodgkin's lymphoma and nodular lymphocyte predominance Hodgkin's lymphoma, previously called nodular paragranuloma, which share distinct clinical aspects. The definition of diagnostic criteria has also been helpful to separate Hodgkin's lymphoma from other lymphomas which can mimick Hodgkin's disease such as anaplastic large cell lymphomas, T-cell/histiocyte rich diffuse large B-cell lymphoma, and some peripheral T-cell lymphomas, mainly angioimmunoblastic-type. Reed-Sternberg cell, the neoplastic cell of "classical" Hodgkin's lymphoma, still retains some secrets. Despite some controversies, there is more and more evidence for a lymphoid B cell origin. The involvement of Epstein-Barr virus, cytokines and/or oncogenes expression in the pathogeny can be suggested, although the precise mechanisms leading to transformation and/or accounting for tumour progression are still elusive. Recently, the roles of the pathway implicating the activation of NFkappaB as well as the autocrine secretion of interleukin-13 have been demonstrated.     

Characterization of Non-Hodgkin''s Lymphomas Using Multiple Cell Markers: Immunologic, Morphologic, and Cytochemical Studies of 72 Cases

Tissues from 72 cases (87 specimens) of various non-Hodgkin's lymphomas were analyzed for cell markers using multiple techniques. Cell suspensions were evaluated for E, EAC, and IgGEA rosette forming cells; Fc receptor cells; and surface immunoglobulin bearing cells. Cryostat section studies topographically defined EAC binding cells. Cytochemical determinations and immunoperoxidase methods for detection of intracellular immunoglobulin and lysozyme complemented other techniques in evaluating infiltrates containing large neoplastic cells. B-cell malignancies comprised 58 cases (80%) of this series and included well and moderately well differentiated lymphocytic lymphomas (10/10); nodular (23/23) and diffuse (10/18) poorly differentiated lymphocytic lymphomas; and lymphomas of mixed lymphocytic-“histiocytic” (3/3), “undifferentiated” (3/3), and “histiocytic” (9/13) types. Nodular lymphomas were characterized as B-cell neoplasms but also revealed a prominent population of T lymphocytes (39 ± 12%). Alkaline phosphatase activity, a cytochemical marker for lymphoid cells of follicular cuffs, was most consistently observed in B-cell lymphomas of moderately well differentiated lymphocytic type (4/6 cases). In some diffuse lymphomas, cryostat section studies (EAC rosettes) suggested a pre-existing nodular proliferation. One unusual B-cell lymphoma of large cell type exhibited IgGEA rosette formation and a strong receptor for the Fc portion of IgG. Ten lymphomas (14%) were of T-cell type and were represented by cases of diffuse poorly differentiated lymphocytic lymphoma (5/18, including 3 lymphoblastic lymphomas), Sézary syndrome (1), mycosis fungoides (1), and a cytologically distinctive large cell (“histiocytic”) lymphoma (3/13). Acid phosphatase activity was a consistent marker for the T-cell malignancies, some of which also revealed α-naphthyl butyrate esterase activity. No true histiocytic lymphomas were detected. Three cases of diffuse poorly differentiated lymphocytic lymphoma and one “histiocytic” lymphoma were null.     

Full clinical recovery after topical acyclovir treatment of Epstein-Barr virus associated cutaneous B-cell lymphoma in patient with mycosis fungoides

Primary cutaneous T- and B-cell lymphomas are a heterogeneous group of diseases with varied clinical presentations and prognosis. The use of new molecular, histological, and clinical criteria has improved their recognition. Cutaneous B-cell and T-cell lymphomas are seldom found together in the same patient. Here we report a rare case of mycosis fungoides variant of a cutaneous T-cell lymphoma (CTCL) which later developed Epstein-Barr virus (EBV) associated cutaneous B-cell lymphoproliferative disorder. The patient initially presented with generalized erythroderma, extensive plaques, and axillary lymphadenopathy. Histopathology and immunophenotyping of her tumor from the right breast nodule revealed a T-cell lymphoma consistent with mycosis fungoides. She was initially treated with pentostatin, followed by topical mechlorethamine and topical steroids. After progression of her mycosis fungoides with worsening diffuse skin lesions on this regimen, her treatments were changed to oral bexarotene with an initial partial response followed by stable disease. Three years from her initial presentation, she developed ulcerated cauliflower-like nodules on her forehead. Biopsy of these lesions revealed EBV-positive large- and medium-sized pleomorphic B-cells consistent with EBV-driven B-cell lymphoproliferative disorder. She was treated with topical acyclovir cream on the involved skin areas while continuing with oral bexarotene for mycosis fungoides. Skin lesions gradually diminished and totally disappeared after four weeks of topical acyclovir treatment. Bexarotene treatment was continued for another year until the mycosis fungoides progressed and became wide spread causing her death four and a half years after the initial diagnosis. The coexistence of two cutaneous non-Hodgkin lymphomas of different lineage in the same patient and the complete clinical response of EBV-related B-cell cutaneous component to topical acyclovir makes this rare case particularly interesting.     

