John B. Cousar

Hepatosplenic αβ T-cell lyrnphomas: A report of 14 cases and comparison with hepatosplenic γδ T-cell lymphomas

Hepatosplenic gammadelta T-cell lymphoma is a distinct entity, characterized by occurrence in young adult males with hepatosplenomegaly, B-symptoms, peripheral blood cytopenias, and no lymphadenopathy; lymphomatous infiltrates in the splenic red pulp, hepatic sinusoids, and bone marrow sinuses; T-cell receptor (TCR) gammadelta chains and a cytotoxic T-cell phenotype; isochromosome 7q; and an aggressive clinical course. In comparison, this study describes the clinicopathologic features of 14 hepatosplenic T-cell lymphomas expressing TCR alphabeta chains. They occurred in 11 women and 3 men with a median age of 36 years. Clinical presentation was similar to that described previously for hepatosplenic gammadelta T-cell lymphomas, except for the female preponderance and age distribution (5 patients younger than 13 years of age and 5 patients older than 50 years of age). Disease distribution was primarily in the splenic red pulp and hepatic sinusoids, although liver infiltrates were largely periportal in four cases. Bone marrow involvement, observed in eight patients, was usually interstitial and/or within the sinuses. Lymph nodes were involved in five patients, although lymphadenopathy was demonstrable in only two. Ten cases were composed of intermediate-size tumor cells with round/oval nuclei, slightly dispersed chromatin, inconspicuous nucleoli, and scant to moderate amounts of cytoplasm. Four lymphomas contained primarily large cells with irregular nuclei, dispersed chromatin, discernible nucleoli, and moderate to abundant cytoplasm. Tumor cells in all 14 lymphomas were cytotoxic alphabeta T-cells; 13 co-expressed natural killer cell-associated antigens and showed T-cell clonality. Three lymphomas were associated with Epstein-Barr virus. Two of four cases had an isochromosome 7q. Eleven patients are dead, eight within a year of diagnosis, and two patients have maintained complete remissions after combination chemotherapy. These data show that hepatosplenic T-cell lymphomas include an alphabeta-subtype. This group, along with the previously recognized gammadelta group, should be recognized as phenotypically heterogeneous subtypes of the same disease entity.

Peripheral T-cell lymphoma: a clinicopathologic study of 42 cases.

Clinical and histopathologic material from 42 patients with peripheral T-cell lymphoma (PTCL) was reviewed. The median age was 63.5 years (range, 11-97 years). The male:female ratio was 2.8:1. Prior immune or lymphoproliferative diseases occurred in 36% of the patients. PTCL was advanced at presentation with B symptoms (67%), generalized adenopathy (69%), and stage III/IV disease (79%). Suspected lung or pleural involvement (21%), hepatomegaly (29%), and splenomegaly (43%) were common; marrow involvement was documented in 37% of the patients at presentation and in 51% of patients during the illness. Hypercalcemia and eosinophilia occurred in 19% and 29% of patients, respectively. Among patients receiving combination chemotherapy (BCOP, CHOP, BACOP, COMLA), eight (24%) of 33 achieved a complete remission and only four (12%) of 33 had a sustained complete remission. The median survival for PTCL was 11 months. Because of the poor response to standard therapy, clinical trials should identify cases of PTCL and evaluate newer regimens in this subset of aggressive lymphoma.

