Raul C. Braylan

Non-Endemic Burkitt's Lymphoma: A B-Cell Tumor Related to Germinal Centers

To investigate the nature of non-endemic Burkitts lymphoma, we examined neoplastic cells from eight American patients for receptors for sheep erythrocytes (E), complement (EAC), and Fc fragment of lgG (igGEA), and for surface immunoglobulins (Slg) and hydrolytic enzymes. In addition, we reviewed 47 biopsies and 17 autopsies from American patients to ascertain patterns of involvement by tumor in lymph nodes, spleens and Peyers patches. Neoplastic cells in all cases studies bore monoclonal surface immunoglobulins of the igM class. Receptors for EAC and igGEA were identified on a minority of the cells. Little or no hydrolytic enzyme activity was demonstrable. These results indicate that, like Burkitts lymphoma in Africans, this histologically identical tumor in American patients consists of B lymphocytes. In 10 biopsies and two autopsies, germinal centers were selectively involved by tumor, suggesting that these neoplastic cells may be related to some B lymphocytes of normal germinal centers.

Immunologic aspects and pathology of the malignant lymphomas

Malignant lymphomas have traditionally been classified on solely morphologic grounds. With new immunologic and cytochemical techniques, it has been possible to characterize normal cells of the T‐lymphocytic, B‐lymphocytic, and monocyte‐macrophage systems. Application of these methodologies to malignant lymphomas has established their nature as neoplasms of the immune system. Within the B‐lymphocytic system it is possible to identify subpopulations responsible for Burkitts tumor, follicular (nodular) lymphomas, lymphocytic lymphomas of intermediate differentiation and well differentiated lymphocytic lymphomas. The T‐lymphocytic system includes lymphoblastic lymphomas, mycosis fungoides, and Sezarys syndrome. Large cell lymphomas are diverse but the majority are tumors of transformed lymphocytes, usually of the B‐lymphocytic system. The precise nature of the neoplastic cells of Hodgkins disease, i.e., Reed‐Sternberg cells and their mononuclear counterparts, has not yet been established. Despite previous suggestions of a B‐lymphocytic or T‐lymphocytic origin, recent studies utilizing in vitro cultivation have strongly suggested derivation from the monocyte‐macrophage system.

Treatment With Carfilzomib-Lenalidomide-Dexamethasone With Lenalidomide Extension in Patients With Smoldering or Newly Diagnosed Multiple Myeloma.

IMPORTANCE Carfilzomib-lenalidomide-dexamethasone therapy yields deep responses in patients with newly diagnosed multiple myeloma (NDMM). It is important to gain an understanding of this combinations tolerability and impact on minimal residual disease (MRD) negativity because this end point has been associated with improved survival. OBJECTIVE To assess the safety and efficacy of carfilzomib-lenalidomide-dexamethasone therapy in NDMM and high-risk smoldering multiple myeloma (SMM). DESIGN, SETTING, AND PARTICIPANTS Clinical and correlative pilot study at the National Institutes of Health Clinical Center. Patients with NDMM or high-risk SMM were enrolled between July 11, 2011, and October 9, 2013. Median follow-up was 17.3 (NDMM) and 15.9 months (SMM). INTERVENTIONS Eight 28-day cycles were composed of carfilzomib 20/36 mg/m2 on days 1, 2, 8, 9, 15, and 16; lenalidomide 25 mg on days 1 through 21; and dexamethasone 20/10 mg (cycles 1-4/5-8) on days 1, 2, 8, 9, 15, 16, 22, and 23. Patients who achieved at least stable disease subsequently received 24 cycles of lenalidomide extended dosing. MAIN OUTCOMES AND MEASURES Primary end points were neuropathy of grade 3 or greater (NDMM) and at least very good partial response rates (SMM). Minimal residual disease was also assessed. RESULTS Of 45 patients with NDMM, none had neuropathy of grade 3 or greater. Of 12 patients with high-risk SMM, the most common of any-grade adverse events were lymphopenia (12 [100%]) and gastrointestinal disorders (11 [92%]). All patients with SMM achieved at least a very good partial response during the study period. Among the 28 patients with NDMM and the 12 with SMM achieving at least a near-complete response, MRD negativity was found in 28 of 28 (100% [95% CI, 88%-100%]), 11 of 12 (92% [95% CI, 62%-100%]) (multiparametric flow cytometry), 14 of 21 (67% [95% CI, 43%-85%]), and 9 of 12 (75% [95% CI, 43%-94%]) (next-generation sequencing), respectively. In patients with NDMM, 12-month progression-free survival for MRD-negative vs MRD-positive status by flow cytometry and next-generation sequencing was 100% vs 79% (95% CI, 47%-94%; P < .001) and 100% vs 95% (95% CI, 75%-99%; P = .02), respectively. CONCLUSIONS AND RELEVANCE Carfilzomib-lenalidomide-dexamethasone therapy is tolerable and demonstrates high rates of MRD negativity in NDMM, translating into longer progression-free survival in patients achieving MRD negativity. Carfilzomib-lenalidomide-dexamethasone therapy also demonstrates efficacy in high-risk SMM.