The World Health Organization classification of malignant lymphoma: incidence and clinical prognosis in HTLV-1-endemic area of Fukuoka

New insights into the pathogenesis of lymphoid malignancies have been gained through novel genetic, molecular and immunological techniques. A new classification system for lymphoid malignancies, known as the new World Health Organization (WHO) classification, has been proposed recently based on these findings. The relative incidence of the subtypes of malignant lymphoma is known to differ according to geographic location. Adult T-cell leukemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukemia virus type 1 (HTLV-1), and the Kyushu islands are an HTLV-1 endemic area. To clarify the relationship between the histological classification and prognosis of lymphoid malignancies, we reclassified previous cases in our department and summarized our previous reports using the WHO classification. Of 933 cases of lymphoid malignancies, 471 (50%) were B-cell lymphoma, 396 (42%) T/natural killer (NK)-cell lymphoma and 41 (4%) Hodgkin lymphoma (HL). Analysis of clinical outcome showed favorable prognosis for HL, intermediate for B-cell lymphoma and poor prognosis for T-cell lymphoma. Among B-cell lymphomas, the commonest type was diffuse large B-cell lymphoma (n = 281; 60%). Marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) was diagnosed in 82 cases (17%), follicular lymphoma in 52 (11%) and mantle cell lymphoma in 24 (5%). Other less common lymphomas were Burkitt lymphoma (n = 9; 2%) and lymphoblastic lymphoma (n = 5; 1%). Using overall survival rates, the various B-cell lymphoma types could be divided into three broad groups for prognostic purposes: (i) low-risk group comprising follicular lymphoma and MALT; (ii) intermediate-risk group comprising diffuse large B-cell lymphoma and Burkitt lymphoma; and (iii) high-risk group comprising mantle cell lymphoma and lymphoblastic lymphoma. Among the T/NK-cell lymphomas, the commonest type was ATLL (n = 191; 48%), followed by peripheral T-cell lymphoma, unspecified (n = 83; 21%), angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) (n = 38; 10%), anaplastic large cell lymphoma (ALCL) (n = 22; 6%). Less common types were lymphoblastic lymphoma (n = 17; 4%), nasal and nasal-type NK/T-cell lymphoma (n = 17; 4%), mycosis fungoides (MF) (n = 9; 2%) and other rare types. With respect to clinical prognosis, T/NK-cell lymphomas fell into three groups: (i) relative low-risk group comprising ALCL, AILD, MF and lymphoblastic lymphoma; (ii) relative intermediate-risk group comprising NK/T-cell lymphoma and unspecified lymphoma; and (iii) extremely high-risk group comprising ATLL. Among the lymphoblastic lymphomas, B-cell type and T-cell type lymphomas exhibited different clinical outcomes. We conclude that the histological, phenotypic and genotypic classification of the new WHO system should be beneficial for the clinical approach to these tumors.     

Phenotypic analysis of peripheral T/NK cell lymphoma: study of 408 Japanese cases with special reference to their anatomical sites

The World Health Organization (WHO) classification of malignant lymphoma presented a list of disease entities well defined by clinical, immunological and genetic features. Therefore, the current diagnosis of peripheral T/NK-cell lymphomas (PTNKLs) essentially requires the inclusion of anatomical sites of disease and phenotypical features. We analyzed 408 Japanese cases of PTNKLs in order to clarify the relationship between anatomical sites of disease and phenotypical features and to translate the functional subsets of T and NK cells into their diagnoses for further understanding lymphomatic biology. The T/NK-cell lymphoma entities were allocated into three categories: (i) cytotoxic memory T-cell and/or NK-cell lymphoma (n = 151) consisting of extranodal NK/T-cell tumors other than mycosis fungoides (MF); (ii) non-cytotoxic memory T-cell lymphoma (n = 142) consisting of nodal and cutaneous tumors such as angioimmunoblastic T-cell lymphoma, adult T-cell lymphoma/leukemia and MF; and (iii) anaplastic lymphoma kinase positive anaplastic large cell lymphoma (n = 110) that has unique features and might be regarded as cytotoxic 'naive' T-cell lymphoma. Overall, these three categories were significantly correlated with age of onset, anatomical sites, the level of expression of cytotoxic molecules and CD45RO, and association with Epstein-Barr virus. This concept might provide a new insight enabling further understanding of the interrelationships among WHO T/NK-cell disease entities.     