Peripheral T-cell lymphoma

Peripheral T‐cell lymphoma is the most common type of T‐cell lymphoma seen in adults in the United States. Clinical data were reviewed from 134 cases of peripheral T‐cell lymphoma diagnosed in three centers. The median age of the patients was 57 years (range, 4‐97 years), 59% were male, and 36 patients (27%) had a history of a preceding disorder of the immune system. The tumors were grouped histologically into large cell (43%), mixed large and small cell (40%), and small cell (17%). The stage at diagnosis was I (7%), II (21%), III (22%), and IV (50%). B symptoms were present in 57%. The most frequent sites of extranodal involvement were bone marrow (35%), skin (13%), and lung (11%). Eighty patients were treated with a multiagent chemotherapy regimen with proven curative potential in aggressive non‐Hodgkins lymphomas and the remainder of the patients received less intensive chemotherapy (36 patients), radiotherapy (nine patients), or no treatment (nine patients). Fifty percent of the intensively treated patients achieved complete remission and the actuarial 4‐year survival was 45%. However, the 4‐year, disease‐free survival in patients with Stage IV disease was only 10%. Although peripheral T‐cell lymphomas appeared similar in many ways to their B‐cell counterparts, disease‐free survival by stage was low and patients with Stage IV disease had an especially poor outlook.

T-cell-rich B-cell lymphomas: A clinicopathologic study of 19 cases

T-cell-rich B-cell lymphomas (TCRBCLs) are recently described, unusual non-Hodgkins lymphomas that have a diffuse morphology, a predominance of reactive T-cells, and a minority of neoplastic B-cells. The clinical and pathological features of 19 TCRBCLs, all of which demonstrated B-cell clonality, are presented. These lymphomas generally affected older patients by widespread disease and usually were nodal in origin. Treatment varied, but continuous complete remissions (eight patients) were achieved only in those receiving chemotherapy directed at intermediate-grade lymphomas. Although morphologically heterogeneous, all cases resembled peripheral T-cell lymphomas (PTCLs); several TCRBCLs also contained Reed-Sternberg-like cells. Flow cytometry or frozensection immunoperoxidase failed to detect monotypic immunoglobulin (Ig) in eight of eight cases tested. In contrast, paraffin immunoperoxidase was very useful diagnostically, showing large L26 (CD20-associated) positive cells scattered singly or in small clusters among numerous small T-cells (UCHL1[CD45RO] positive) in all cases. Monotypic cytoplasmic Ig was present in 16 of 19 cases, one of which exhibited plasmacytic differentiation. Southern blot analysis demonstrated relatively faint Ig JH and/or JK bands, indicating a small monoclonal B-cell population in nine of 11 cases, one of which also showed a bcl-2 rearrangement. No T-cell receptor gene rearrangements were observed. These results showed that TCRBCLs may be easily confused with PTCLs or occasionally confused with Hodgkins disease. TCRBCLs are probably heterogeneous biologically; some cases are of follicular center cell origin. These lymphomas respond to chemotherapy directed at intermediate-grade lymphomas, apparently have a better prognosis than PTCLs, and seem to represent morphological variants of different types of large B-cell lymphomas.

Immunohistochemical Detection of Cyclin D1 Using Optimized Conditions Is Highly Specific for Mantle Cell Lymphoma and Hairy Cell Leukemia

Mantle cell lymphoma (MCL) is more aggressive when compared with other lymphomas composed of small, mature B lymphocytes. Cyclin D1 is overexpressed in MCL as a result of the translocation t(11;14)(q13;q32). Cyclin D1 immunohistochemistry in fixed, paraffin-embedded tissue contributes to the precise and reproducible diagnosis of MCL without the requirement of fresh tissue. However, its use in bone marrow biopsies is not well established. In addition, increased levels of cyclin D1 mRNA have been found in hairy cell leukemia but have not consistently been detected by immunohistochemistry. We used a polyclonal antibody and heat-induced antigen retrieval conditions to evaluate 73 fixed, paraffin-embedded bone marrow, spleen, and lymph node specimens with small B-cell infiltrates, obtained from 55 patients. Cyclin D1 was overexpressed in 13/13 specimens of MCL (usually strong, diffuse reactivity in most tumor cells) and in 14/14 specimens of hairy cell leukemia (usually weak, in a subpopulation of tumor cells). No reactivity was detected in five cases of B-chronic lymphocytic leukemia; five cases of splenic marginal zone lymphoma; six cases of nodal marginal zone cell lymphoma; two cases of gastric marginal zone cell lymphoma; or ten benign lymphoid infiltrates in bone marrow, spleen, or lymph nodes. In summary, although the total number of studied cases is small and a larger series of cases may be required to confirm our data, we present optimized immunohistochemical conditions for cyclin D1 in fixed, paraffin-embedded tissue that can be useful in distinguishing MCL and hairy cell leukemia from other small B-cell neoplasms and reactive lymphoid infiltrates.