Terminal deoxynucleotidyl transferase activity in malignant lymphomas.

To determine the usefulness of terminal deoxynucleotidyl transferase enzyme activity as a biochemical marker in the study of lymphoma, we assayed 50 various malignant lymphomas as well as normal lymphoid tissue for this activity. Neoplastic cells from patients with Hodgkins disease, Burkitts tumor, Sézarys syndrome, chronic lymphocytic leukemia, leukemic reticuloendotheliosis and lymphocytic lymphomas (poorly differentiated and intermediate) were all without notable enzyme activity. Large-cell tumors of B-cell type were also negative. One of three large-cell tumors without B-cell or T-cell-surface specificity was positive (1.40 nmol per hour per milligram of DNA). Enzyme activity was consistently present only in lymphoblastic lymphomas (all six cases studied), with a mean activity of 7.80 nmol per hour per milligram of DNA. These six cases had heterogeneous surface immunomarkers. We conclude that terminal deoxynucleotidyl transferase is a biochemical marker that will be useful in the study of lymphoma.

Optimal number of reagents required to evaluate hematolymphoid neoplasias: Results of an international consensus meeting

At the ISAC 2000 Congress, the Clinical Cytometry Society organized a meeting of international experts to reach consensus on the minimum number of antibodies required for a full evaluation of hematologic and lymphoid neoplasias. A questionnaire was distributed prior to the meeting to numerous experts from US and European institutions and 13 responses were received. At the meeting, 25 individuals, including most of those who returned responses, participated in the discussions and voted on the issues presented. In chronic lymphoproliferative disorders (CLD), 9 antibodies (anti-CD5, CD19, kappa, lambda, CD3, CD20, CD23, CD10, and CD45) were deemed essential for initial evaluation by 75% of the participants. There was near unanimity that additional markers (selected from CD22, FMC7, CD11c, CD103, CD38, CD25, CD79b and heavy chains for B-cell disorders, and CD4, CD7, CD8, CD2, CD56, CD16, TCRa/b, and TCRg/d for T-cell disorders) would be needed to fully characterize CLD, although not every marker would be useful in all cases. Tissue lymphomas were believed to be similar to CLD, needing a minimum of 12--16 markers. However, for some cases, CD30, bcl-2, TdT, CD71, CD1a, and CD34 were cited as useful by the participants. Markers mentioned for plasma cell disorders included kappa, lambda, CD38, CD45, CD56, CD19, CD20, CD138, and heavy chains. Of 17 voting participants, 16 agreed that between 5 to 8 markers would be essential reagents for plasma cell disorders. For acute leukemia (AL), 10 markers (CD10, CD19, CD13, CD33, CD34, CD45, CD7, CD14, CD3, and HLADR) were considered essential by 75% of participants for initial characterization of the leukemia lineage. Most (>75%) agreed that at least one more B (CD20, CD22, CD79a, IgM), T (CD1a, CD2, CD4, CD5, CD8), myeloid (CD11b, CD15, CD64, CD117, myeloperoxidase), erythroid (CD36, CD71, glycophorin A), and megakaryocytic (CD41, CD61) reagents should be included in the essential panel. However, there was no agreement as to which was optimal. Thus, approximately 13--15 of those reagents would be considered essential in all cases of AL, whereas others (CD16, CD56, CDw65, TdT, and cytoplasmic CD3) were mentioned as useful in some cases. Almost all voting participants believed that the appropriate number of markers for complete characterization of AL would average 20--24. The majority of the responders (11 of 13) indicated that fewer reagents could be used in monitoring or staging patients with previously characterized disease, but not all ventured a specific number of reagents. From the above results, we conclude that the phenotypic analysis of hematologic and lymphoid neoplasia requires a rather extensive panel of reagents. Supplementary reagents might even be necessary if they prove to become relevant for diagnostic purposes. Reducing the number of antibodies could significantly compromise the diagnostic accuracy, appropriate monitoring, or therapy of these disorders.

