Monomorphic lymphomas arising in patients with Hodgkin's disease. Correlation of morphologic, immunophenotypic, and molecular genetic findings in 12 cases

Patients with Hodgkin's Disease (HD) occasionally develop monomorphic lymphomas in which mononuclear cells, usually large in size, grow in sheets, and in which there are few reacting cells or classic Reed-Sternberg (RS) cells. Twelve patients of this type were reviewed to determine the nature of the monomorphic growth. Paraffin-embedded tissue sections from the original diagnostic HD and the monomorphic growths were stained for Leu-M1 (CD15), leukocyte common antigen (LCA, CD45), pan B-cell markers LN1, LN2, and L26, and pan T-cell marker UCHL1 (CD45R) reactive in paraffin-embedded tissues. Cases were included only if the original diagnostic material had the classic histopathologic features of HD, if there was a separate monomorphic growth (in place or time), and if sufficient materials from both phases were available for study. Original diagnoses of HD included nodular sclerosing (NS; 8 cases); lymphocyte predominant (LP; 2 cases); mixed cellularity (MC; 1 case); and lymphocyte depleted (LD: 1 case) types. RS cells in the eight cases of NS HD and one case of MC HD were generally Leu-M1 and LN2 positive, and L26, LN1, UCHL1, and LCA negative. RS cells in one case of NS HD were LCA positive in addition to Leu-M1, LN1, and LN2. Two cases of NS HD showed L26 positive RS cells. Conversely, RS cells and lymphocytic-histiocytic (L and H) variants in the cases of LP HD were Leu-M1 and LN2 negative, and LCA and LN1 positive. The one case of LD HD possessed RS cells that were negative for Leu-M1, but positive for LCA, L26, LN1, and LN2. In seven cases (4 NS, 2 LP, 1 LD) the monomorphic growths possessed a B-cell phenotype (LCA, L26, and LN1 positive; Leu-M1 and UCHL1 negative). In the remaining cases (4 NS, 1 MC), the monomorphic growths were Leu-M1 positive, and displayed phenotypes similar to the RS cells of the original NS HD. Southern blot analysis was performed on the monomorphic components of five cases and showed some form of immunoglobulin gene rearrangement in each (4 cases: rearranged heavy chain-joining region gene; 1 case: rearranged Mu chain-constant region gene). Two of these cases expressed L26 and LN1 in the monomorphic phases. Despite apparent immunoglobulin gene rearrangement, one case expressed T-cell antigens Leu-4 (CD3) and Leu-1 (CD5), in addition to Leu-M1 (CD15).(ABSTRACT TRUNCATED AT 400 WORDS)     

Immunophenotypic analysis of acute lymphoblastic leukemia using routinely processed bone marrow specimens

Monoclonal antibodies have been recently developed that react with antigens expressed on T and B lymphocytes in routinely processed, paraffin-embedded lymphoid tissues. In this study, we assessed bone marrow clot and/or core biopsy sections of 19 cases of acute lymphoblastic leukemia (ALL) using routinely decalcified, B5- or formalin-fixed, paraffin-embedded sections and a panel of monoclonal antibodies, including LN1, LN2, L26, Leu-22, UCHL-1, and LCA. Each case had been previously phenotyped using freshly obtained aspirate material and a standard immunophenotypic protocol. Our results demonstrate the utility of the LN2 antibody in differentiating between precursor B-cell (pre-B) and precursor T-cell ALL. The LN2 antibody stained 11 of 12 cases of pre-B ALL and did not react with any of the seven T-cell ALLs. The other antibodies tested were less helpful. The Leu-22 antibody stained both pre-B and T-cell ALLs, while the results with UCHL-1 revealed peculiar nuclear staining of pre-B and T-cell ALLs; this we attributed to processing artifact. The L26 antibody reacted with only one case of pre-B ALL (also CD20 antigen positive), while the LN1 antibody did not react with any pre-B ALLs. Neither L26 nor LN1 stained any cases of T-cell ALL. The LCA antibody stained in only four (21%) of 19 cases, two pre-B and two T-cell ALLs. The results also suggest that this panel of antibodies may be useful in differentiating ALL from mature B-cell and T-cell lymphomas involving the bone marrow.     

