Vitreoretinal Lymphoma as the Initial Presentation of a Breast Diffuse Large B-cell Lymphoma.

Purpose: We report a case of vitreoretinal lymphoma as the initial presentation of diffuse large B-cell lymphoma of the breast. Methods: A case report is presented. Results: A 72-year-old woman was referred for evaluation of vitritis in both eyes. Diagnostic vitrectomy and pathology workup demonstrated atypical lymphoid cells consistent with the presence of diffuse large B-cell lymphoma. Brain magnetic resonance imaging and lumbar puncture findings were negative for central nervous system lymphoma. Positron emission tomography/computed tomography imaging showed a mass in the left breast, and breast biopsy confirmed aggressive B-cell lymphoma. Conclusions: When vitreoretinal lymphoma is diagnosed, it is important to evaluate for other forms of systemic lymphoma in addition to central nervous system lymphoma.

Natural killer/T-cell lymphoma invading the orbit and globe.

Natural killer/T-cell lymphomas are extremely rare and carry high mortality rates. Epidemiologically, these cancers tend to affect mainly Asian and South American patients and are associated with Epstein-Barr virus seropositivity. This report details a 78-year-old Vietnamese woman who presented initially with vitritis of unknown cause, but later developed proptosis and conjunctival involvement as her disease spread. Biopsies of the orbit, ethmoid sinus, and conjunctiva were found to be significant for natural killer/T-cell lymphoma. The case highlights the diagnostic difficulty of this tumor given its rarity and ability to mimic other disorders.

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoproliferative disorder: Report of a case and review of the literature.

Primary cutaneous small/medium-sized T-cell lymphoma (PCSM-TCL), which was included in the World Health Organization - European Organization for Research and Treatment of Cancer (WHO-EORTC) classification for cutaneous lymphomas as a provisional entity in 2008, has recently been reclassified as primary cutaneous small/medium-sized T-cell lymphoproliferative disorder (PCSM-TCLPD) because of its indolent behavior and uncertain malignant potential. Treatment with local therapies is usually curative, although there have been reports of aggressive, systemic disease. This spectrum of disease behavior evokes the consideration that this entity may actually be multiple diseases with a shared clinicopathologic features rather than a singular disease process with a variety of behaviors. PCSM-TCLPD retained its designation as a provisional entity under the updated WHO-EORTC guidelines; however, additional cases of PCSM-TCLPD are needed to shed more light on this rare disorder.

T-cell receptor signaling in peripheral T-cell lymphoma - a review of patterns of alterations in a central growth regulatory pathway.

T-cell receptor (TCR) signaling is pivotal in T-cell development and function. In peripheral T-cell lymphomas/leukemias (PTCL/L), histogenesis, transforming events, epidemiology, and clinical presentation are also closely linked to TCR-mediated influences. After reviewing the physiology of normal TCR signaling and cellular responses, we describe here the association of subgroups of PTCL/L with specific patterns of TCR activation as relevant tumor-initiating and/or tumor-sustaining programs. We identify PTCL/L with a functionally intact TCR machinery in which stimulation is possibly incited by exogenous antigens or autoantigens. Distinct from these are tumors with autonomous oncogenic signaling by dysregulated TCR components uncoupled from extrinsic receptor input. A further subset is characterized by transforming events that activate molecules acting as substitutes for TCR signaling, but triggering similar downstream cascades. We finally discuss the consequences of such a functional model for TCR-targeted therapeutic strategies including those that are being tested in the clinic and those that still require further development.

Immunohistochemical detection of ZAP70 in chronic lymphocytic leukemia predicts immunoglobulin heavy chain gene mutation status and time to progression.

