Catherine S. Rangel

Immunobiologic factors predictive of clinical outcome in diffuse large-cell lymphoma.

The prognostic importance of immunobiologic factors in diffuse large-cell lymphoma (DLCL) is studied in 105 consecutive DLCL patients. Multivariate results using the Cox proportional hazards model clearly indicate that the Ki-67 index (P = .002), a marker of cell proliferation activity, and the presence or absence of human leukocyte antigen-DR (HLA-DR) (P = .007) are strong predictors of survival even in the presence of established clinical factors of stage (P = .015) and symptoms (P = .050). Using these four variables, prognostic groups were formed identifying patient groups with varying degrees of risk. The group of patients with three or four risk factors present at the time of diagnosis had a median survival of 4 months compared with a median survival of 59 months for the group with no risk factors. Similarly, prognostic groups for disease-free survival (DFS) were constructed based on the proportional hazards model that involved B versus T phenotype (P = .035) and HLA-DR (P = .054). Median DFS for the patient group with one or two risk factors present was 11 months compared with 43 months with no risk factors present. This study suggests immunobiologic parameters are important predictors of clinical outcome in DLCL patients and are of value in identifying subgroups of patients who have not responded to currently available therapy. The practical significance of this study is to identify parameters that may suggest specific changes in therapy of patient subgroups.

Signet-ring cell lymphoma of T-cell origin. An immunocytochemical and ultrastructural study relating giant vacuole formation to cytoplasmic sequestration of surface membrane.

In contrast to previous accounts of signet-ring lymphoma as a B-cell neoplasm, we report a case of signet-ring, large-cell lymphoma of T-cell lineage. Immunologic and ultrastructural studies were performed on a subcutaneous mass noted initially, as well as on an enlarged lymph node that developed later, in a 69-year-old man. Immunologic assessment indicated strong expression of T-helper antigen (Leu 3a + b), universal T-antigens (Leu 1, 5), and Ia. There was an absence of T-suppressor/cytotoxic antigen (Leu 2a), universal T-antigens (Leu 4, 9), and immunoglobulin light and heavy chains. Collectively, these findings indicate a mature T-cell lymphoma of T-helper type in an activated (Ia+) state. In contrast to previous reports of T-cell and Ia occurring solely as surface antigens, we demonstrated pools of cytoplasmic Leu 1, 3, 5 and Ia that displaced the nucleus. The ultrastructure of the giant cytoplasmic vacuoles was identical to the microvesicle-containing vacuoles reported in signet-ring cell lymphomas of B-cell lineage. In our case of T-cell lineage, we found substantial evidence of endocytosis by the neoplastic cells and numerous giant multivesicular bodies. The pools of cytoplasmic T and Ia antigens may result from abnormal internalization of surface T-antigens or the sequestration of T-antigen-containing Golgi-derived vesicles. Our combined immunologic and ultrastructural findings suggest that aberrant membrane recycling may be the common denominator of signet-ring formation in both B- and T-cell signet-ring lymphomas.

A comprehensive immunotopographic map of human thymus

We have achieved a comprehensive immunotopographic mapping of human thymus by using a large battery of monoclonal antibodies and the methodological refinement of comparative serial tissue section immunohistochemistry, allowing analysis of multiple phenotypes in the same tissue site. Previous immunohistochemical studies of thymus have concentrated on the majority T-cell and epithelial cell populations. Besides demonstrating the complexity of T-cell antigenic expression (e.g., simultaneous cortical expression of Leu 2, Leu 3, CALLA, Tdt, and Leu 6), we delineate surprisingly complex B-cell zones (e.g., septal B-follicles with DRC+C3d+ dendritic cells and zonal maturation of B-cells). Whereas septal B-follicles were found in 25% of cases, medullary B-cells were universally present as a substantial minority component. This expanded immunotopographic knowledge of the complex T-, B-, epithelial, and reticulum cell neighborhoods suggests that the thymus is an organ capable of a broad repertoire of immunological responses, not limited to T-cell development.