Leu-22 (L60). A more sensitive marker than UCHL1 for peripheral T-cell lymphomas, particularly large-cell types

Paraffin-embedded sections of 77 peripheral T-cell lymphomas (PTCLs) were stained with several monoclonal antibodies, including the preferential T-cell markers Leu-22 (L60[CD43]) and UCHL1 (CD45RO). The staining characteristics of L60 and UCHL1 were compared to determine the value of each in the immunophenotypic analysis of PTCLs. Lineage specificity was evaluated among 39 B-cell lymphomas and 33 cases of Hodgkin's disease (HD). L60 and/or UCHL1 stained 95% of PTCLs, whereas L60 and UCHL1 alone stained 90% and 69% of cases, respectively. L60 demonstrated significantly greater numbers of immunopositive tumor cells than UCHL1 in 37% of the PTCL cases, principally because of enhanced marking of large, neoplastic cells. UCHL1 was a better marker in only 10% of the PTCL cases. L60 stained 33% of B-cell lymphomas, usually small lymphocytic or lymphoplasmacytic types. UCHL1 stained only 8% of B-cell lymphomas, all large-cell types. L60 and UCHL1 stained Reed-Sternberg cells and variants in three cases of nodular sclerosing HD. These results suggest that both L60 and UCHL1 are useful markers of PTCLs in routinely processed tissue. L60 is a more sensitive marker of large neoplastic T-cells than UCHL1 but is less lineage-specific. These antibodies are most effective when used as part of a panel of monoclonal antibodies.     

Expression of T-cell antigens on Reed-Sternberg cells in a subset of patients with nodular sclerosing and mixed cellularity Hodgkin's disease

Expression of T-cell antigens by Reed-Sternberg (RS) cells has not been detected in most studies of Hodgkin's disease (HD). The authors employed an improved method of fixation (paraformaldehyde-lysine-periodate), which sharply defined cell borders and revealed T-cell antigens on RS cells in 8 of 30 (27%) cases of HD. Antigen-specific staining was confirmed by immunoelectron microscopy. RS cells expressed T11 (8/8 cases), Leu-3 or T4 (4/8 cases), Leu-4 or T3 (3/8 cases), but not other T-cell specific antigens (Leu-1, T8, T6, 3A1). RS cells were negative for leukocyte common antigen (LCA/T200), in contrast to positive LCA/T200 staining of RS-like cells in T-cell lymphomas. RS cells in all HD cases were positive for Ki-1 and/or Leu-M1 antigens. The percentage of RS cells expressing T-cell antigens was less than 20% (2 cases), 20-50% (3 cases), or greater than 50% (3 cases). This percentage and the specific T-cell antigens expressed varied in tissues from different sites in each of 2 cases. Expression of T-cell antigens by RS cells was found in nodular sclerosis (6 of 20 cases) and mixed cellularity (2 of 5 cases) but not in lymphocyte predominance (2 cases), lymphocyte depletion (1 case), or unclassified types (2 cases). Two cases of nodular sclerosis contained areas of necrosis surrounded by sheets of lacunar cells (syncytial variant of NSHD). Two other cases were associated with cutaneous lymphoma. One of these cases was mixed cellularity HD, which appeared to be confined to the skin. In a second case, tumor cells of similar phenotype (T4+, Ki-1+) were found in skin and lymph nodes of a patient with coexistent mycosis fungoides and HD. These results are consistent with an origin of RS cells from T cells in some cases of nodular sclerosing and mixed cellularity HD. They also suggest that the same cell type, an activated helper T-cell, is involved in the pathogenesis of both skin lesions and lymphadenopathy of some patients with coexistent mycosis fungoides and HD.     