Leu-M1 antigen expression in T-cell neoplasia.

The Leu-M1 antigen has been recently proposed as a valuable immunodiagnostic marker of the Reed-Sternberg cells of Hodgkin's disease and to be particularly helpful is distinguishing Hodgkin's disease from other lymphoproliferative disorders such as peripheral T-cell lymphomas. In this study, the authors examined paraffin-embedded tissue sections obtained from 38 patients with previously well-characterized T-cell neoplasms for the presence of the Leu-M1 antigen. The cases comprised a spectrum of T-cell malignancies and were divided into four broad clinicopathologic groups: lymphoblastic lymphoma/ leukemias (6), mature T-cell leukemias (3), peripheral T-cell lymphomas (11), and cutaneous T-cell lymphomas (18), which included both mycosis fungoides and nonmycosis fungoides types. The neoplastic T cells in 19 patients (50%) expressed the Leu-M1 antigen. The proportion of Leu-M1-positive cells and the immunostaining pattern varied greatly among these cases but correlated with mature, postthymic stages of T-cell differentiation and activation. Of particular significance was the observation that the more pleomorphic neoplastic T cells, including Reed-Sternberg-like cells, exhibited an intense cytoplasmic and membranous staining pattern which was often indistinguishable from the immunostaining pattern observed in Hodgkin's disease. The authors conclude that Leu-M1 is not a specific immunodiagnostic marker of Hodgkin's disease and has limited value in distinguishing Hodgkin's disease from T-cell neoplasms which stimulate Hodgkin's disease morphologically.     

T-cell lymphoma: morphology, immunophenotype and clinical features

The histology, immunophenotype and clinical presentation of 43 cases of T-cell lymphoma are described. Cases were classified into nine types; T-lymphocytic lymphoma (three), mycosis fungoides (six), Sézary syndrome (two), T-zone lymphoma (13), angioimmunoblastic lymphadenopathy (AIL)-like T-cell lymphoma (five), pleomorphic medium cell (one), large cell immunoblastic (four), large cell polylobated (five) and lymphoblastic (four). The patients comprised 26 males and 17 females aged between 15 and 86 years. The majority showed disseminated disease at the time of diagnosis (18 stage IV, nine stage III, five stage II, eight stage I and three cases not staged). Thirty-one patients showed lymph node involvement. Cutaneous involvement was a common finding (18 cases, 10 cases excluding mycosis fungoides and Sézary syndrome). Details of therapy and clinical follow-up were obtained in 37 cases. With simple chemotherapy only one complete response (7%, 1/16) was obtained. With aggressive therapy 48% (13/27) of patients showed complete responses. Twenty patients died during the follow-up period. Life table analysis showed a 58% probability of surviving 1 year and 36% probability of surviving 3 years. There was a significant difference in survival probability between low/intermediate-grade (lymphocytic, Sézary syndrome, mycosis fungoides and T-zone lymphoma including AIL-type) lymphomas and high-grade (large cell immunoblastic and polylobated and lymphoblastic) lymphomas (P less than 0.025). However, when survival of T-zone and AIL-like T-cell lymphoma was compared with survival of large cell immunoblastic and polylobated lymphomas no significant difference was detected. Age (less than 50 years) and stage I or II disease were associated with significantly better survival (P less than 0.005 and P less than 0.05).     

Malignant lymphomas in Korea

A retrospective histological study of 540 malignant lymphomas diagnosed at the Department of Pathology of the Seoul National University from 1976 through 1986 is presented. Malignant lymphoma is the 10th most common malignant tumor in Korea, comprising 3.07% of all malignancy during period of study. Among malignant lymphomas non-Hodgkin's lymphoma accounted for 82% and accordingly the Hodgkin's disease was for 18%. The most common type of non-Hodgkin's lymphoma was diffuse histiocytic lymphoma of Rappaport. Follicular lymphoma was very rare, comprising only 2.3%. T-cell lymphoma accounted for 9.6% of non-Hodgkin's lymphomas, the most frequent type being lymphoblastic lymphoma. Immunoblastic sarcoma and mycosis fungoides were occasionally seen but there was no case of pleomorphic adult T-cell lymphoma. Among Hodgkin's diseases, mixed cellularity type was the most common type, and nodular sclerosis type was relatively rare.     

TIA-1 expression in lymphoid neoplasms. Identification of subsets with cytotoxic T lymphocyte or natural killer cell differentiation.