Cutaneous myiasis. Immunohistologic and ultrastructural morphometric features of a human botfly lesion.

This study documents the immunohistologic and ultrastructural morphometric features of a case of cutaneous myiasis due to Dermatobia hominis. The mixed host inflammatory response surrounding the larvae included lymphoblasts, eosinophils, activated fibroblasts, mature histiocytes, mast cells, plasma cells, and Langerhans cells, indicating a complex interactive immunologic response to the botfly parasite. Immunotyping revealed that the dominant dermal cells were activated (Ia+) T-helper cells. Although the strikingly elevated T-helper/T-suppressor cell ratio might suggest a monoclonal infiltrate, a mixture of Leu 8+ and Leu 8- T-cells indicates both immunoregulatory subsets of T-helper cells as found in a reactive process. Furthermore, our ultrastructural histogram found the lymphoid nuclear shapes were oval with few nuclear invaginations as found in inflammatory infiltrates. As indicated by electron microscopy, there were abundant activated fibroblasts elaborating collagen which may relate to larval containment.

Diffuse small cleaved-cell lymphoma: a heterogeneous disease with distinct immunobiologic subsets.

PURPOSE AND METHODS Diffuse small cleaved-cell lymphoma (DSCL) is a relatively uncommon non-hodgkins lymphoma (NHL) in the United States and has not been the subject of recent in-depth study of factors predictive of outcome. It is unique among the NHL of intermediate grade because there is no evidence of a curable subset of patients. To investigate whether any laboratory data might predict outcome, we studied 33 cases collected during a 12-year period and correlated morphology, immunohistochemistry, and serum lactate dehydrogenase (LDH) with clinical data and outcome. RESULTS We found that proliferative rate (Ki-67), cell lineage (T v B cell), and serum LDH were associated with significant differences in survival. A Ki-67 value greater than or equal to 20% was associated with a median survival of 20 months compared with 80 months for lower values (P = .0002); patients with tumors of T-cell lineage had a median survival of 20 months compared with 40 months for those with B-cell neoplasms (P = .0143); and a serum LDH greater than 225 IU/L was associated with a median survival of 8 months compared with 40 months for lower LDH levels (P = .0004). Blastoid morphology was also linked to a trend toward poor outcome (P = .08). Neither a history of low-grade lymphoma nor the presence of residual immunologically detectable follicles influenced outcome (P = .93 and .97, respectively). CONCLUSION We conclude that high Ki-67, high LDH, and T-cell lineage each identify DSCL patients with poor outcome.

Immunotopographic assessment of lymphoid and plasma cell malignancies in the bone marrow.

To determine the utility of tissue section immunochemistry in the evaluation of bone marrow involved by lymphoid and plasma cell malignancies, snap-frozen, undecalcified bone marrow core and aspirate samples from 23 patients with these disorders were studied with a battery of monoclonal antibodies. With techniques that preserve architecture, difficult diagnostic cases characterized by core but not aspirate involvement, or the reverse, were resolved. By means of an extensive battery of monoclonal antibodies applied to serial sections, complex tumor cell phenotypes were established in all 23 cases. In addition to the identification of straightforward monoclonal surface immunoglobulin expression in small cleaved cell lymphomas (four cases), the battery approach added immunologic certainty in malignancies with unusual or difficult phenotypes: peripheral T-cell lymphomas with idiosyncratic antigen expression, and chronic lymphocytic leukemias and small cell lymphomas with faint surface immunoglobulin expression (four cases). For the chronic lymphocytic leukemias and the small cell lymphomas, the combined IgD+, B2+, B1+, Ia+, Leu-1+ phenotype taken as a whole had greater utility than any isolated marker. The acute lymphocytic leukemias and the myelomas studied demonstrate the wide range of B-cell antigens that must be detected to account for the variety of B-cell neoplasms encountered. Additionally, the previously undescribed phenotypic subset of CALLA+ myelomas, which is of prognostic relevance, was identified. Marrow frozen section immunotyping is a major asset in the evaluation of patients with lymphoma, leukemia, and myeloma when special care is accorded to tissue handling and to treatment of endogenous peroxidase/pseudoperoxidase and interstitial immunoglobulin.