Immunoblastic lymphadenopathy: Evolution into a malignant lymphoma with plasmacytoid features

In the patient described progressive lymphadenopathy, splenomegaly and interstitial pulmonary disease developed two months after the development of immunoblastic lymphadenopathy. Light microscopic examination of a lymph node biopsy specimen suggested a diagnosis of immunoblastic sarcoma. Evolution of this malignant lymphoma into a leukemic phase allowed detailed studies of the malignant cells by electron microscopy, cytochemical staining and immunologic technics. Evidence is presented that this is a case of malignant lymphoma with plasmacytoid and not lymphoid features. Review of the literature on immunoblastic sarcoma suggests that light microscopy and clinical setting are not sufficient to define a homogeneous clinicopathologic disease.

Structural and functional properties of the "hairy" cells of leukemic reticuloendotheliosis.

Structural and functional studies were performed on „hairy”︁ cells from 7 patients with leukemic reticuloendotheliosis („hairy cell leukemia”︁) (HCL). In all cases tartrate‐resistant acid phosphatase‐containing cells were demonstrated. The abnormal cells displayed complement receptors in 6 cases although there was variation in the number of abnormal cells expressing the receptor. Receptors for IgG were present in all 7 cases on a high number of abnormal cells. In 6 cases the „hairy”︁ cells showed surface immunoglobulins (SIg) when examined immediately after isolation. Procedures to eliminate in vivo bound protein substantially decreased the number of SIg‐bearing cells, indicating that most SIg represented cytophilic protein. In 2 cases, however, SIg restricted to a single light chain type remained on the abnormal cells, suggesting that in these 2 cases the SIg may have been an intrinsic cellular product. Attempts to demonstrate immunoglobulin synthesis were unsuccessful and there was no evidence that the „hairy”︁ cells contained cytoplasmic immunoglobulin. In vitro phagocytosis of latex particles by the abnormal cells was observed in all cases by transmission electron microscopy although the number of phagocytic „hairy”︁ cells varied widely from case to case. In 4 of 5 spleens with HCL, normal macrophages detected by the presence of nonspecific esterase were abundant and markedly enlarged. The electronic size distribution of HCL suspensions demonstrated a characteristic double‐peaked curve and modal volumes seldom seen in other chronic leukemias or lymphomas. Quantitative scanning electron microscopic analysis of HCL populations corroborated that the peculiar „hairy”︁ appearance of the abnormal cells was due to extensive surface ruffles which are not observed in normal or neoplastic lymphocytes. Our findings suggest that the „hairy”︁ cells are structurally and functionally unique elements, different than any other normal or abnormal cell of the lymphoreticular system known at present. Studies of cellular DNA quantitation and thymidine incorporation indicated that the growth rate of the „hairy”︁ cells is exceedingly low.