Zeta-associated protein-70 (ZAP70) expression measured by flow cytometry has been proposed as a surrogate marker of the somatic mutation status of the immunoglobulin heavy chain variable region (IGHV) genes in chronic lymphocytic leukemia. However, attempts to implement this approach in clinical flow cytometry laboratories have been problematic; many commercially available antibodies give unreliable results. Assessment of ZAP70 protein expression by immunohistochemistry in chronic lymphocytic leukemia tissue sections is an easy, alternative approach, although lack of quantitation and subjective interpretation of results are potential pitfalls. In this study, we correlated ZAP70 protein expression, assessed by immunohistochemistry, with ZAP70 messenger RNA (mRNA) transcript expression, assessed by semi-quantitative real-time reverse transcriptase-polymerase chain reaction assay, with the somatic mutation status of the IGHV genes in previously untreated patients with chronic lymphocytic leukemia. Expression of ZAP70 protein and mRNA transcripts correlated strongly (P=8.238 × 10(-12)). Expression of ZAP70 protein and mRNA transcripts also correlated strongly with the somatic mutation status of the IGHV genes (P=0.000071 and P=0.00076, respectively). Further, ZAP70 positivity by immunohistochemistry was associated with an increased risk of progression to therapy requirement (3-year risk 83% vs 31% for ZAP70 negative by immunohistochemistry, P=0.03). These results show that ZAP70 expression assessed by immunohistochemistry is a reliable surrogate marker of the somatic mutation status of the IGHV genes, and predicts time to progression.

p53 expression by immunohistochemistry is an important determinant of survival in patients with chronic lymphocytic leukemia receiving frontline chemo-immunotherapy.

Although chromosome 17p abnormalities and TP53 mutations have been reported as poor prognostic indicators in chronic lymphocytic leukemia (CLL), the impact of aberrant p53 expression as assessed by immunohistochemistry (p53-IHC) has not been defined in patients with CLL treated with chemoimmunotherapy, particularly in the context of other novel markers such as ZAP-70 expression and IgVH mutation status (IgVH MS). We assessed p53-IHC in 222 bone marrow (BM) specimens from patients with CLL enrolled in a phase II trial with fludarabine, cyclophosphamide, and rituximab (FCR). ZAP70 expression and IgVH MS were assessed in 208 and 108 patients, respectively. One hundred sixty-eight patients had concurrent classical cytogenetic analysis. p53-IHC correlated with abnormal karyotype (p = 0.002) and adversely affected overall survival independent of ZAP70 expression and IgVH MS (p < 0.001). Patients with p53-IHC(+) CLL were less likely to achieve complete remission, but patients who did achieve complete remission showed a durable response. In this patient cohort, p53-IHC is an important determinant of complete remission and overall survival, but not remission duration, in patients with CLL receiving FCR.

Graft-versus-leukaemia effect after non-myeloablative haematopoietic transplantation can overcome the unfavourable expression of ZAP-70 in refractory chronic lymphocytic leukaemia.

ZAP-70 (zeta-chain-associated protein 70 kDa) expression is associated with poor prognosis in patients with chronic lymphocytic leukaemia (CLL). This study evaluated the efficacy of non-myeloablative allogeneic stem cell transplantation in patients with advanced CLL and assessed the impact of ZAP-70 expression on the outcome. Thirty-nine sequential patients were included. All had previously been treated with fludarabine. All patients received a preparative regimen of fludarabine (30 mg/m(2)/d for 3 d), intravenous cyclophosphamide (750 mg/m(2)/d for 3 d), and high-dose rituximab. Immunohistochemical techniques on marrow biopsy samples were used to determine that ZAP-70 was expressed in 25 patients, whereas 13 other patients were ZAP-70 negative, and one was of indeterminate status. With a median follow-up time of 27 months, the estimated overall survival and current progression-free survival (CPFS) rates at 4 years were 48% and 44% respectively. Patients who were ZAP-70 positive had 56% survival, and their CPFS rate increased from 30% to 53% after a donor lymphocyte infusion. Multivariate analysis indicated that chemorefractory disease and mixed T cell chimerism at day 90, but not ZAP-70 positivity, were associated with the risk of disease progression after transplantation. These results demonstrate a potent graft-versus-leukaemia effect that can overcome the adverse prognostic effect of ZAP-70 expression.

Follicular dendritic cell sarcoma: a report of 14 cases and a review of the literature.