TIA-I is a 15-kd cytotoxic granule-associated protein expressed in natural killer (NK) cells and cytotoxic T lymphocytes. TIA-1 expression was evaluated by paraffin immunohistochemistry in 115 T- or NK-cell neoplasms, 45 B-cell neoplasms, and 45 Hodgkin''s lymphomas. TIA-1-positive granules were identified within the cytoplasm of neoplastic cells in 6/6 large granular lymphocytic leukemias, 11/11 hepatosplenic T-cell lymphomas, 15/15 intestinal T-cell lymphomas, 6/6 NK-like T-cell lymphomas of no special type, 2/2 NK-cell lymphomas, 8/9 nasal T/NK-cell lymphomas, 7/8 subcutaneous T-cell lymphomas, 4/5 pulmonary T- or NK-cell angiocentric lymphomas (lymphomatoid granulomatosis), 12/19 T-cell anaplastic large-cell lymphomas, 2/12 nodal peripheral T-cell lymphomas, 1/3 CD8+ cutaneous T-cell lymphomas, and 5/38 classical Hodgkin''s disease. All B-cell neoplasms, nodular lymphocyte-predominant Hodgkin''s disease (7 cases), CD4+ cutaneous T-cell lymphomas (6 cases), adult T-cell leukemia/lymphomas (3 cases), T-cell chronic or prolymphocytic leukemias (3 cases), and T-cell lymphoblastic leukemia/lymphomas (7-cases) were TIA-1 negative. These findings indicate that most large granular lymphocytic leukemias, hepatosplenic T-cell lymphomas, intestinal T-cell lymphomas, NK-like T-cell lymphomas, NK-cell lymphomas, nasal T/NK-cell lymphomas, subcutaneous T-cell lymphomas, pulmonary angiocentric lymphomas of T or NK phenotype, and anaplastic large-cell lymphomas are cytotoxic T-or NK-cell neoplasms.     

Cadherins in reactive lymph nodes and lymphomas: high expression in anaplastic large cell lymphomas

Using a polyclonal pan-cadherin antibody and a monoclonal E-cadherin antibody (HECD-1) we have investigated cadherin expression in lymphomas and reactive lymph nodes. Routinely processed tissue from nine reactive lymph nodes and 48 lymphomas (six T-cell, six high-grade B-cell, 15 low-grade B-cell, 13 anaplastic large cell and eight Hodgkin's disease) were immunostained. The reactive cases showed pan-cadherin membrane associated staining of endothelium and epithelioid granulomas. No staining of lymphoid cells was seen. Pan-cadherin immunostaining was present in three of six T-cell lymphomas, two of six high-grade B-cell lymphomas, 12 of 13 anaplastic large cell lymphomas and three of eight cases of Hodgkin's disease. No staining of low-grade B-cell lymphomas was identified with the pan-cadherin antibody. E-cadherin was not detected in any of the lymphomas that showed pan-cadherin expression. The frequent and strongest cadherin expression in anaplastic large cell is noteworthy. The tumour cells of this lymphoma subtype are characterized by copious cytoplasm and a cohesive appearance, features which impart a superficial resemblance to carcinoma cells. Since cadherin molecules are known to have major morpho-regulatory functions our data suggests that the expression of cadherin molecules by anaplastic large cell lymphomas may play an important role in determining their characteristic epithelioid phenotype.     

Apoptotic rate in peripheral T-cell lymphomas. A study using a tissue microarray with validation on full tissue sections

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of non-Hodgkin lymphomas with a wide spectrum of clinicopathologic features, and apoptosis mechanisms may have a role in lymphomagenesis. We assessed apoptotic rate (AR) in 112 PTCLs using a tissue microarray developed in our laboratory and a modified terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The mean AR was 1.47% +/- 1.38% for the entire group of PTCLs (range, 0.06%-5.15%), and AR varied significantly among different tumor types. In mycosis fungoides, the mean AR was 0.74%; angioimmunoblastic T-cell lymphoma, 1.02%; PTCL, not otherwise specified, 1.38%; cutaneous anaplastic large cell lymphoma (ALCL), 1.41%; anaplastic lymphoma kinase protein (ALK)-negative ALCL, 1.43%; extranodal natural killer/T-cell lymphoma of nasal type, 2.04%; ALK-positive ALCL, 2.95%; and enteropathy-type T-cell lymphoma, 3.06%. Mean AR was higher in PTCL with large cell vs small/medium cell morphologic features (1.66% +/- 1.1% vs 0.99% +/- 1.0%). In a subset of 33 PTCLs, the tissue microarray results comparedfavorably with those obtained in full tissue sections. We conclude that the highest ARs in PTCLs are found in enteropathy-type T-cell lymphoma and ALK-positive ALCL, and that AR can be assessed reliably by using a tissue microarray.