2006 Bethesda International Consensus recommendations on the flow cytometric immunophenotypic analysis of hematolymphoid neoplasia: Medical indications†

The clinical indications for diagnostic flow cytometry studies are an evolving consensus, as the knowledge of antigenic definition of hematolymphoid malignancies and the prognostic significance of antigen expression evolves. Additionally the standard of care is not routinely communicated to practicing clinicians and diagnostic services, especially as may relate to new technologies. Accordingly there is often uncertainty on the part of clinicians, payers of medical services, diagnostic physicians and scientists as to the appropriate use of diagnostic flow cytometry. In an attempt to communicate contemporary diagnostic utility of immunophenotypic flow cytometry in the diagnosis and follow‐up of patients with hematolymphoid malignancies, the Clinical Cytometry Society organized a two day meeting of international experts in this area to reach a consensus as to this diagnostic tool. This report summarizes the appropriate use of diagnostic flow cytometry as determined by unanimous approval of these experienced practitioners.

Cell volumes and dna distributions of normal and neoplastic human lymphoid cells

This study was designed to test the value of flow quantitative cytology in the diagnosis and classification of lymphoid neoplasias. Cells obtained from a variety of lymphoreticular malignancies as well as from non‐heoplastic lymphoid tissues and peripheral blood were assessed for their size distributions and their DNA contents using flow microfluorometry. The electronic modal volume (MV), the coefficient of variation of cell size (CV) and the percentage of cells containing DNA quantities between diploid and tetraploid values (S) were compared with the diagnoses determined by conventional morphological criteria. There was a general correlation between the size distribution of the cell populations as observed by optical methods and that measured electronically. Malignant populations obtained from peripheral blood could be differentiated from normal blood mononuclear cells. Normal thymic populations were distinctly different from all other populations due to their low MV. All „histiocytic”︁ (large cell) lymphomas showed either high MV or high CV. Most tumors composed morphologically of small cells displayed low MV. The cells of Burkitts tumor also showed relatively high MV and/or CV but to a lesser extent than the „histiocytic”︁ lymphomas. All hairy cell populations showed bimodal distributions and high MV. As expected, most mixed cell lymphomas showed high CV values. Marked variability of MV and/or CV were observed among lymphocytic lymphomas of intermediate differentiation and lymphoblastic lymphomas. A general correlation was also found between the percentage of cells in S in individual malignancies and their expected clinical behavior. Neoplasms known to be of low grade aggressiveness displayed low S values. Burkitts lymphomas showed in all cases the highest percentage of S and lymphoblastic and „histiocytic”︁ lymphomas displayed a wide range of S values. Cases of diffuse „histiocytic”︁ lymphoma with a previous history of nodular lymphoma showed lower S percentages than those appearing de novo. These observations suggest that the rapid, reproducible results provided by flow cytologic analysis may both aid in the diagnosis and classification of lymphoid tumors and also eventually contribute to predicting and monitoring therapeutic responses.

Malignant lymphoma obscured by concomitant extensive epithelioid granulomas: report of three cases with similar clinicopathologic features.

Three similar cases are described of an unusual combination of malignant lymphoma and extensive non‐necrotic granulomas. The three patients presented with prominent splenomegaly without peripheral lymphadenopathy. They had normal or moderately elevated lymphocyte counts, abnormal lymphoid cells in the peripheral blood and bone marrow, and abnormalities of serum immunoglobulins. The lymphoid tumor was difficult to recognize but it was best identified in abdominal lymph nodes, it was composed of small atypical lymphocytes proliferating in a vaguely nodular pattern. The presence of multiple epithelioid granulomas obscured the neoplastic proliferation in the spleens and misled or delayed the final interpretation of the malignant disease. Abdominal lymph nodes and liver also contained granulomas although to a lesser extent. Studies of the lymphocyte surface characteristics in one patient suggested that the neoplasm derived from a monoclonal proliferation of B cells. The relationship between the exuberant epithelioid granulomas and the underlying neoplastic lymphoid proliferation is not clear. Regardless of whether it represents a distinct clinicopathological entity, recognition of this remarkable association has important practical implications since the lesions may be erroneously interpreted by the pathologist.