Follicular dendritic cell sarcomas (FDCS) are grouped with the histiocytic and dendritic cell neoplasms. The natural history and response to different treatments have not been well established. The cases of 14 patients with FDCS who were seen at M. D. Anderson between 1995 and 2005 were reviewed. Median patient age was 48 years (range, 25-69 years). Histologically, four cases showed low-grade features, three cases showed low-grade features with focal high-grade features, and five cases showed high-grade features. Tumors were positive for CD21, CD23, and CD35 in 83, 90, and 44% of cases, respectively. Twelve (92%) of 13 tumors were strongly positive for epidermal growth factor receptor. Information on initial treatment was available in 11 patients, which included surgery alone in one patient, surgery and radiation in two, surgery and chemotherapy in one, chemotherapy alone in three, chemotherapy and radiation in one, surgery followed by radiation and chemotherapy in three patients. In eight patients the initial chemotherapy regimen was cyclophosphamide, doxorubicin, vincristine, and prednisone. Complete remission was achieved in 7 (63%) of 11 patients. Ten patients were alive at a median follow up of 22 months, 3 (23%) of 13 had no evidence of disease, and 7 (53%) of 13 patients were alive with disease. Follicular sarcoma is an aggressive neoplasm. Although most of the patients initially responded to treatment, the majority of them (81%) relapsed. A better understanding of the biology of FDCS could guide our efforts in the development of new treatment modalities for this rare disease.

Mediastinal follicular dendritic cell sarcoma involving bone marrow: a case report and review of the literature.

We report a rare case of mediastinal follicular dendritic cell (FDC) sarcoma involving the bone marrow. The patient, a 46-year-old woman, had a clinically aggressive tumor in the anterior mediastinum that was initially diagnosed as a diffuse B-cell lymphoma. She received chemotherapy but showed no significant improvement. One year later, the patient presented at our institution with pelvic bone metastases. Biopsy specimens of the sacrum lesion and bone marrow were obtained. The diagnosis of FDC sarcoma was made based on histological examination and immunohistochemical findings, including strong positive staining of tumor cells for CD21, CD23, clusterin, and epidermal growth factor receptor (EGFR) and negative staining for CD20, CD30, CD45, CD1a, S-100, vimentin, and keratin cocktail. Histological examination and immunohistochemical studies of a previous biopsy of the mediastinal mass confirmed the diagnosis of mediastinal FDC sarcoma. The patient was treated with an appropriate chemotherapy regimen; 1 month later, follow-up bone marrow biopsy revealed no tumor cells. Although FDC sarcoma is considered a low-grade tumor, the tumor in the present case not only developed at an unusual location with bone metastasis but also involved bone marrow. To our knowledge, this is the first such case ever reported. This case also highlights the utility of EGFR as an immunohistochemical marker of dendritic cell tumors that could be used as a diagnostic tool and guide for choosing appropriate chemotherapy regimens.

MALT1 gene rearrangements and NF-kappaB activation involving p65 and p50 are absent or rare in primary MALT lymphomas of the breast.

Mucosa associated lymphoid tissue (MALT) lymphomas arising in the breast are uncommon and few cases have been assessed for MALT lymphoma-associated translocations, BCL-10 expression, or NF-kappaB activation. In this study, we analyzed eight cases of primary breast MALT lymphoma. We also included 14 cases of primary breast diffuse large B-cell lymphoma since some of these may represent transformation of MALT lymphoma, known to occur at extra-mammary MALT sites. All cases were assessed for MALT1 gene rearrangements by fluorescence in situ hybridization (FISH). Using immunohistochemical methods, all cases were assessed for BCL-10, and subsets were assessed for NF-kappaB p65 and p50. None of the cases had MALT1 gene rearrangements by FISH. Of eight MALT lymphomas, BCL-10 was positive in seven (88%), with moderate nuclear and cytoplasmic staining in six, and a weak cytoplasmic staining in one. NF-kappaB p65 (n=8) and p50 (n=5) were negative or showed only cytoplasmic staining (ie inactivated) in all cases. Of 14 diffuse large B-cell lymphoma cases, BCL-10 was positive in 12 (87%), with weak-to-moderate cytoplasmic staining in 10, weak cytoplasmic and focally nuclear staining in one, and a moderate-to-strong nuclear and cytoplasmic staining in one. NF-kappaB p65 (n=11) showed cytoplasmic staining in all cases, whereas p50 (n=8) showed nuclear positivity (ie activated) in two (25%) cases. We conclude that MALT1 gene rearrangements are absent or rare in primary breast MALT lymphoma and diffuse large B-cell lymphoma. In MALT lymphomas, the moderate BCL-10 nuclear expression in six neoplasms is inconsistent with the FISH results, suggesting that BCL-10 immunostaining overestimates the frequency of MALT1 gene rearrangements. We also could not demonstrate NF-kappaB activation using nuclear staining for p65 and p50. In contrast, breast diffuse large B-cell lymphomas are heterogeneous. Weak cytoplasmic BCL-10 staining in most cases and evidence of NF-kappaB p50 activation in a subset differs from breast MALT lymphomas.