A Multidisciplinary Approach to the Diagnosis of Cutaneous T-Cell Lymphomas

The cutaneous T-cell lymphomas (CTCLs) comprise a spectrum of non-Hodgkin lymphomas with a predilection for the skin. This heterogeneous group of CTCLs include the prototypic CTCL mycosis fungoides (MF) and the recently described Ki-1+ lymphomas. MF is notoriously difficult to diagnose in its early stages. The histologic appearance of early MF is indistinguishable from that of chronic dermatitis. The limitations of light microscopy in the diagnosis of the CTCLs have led to the development of other diagnostic laboratory techniques. The best approach to the diagnosis of the CTCLs is a multidisciplinary one and should include ultrastructural morphometry, immunophenotyping, immunogenotyping, and histologic evaluation whenever possible. It is the purpose of this overview to point out the strengths and weaknesses of each of these techniques and, together with clinical input, to provide a comprehensive and rational approach to patient care.

The Tissue Microarray: Helpful Hints!

Abstract The tissue microarray (1) has revolutionized how major research projects involving patient or veterinary studies can be carried out. Hundreds of samples can be studied on one slide at a time. The benefits of this type of study save on tech time, cost of supplies for both reagents and antibodies, slides, and hands-on time or machine time, depending on the staining method used. The purpose of this article is to give some practical hints that may benefit those trying to do microarray sectioning and special staining techniques. (The J Histotechnol 25:91, 2002) Submitted March 31, 2002; accepted April 5, 2002

Immunologic approaches to the classification of non-Hodgkin’s lymphomas

This chapter employs the working formulation (WF) of the non-Hodgkin’s lymphomas as a histologic base, because its ten morphologic categorizations are well defined and of established clinical utility, identifying prognostic gradations relevant to therapy [1]. Using this firm histologic base, the immunologic characteristics within each category are emphasized. As this chapter repeatedly demonstrates, many immunologic subtypes exist within certain WF categories, and these cannot always be predicted by morphologic classification [2]. Figure 1A details the WF categorizations relevant to the previously widely used Rappaport classification [3]. Figure 1B details some closely related entities to be discussed. Some of these represent lymphoma-related diseases, others represent newer categorizations derived from immunologic studies (e.g., peripheral T-cell lymphoma).

Immunohistochemistry in leukemias and lymphomas.

The characterization of the antigenic and immunologic properties of lymphoid and hematologic neoplasms has dramatically increased our understanding of the biology of these diseases and at the same time greatly enhanced our diagnostic abilities. Immunophenotyping has helped delineate specific lineage aberrancies indicative of malignant transformation, such as monoclonality, in the form of light- and/or heavy-chain immunoglobulin restriction, or loss of pan-B or pan-T cell antigens, or aberrant crosslineage coexpression of antigens. Unique immunophenotypic profiles have now been described for most forms of lymphoma and leukemia. Classic Hodgkins disease, for example, has the singular combination of CD15 and CD30 positivity, in the absence of CD45 (see Fig. 1 ). Additional examples are mantle cell lymphoma with its unique nuclear expression of cyclin D1, and hairy cell leukemia, characterized by coexpression of CD22 and CD1 1c, a monocytoid marker. Beyond its diagnostic utility, immunohistochemistry (IHC) may have prognostic significance reflecting the biologic behavior of these diseases; a case in point is CD 10 in large B-cell lymphomas, whose absence conveys a worse prognosis. Fig. 1. Classic Hodgkins disease phenotype. Reed-Sternberg cell (upper left) coexpressing CD 15 (upper right) and CD30 (lower right), in the absence of CD45 (lower left).