Methods in pathology. Identification of T-cell lymphomas in paraffin-embedded tissues using polyclonal anti-CD3 antibody: comparison with frozen section immunophenotyping and genotypic analysis.

While L26 (CD20) is now well established as a B-cell marker of high specificity for use in paraffin-embedded tissues, paraffin-reactive T-cell antibodies (UCHL1, MT1, Leu-22, DF-T1, and MT2) have not shown comparable lineage specificity. A new commercially available polyclonal antibody directed against a synthetic peptide sequence of the CD3 (T-cell) antigen has recently become available for use on paraffin sections. In order to evaluate the utility of this antibody, we studied CD3 expression in conjunction with L26 and leukocyte common antigen (LCA) in 15 T-cell and 20 B-cell non-Hodgkin's lymphomas (NHL), all genotypically confirmed by DNA hybridization and immunophenotyped by immunoperoxidase studies in frozen tissue. Ten of 15 T-cell NHLs (67%) showed unequivocal immunolabeling of neoplastic cells with anti-CD3 in paraffin-embedded tissue. Of the five negative cases, three were lymphoblastic lymphomas, and two were peripheral (postthymic) lymphomas (one anaplastic large cell, Ki-1 positive and one large cell, immunoblastic). CD3 expression was identical in paraffin and cryostat sections (100% concordance). Twenty of 20 B-cell NHLs were positive with L26 and LCA but were negative with anti-CD3. Other neoplasms examined, including three granulocytic sarcomas and 45 nonhematopoietic tumors, were similarly negative with anti-CD3. We conclude that polyclonal anti-CD3 is a sensitive and highly specific T-cell marker in paraffin-embedded tissue and, when used in conjunction with LCA and L26, that it can determine cell lineage in the majority of non-Hodgkin's lymphomas.     

Immunohistological analysis of the immunoreactivity of normal lymphoid cells and lymphomas with the monoclonal antibody OPD4

OPD4 is a recently described monoclonal antibody that recognizes a fixation-resistant 200 kD antigen restricted to a subset of T cells. Immunolabelling with OPD4 in paraffin sections of normal lymphoid tissues and cases of malignant lymphoma was compared with that of other antibodies in common use, including the T-cell restricted antibodies MT1 and UCHL1 and the B-cell restricted antibodies MB1, F8-11-13, and L26. OPD4 showed similar immunoreactivity to UCHL1 in normal tissues. OPD4 did not stain Reed-Sternberg cells in Hodgkin's disease. In non-Hodgkin's lymphomas, OPD4, like UCHL1, reacted with only 2/22 B-cell lymphomas. OPD4 was, however, less useful as a marker of T-cell lymphomas, staining only 11/32 cases, while UCHL1 stained 22/32 cases. We conclude that OPD4 is not a useful antibody for the routine diagnosis of T-cell lymphoma.     

Immunoarchitecture of normal human bone marrow: a study of frozen and fixed tissue sections.