Myeloid sarcoma involving the testis.

Myeloid sarcoma is a neoplasm of immature granulocytes, monocytes, or both involving any extramedullary site. Myeloid sarcoma involving the testis, however, is uncommon and very rarely occurs as an isolated mass. We describe 4 patients with myeloid sarcoma involving the testis, including 2 patients in whom the neoplasm was isolated to the testis (1 unilateral and 1 bilateral). Histologically, 4 neoplasms were poorly differentiated and 1 was blastic. Each neoplasm was shown to be of myeloid lineage, and negative for T- and B-cell specific antigens using immunohistochemical methods. One case was also positive for chloroacetate esterase. In the literature, most cases of myeloid sarcoma involving the testis represent relapse or the initial presentation of acute myeloid leukemia. Including the 2 cases we report here, only 7 cases of myeloid sarcoma isolated to the testis have been reported.

Hodgkin lymphoma involving Waldeyer ring: a clinicopathologic study of 22 cases.

We report 22 cases of Hodgkin lymphoma involving Waldeyer ring seen at our institution during a 31-year interval. There were 16 males (73%) and 6 females (27%) with a median age of 48 years (range, 5-81 years), and 15 (68%) patients had airway obstruction or tonsillar enlargement. For 19 patients, the clinical stage was as follows: I, 7 (32%); II, 11 (50%); and III, 1 (5%). The 3 patients (14%) whose disease was unstaged had concurrent or a history of non-Hodgkin lymphoma. Histologically, the neoplasms were classified as follows: lymphocyte-rich classical, 8 (36%); nodular sclerosis, 7 (32%); mixed cellularity, 4 (18%); unclassified, 2 (9%); and lymphocyte depletion, 1 (5%). Of 7 stage I cases, 4 (57%) were the lymphocyte-rich classical type. Reed-Sternberg and Hodgkin cells were positive for CD15 and CD30 in 20 cases assessed. Epstein-Barr virus latent membrane protein type 1 was positive in 12 (67%) of 18 cases assessed. We conclude that Hodgkin lymphoma rarely involves Waldeyer ring, with the lymphocyte-rich classical type being common at this location.

Chronic lymphocytic leukemia/small lymphocytic lymphoma associated with IgM paraprotein.

We studied the clinicopathologic, immunophenotypic, and cytogenetic features of 26 patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) associated with serum IgM paraprotein. The study group (16 men; 10 women; median age, 64 years; range, 40-82 years) represents approximately 2.5% of CLL/SLL cases at our institution. The paraprotein level ranged from 1 to 14 g/L (median, 4 g/L). Neoplasms in bone marrow were composed of small round lymphocytes arranged in nodular (n = 6), diffuse (n = 5), interstitial (n = 5), or mixed (n = 10) patterns. All cases were positive for monotypic surface immunoglobulin light chain, IgM/IgD, CD5, CD19, CD20, and CD23. CD11c (14/20 [70%]), CD79b (11/19 [58%]), FMC-7 (11/26 [42%]), CD22 (8/20 [40%]), and ZAP-70 (6/19 [32%]) were expressed in subsets of cases. Of 17 bone marrow specimens assessed by conventional cytogenetics, 6 were abnormal and 11 were diploid. The overall survival of this group (median follow-up, 24 months) was not significantly different from that for an age-, sex-and stage-matched group of 52 CLL/SLL patients without IgM paraprotein (P = .60). We conclude that CLL/SLL cases with serum IgM paraprotein are similar to other CLL/SLL cases in their clinicopathologic and immunophenotypic features.

T-cell prolymphocytic leukemia involving extramedullary sites.