Malignant lymphomas of follicular center cell origin in humans. V. incidence, clinical features, and prognostic implications of transformation of small cleaved cell nodular lymphoma

Seventy‐five cases of small cleaved cell nodular lymphoma (SCC‐N) were reviewed. Thirty‐four cases underwent repeat biopsy a median of 54 months after diagnosis (range, 7–116 months) because of progressive or recurrent disease. Histologic conversion to a transformed (noncleaved) cell lymphoma was found at re‐biopsy in 13 of 34 cases (38%). Neither age, gender, stage, visceral sites of disease, nor symptoms at presentation were predictive of subsequent conversion. Similarly, none of the clinical features analyzed at the time of rebiopsy were predictive of whether the rebiopsy would show stable histology or transformation. Documentation of transformation was of significant prognostic value. Although rebiopsies were performed at the time of progressive disease, survival following re‐biopsy was 37.5 months for patients found to have cleaved cell lymphoma at re‐biopsy, and only 2.5 months for those with transformed cell lymphoma at re‐biopsy. Two of the cases which had immunoglobulin surface markers studied at diagnosis and at transformation, showed retention of heavy and light chain markers. This implies that the change in appearance involves the original neoplastic clone and was not due to a second neoplasm. Development of transformed cell lymphoma is one of the most common features of the aggressive phase of indolent lymphoma. Repeat biopsy in all patients with indolent lymphoma who have relapsing or progressive disease is recommended. Cancer 53:1109‐1114, 1984.

Somatic mutation analysis of IgH variable regions reveals that tumor cells of most parafollicular (monocytoid) B-cell lymphoma, splenic marginal zone B-cell lymphoma, and some hairy cell leukemia are composed of memory B lymphocytes.

The cell of origin of parafollicular (monocytoid) B cell lymphoma (PBCL), splenic marginal zone lymphoma (SMZL), and hairy cell leukemia (HCL) is controversial. To better understand the relationship between these low-grade B-cell neoplasms, we analyzed the nucleotide sequences of the rearranged immunoglobulin heavy (IgH) chain variable (V) region of the clonal population of cells in five cases of PBCL, four cases of SMZL, and seven cases of HCL to determine whether these neoplasms could be differentiated by the degree of somatic mutation in the IgH V gene or by the IgH V gene family usage. DNA was extracted from diagnostic material and clonality confirmed by PCR. The DNA was reamplified using V heavy chain family specific primers, and the amplicons were sequenced. Sequences were compared with germline IgH V gene sequences, and base changes were determined to be silent or to represent amino acid replacements by using three different methods. Four of five (80%) cases of PBCL, three of four (75%) cases of SMZL, and three of seven (43%) cases of HCL showed evidence of antigen selection, suggesting that these neoplasms involved clonal expansions of postgerminal center memory lymphocytes. Only SMZL showed a preferential usage of V(H)1 family genes.