T-cell prolymphocytic leukemia (T-PLL) can involve extramedullary sites, but the diagnosis is usually established by examination of blood and bone marrow. As a result, the histologic findings at extramedullary sites are poorly documented in the literature. We describe 19 extramedullary biopsy specimens from 14 patients with T-PLL. Skin (n = 10) was the most common site biopsied. T-PLL surrounded dermal blood vessels and appendages (n = 6), diffusely replaced dermis (n = 3), or formed a subcutaneous mass (n = 1). Other extramedullary sites included liver and lymph nodes (3 each) and spleen, lung, and cecum (1 each). In liver and lymph nodes, the neoplasm predominantly involved portal tracts and paracortex, respectively. Cytologically, the T-PLL cells were round (n = 16) or Sezary cell-like (n = 3). Nucleoli were observed in a subset of cells in 8 specimens and were prominent in 3 specimens. Immunostaining for T-cell leukemia-1 (TCL-1) was positive in specimens from 9 (64%) of 14 patients. We conclude that the prolymphocytoid features of T-PLL cells can be difficult to detect in routinely stained sections of extramedullary biopsy specimens. TCL-1 expression can aid in diagnosis at extramedullary sites.

Myeloid sarcoma involving the breast.

CONTEXT: Myeloid sarcoma is a neoplasm of myeloid cells that can arise before, concurrent with, or following acute myeloid leukemia. Rarely, it can also occur as an isolated mass. OBJECTIVE: To describe the clinicopathologic features of 6 patients with myeloid sarcoma involving the breast. DESIGN: Clinical information for all 6 patients was obtained from the medical record. Routine hematoxylin-eosin-stained slides; naphthol AS-D chloroacetate stain; and immunohistochemical stains for myeloid, B-cell, and T-cell antigens were prepared. RESULTS: There were 6 women with a median age of 52 years (range, 31-73 years). Two patients presented with isolated tumors of the breast, with no history or subsequent development of acute myeloid leukemia. In 3 patients, the breast tumors represented relapse of acute myeloid leukemia. One patient who presented initially with myeloid sarcoma involving the breast, skin, and spleen was lost to follow-up. Histologically, these tumors were classified as well differentiated (n = 3), poorly differentiated (n = 2), and blastic (n = 1). Naphthol AS-D chloroacetate esterase was positive in all 3 cases assessed. Immunohistochemistry showed that myeloperoxidase (n = 5) and CD43 (n = 3) were positive, and CD3 (n = 5) and CD20 (n = 5) were negative in all cases assessed. Lysozyme was positive in 4 (80%) of 5; CD117 was positive in 2 (67%) of 3; and single cases were positive for CD45 (1/3), TdT (1/2), CD79a, and the PAX5 gene product. CONCLUSIONS: Myeloid sarcoma involving the breast is uncommon. In the literature, as in this study, these tumors most often represent relapse or the initial presentation of acute myeloid leukemia. However, 2 of the cases we report presented with isolated masses, without a history or subsequent development of acute myeloid leukemia at last follow-up. Immunohistochemical studies are extremely helpful for recognizing isolated myeloid sarcoma.

MCL-1 expression in B-cell non-Hodgkin's lymphomas.

B-cell non-Hodgkin's lymphomas are known to express BCL-2 family proteins, of which the myeloid cell leukemia-1 (MCL-1) protein is a member. MCL-1 is involved in viability and immortalization of normal and neoplastic B cells, and expression is regulated transcriptionally and posttranscriptionally, resulting in an anti-apoptotic (full length) or a pro-apoptotic (short isoform) gene product. In this study, we assessed 151 B-cell lymphomas for MCL-1 expression and analyzed for expression of the full-length and short isoforms of MCL-1 in B-cell lymphoma cell lines. By using immunohistochemistry, a subset of neoplasms in 9 lymphoma types studied expressed MCL-1, but expression was more frequent and intense in high-grade (43 of 49, 88%) compared with low-grade (34 of 92, 37%) lymphomas (P < 0.0001). In follicular lymphomas, MCL-1 expression positively correlated with increasing grade; 1 (14%) of eight grade 1, 7 (70%) of ten grade 2, and all 9 (100%) grade 3 were positive (P < 0.0008). All plasma cell myeloma cases assessed were also MCL-1 positive. By using Western blot analysis, 6 of 7 high-grade B-cell lymphoma cell lines showed predominant expression of full-length MCL-1, compared with no or weak expression of the short isoform. One myeloma and 1 of 2 mantle cell lymphoma cell lines also tested showed only full-length isoform expression. Our data suggest that MCL-1 is frequently expressed in high-grade B-cell lymphomas and plasma cell myeloma, most likely in its full-length isoform that is an active anti-apoptotic gene product. MCL-1 expression also correlates with grade and may contribute to transformation in follicular lymphomas.

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.

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.