A relationship between impaired cellular immunity, humoral suppression of lymphocyte function and severity of systemic lupus erythematosus

Eighteen newly diagnosed, untreated patients with systemic lupus erythematosus (SLE) were divided into two groups based on the severity of the disease. Patients with very active disease were nonresponsive to skin test antigens used to assess delayed hypersensitivity. Skin test reactivity was intact in most patients with mildly active disease. Lymphocytes from subjects in both groups responded normally to phytohemagglutinin (PHA) when the results were expressed as counts per minute per million small lymphocytes. Serum from patients with severely active disease markedly suppressed lymphocyte responsiveness of autologous and allogeneic lymphocytes. Serum from patients with mild disease had significantly less suppressor activity. Lymphocytotoxic antibodies and suppressor activity were not correlated. Suppressor activity in immunoglobulin G fraction paralleled that found in whole serum. The present studies suggest that impaired delayed whole serum. The present studies suggest that impaired delayed hypersensitivity in SLE is a consequence of disease activity rather than an inherent feature of this disease. The strong correlation between serum suppression of PHA reactivity and anergy suggests that the humoral immunosuppressive effects described may be responsible, in part, for impaired delayed hypersensitivity in this disease.

Splenic marginal zone lymphoma. A distinct B-cell neoplasm.

The splenic marginal zone is a morphologically and perhaps immunologically distinct B-cell compartment. Lymphomas arising from cells of the splenic marginal zone are rare. Here we describe the morphologic, immunologic, and clinical features of 14 cases. Patient age ranged from 35 to 79 years (median, 68 years) with a male-to-female ratio of 1:1.8. The spleen was uniformly enlarged (median, 1,540 g; range, 388-3,845 g) in all patients, the neoplastic infiltrate had a nodular pattern in three cases, nodular and diffuse in seven cases, and diffuse in four cases. The neoplastic cells had small to medium-sized nuclei with round, oval, or slightly indented contours, small eosinophilic nucleoli, and a moderate amount of pale cytoplasm. Extrasplenic involvement was present in 12 patients. Lymph nodes often had a vaguely nodular pattern and preservation of sinuses; bone marrow was infiltrated focally (seven cases) or diffusely (one case). Five patients had hepatic involvement. Ultrastructurally, neoplastic cells differed from other small B cells and resembled normal marginal zone cells by having long, serpentine rough endoplasmic reticulum profiles. All lymphomas marked as B cells and light chain restriction was demonstrated in 12 cases. Bcl-2 protein expression was present in all cases. Most cases (70%) were negative for DBA.44 (CD72). Plasmacytic differentiation was present in three cases. In conclusion, splenic marginal zone lymphoma is a B-cell neoplasm with distinctive clinical, morphologic, immunologic, and ultrastructural characteristics.

Rituximab-CD20 Complexes Are Shaved from Z138 Mantle Cell Lymphoma Cells in Intravenous and Subcutaneous SCID Mouse Models

Infusion of standard-dose rituximab (RTX) in chronic lymphocytic leukemia (CLL) patients promotes rapid complement activation and deposition of C3 fragments on CLL B cells. However, immediately after RTX infusions, there is substantial loss (shaving) of CD20 from circulating malignant cells. Because shaving can compromise efficacies of anticancer immunotherapeutic mAbs, we investigated whether shaving occurs in SCID mouse models. Z138 cells, a B cell line derived from human mantle cell lymphoma, were infused i.v. or s.c. The i.v. model recapitulates findings we previously reported for therapeutic RTX in CLL: i.v. infused RTX rapidly binds to Z138 cells in lungs, and binding is accompanied by deposition of C3 fragments. However, within 1 h targeted cells lose bound RTX and CD20, and these shaved cells are still demonstrable 40 h after RTX infusion. Z138 cells grow in tumors at s.c. injection sites, and infusion of large amounts of RTX (0.50 mg on each of 4 days) leads to considerable loss of CD20 from these cells. Human i.v. Ig blocked shaving, suggesting that FcγRI on cells of the mononuclear phagocytic system promote shaving. Examination of frozen tumor sections from treated mice by immunofluorescence revealed large areas of B cells devoid of CD20, with CD20 intact in adjacent areas; it is likely that RTX had opsonized Z138 cells closest to capillaries, and these cells were shaved by monocyte/macrophages. The shaving reaction occurs in neoplastic B cells in tissue and in peripheral blood, and strategies to enhance therapeutic targeting and block shaving are under development.