To provide baseline information on the immunoarchitecture of normal bone marrow, we studied cryostat-cut, frozen, and paraffin-embedded, fixed tissue sections prepared from 21 core biopsies of normal bone marrow obtained during bone marrow harvests for transplantation. A large panel of antibodies was applied that included, for frozen tissue, Leu-6 (CD1), T11 (CD2), Leu-3a (CD4), Leu-1 (CD5), Leu-2a (CD8), J5 (CD10), My7 (CD13), Leu-11 (CD16), B4 (CD19), B1 (CD20), B2 (CD21), Tac (CD25), My9 (CD33), T200 (CD45), NKH-1 (CD56), kappa and lambda chains, beta F1, Ki-67, HLA-DR, TQ1, and keratin, and for fixed tissue, leukocyte common antigen (CD45), L26 (CD20), LN1 (CDw75), LN2 (CD74), LN3, LN4, LN5, MB1 (CD45R), MB2, MT1 (CD43), MT2 (CD45R), UCHL1 (CD45R0), BM1, Ki-1 (CD30), Leu-M1 (CD15), lysozyme, KP1 (CD68), actin, S100, neuron-specific enolase, vimentin, and keratin. On fresh-frozen sections CD19 and CD2 were the most reliable and sensitive markers for B and T cells, staining 5% and 9% of marrow cells, respectively. Immunoglobulins generally showed heavy background staining, which frequently precluded an accurate assessment. The CD4 to CD8 ratio in the bone marrow was reversed from that of peripheral blood. On fixed tissues, leukocyte common antigen was found in 14% of the marrow cells, corresponding roughly to the lymphocyte population. L26, a pan-B-cell marker, stained 3% of the marrow cells. Among the other B-cell markers, LN1 and MB2 stained a large number of cells (40% to 70%), indicating reactivity with cells of the myeloid or erythroid series in addition to lymphocytes. Among the T-cell markers, UCHL1 and MT1 stained 66% and 50% of the cells, respectively, which could be explained by their cross-reactivity with myeloid cells. Nonspecific myelomonocytic markers (Leu-M1, KP1, and lysozyme) also showed reactivity in a high percentage of cells. No particular architectural distribution patterns of B or T lymphocytes were noted in either frozen or fixed bone marrow specimens. The results of this study provide normal baseline data for the immunohistologic application of hematopoietic and lymphoid markers on frozen or fixed bone marrow biopsy specimens.     

Use of monoclonal antibodies for the typing of malignant lymphomas in routinely processed biopsy samples

Eight antibodies (UCHL1 (CD45RO), MT1 (CD43), MT2 (CD45R), 4KB5 (CD45R), MB1 (CD45R), MB2, L26 (CD20) and LN1 (CDw75)) have been examined for reactivity with routine specimens of normal and hyperplastic lymphoid organs (n = 6), non-Hodgkin's lymphomas (n = 62), Hodgkin's disease (n = 27) and non-lymphoid malignancies (n = 9). In normal and hyperplastic lymphoid organs, UCHL1 and MT1 stained predominantly T cells; 4KB5, MB1, MB2, L26 and LN1 stained predominantly B cells; and MT2 reacted with a subset of B and T cells. The lineage of the neoplastic cells was correctly identified in 24 of 28 (86%) peripheral T-cell lymphomas; and in 31 of 35 (88%) B-cell malignancies. In two cases of lymphocyte-predominant Hodgkin's disease, the Hodgkin's and Reed-Sternberg (H&RS) cells were 4KB5+, L26+ and/or LN1+. The H&Rs cells in nodular sclerosis and mixed cellularity Hodgkin's disease were positive with 4KB5 in 17 of 25 cases. Antibodies UCHL1, MT1, MB1, MB2, L26 and LN1 also labelled some H&RS cells, but in a much smaller proportion of the cases. In three of nine non-lymphoid neoplasms, UCHL1 and MB2 showed a staining of the neoplastic cells, but the staining was cytoplasmic rather than membrane-associated. The remaining antibodies were unreactive with the non-lymphoid malignancies. It is concluded that many non-Hodgkin's lymphomas can be typed in routine specimens, and that antibodies UCHL1, MT1, L26 and LN1 are especially useful in this respect. The antibodies do not provide a means of distinguishing between non-Hodgkin's lymphomas and Hodgkin's disease.     

Stereotactic biopsy diagnosis of primary non-Hodgkin's lymphoma of the central nervous system. A histological and immunohistochemical study

We report 29 cases of primary non-Hodgkin lymphomas (NHL) of the Central Nervous System (CNS), 26 of which were diagnosed by stereotactic biopsy and 3 by autopsy. In seven cases the patients were affected by AIDS. Histological examination of this series revealed 15 cases of immunoblastic lymphoma, 12 cases of centroblastic lymphoma, 1 case of lymphoplasmacytic immunocytoma and 1 case of unclassified high grade lymphoma. By immunohistochemistry the B-cell origin of lymphoma cells was demonstrated in 28/29 cases. Eight cases were assigned to the B-cell lineage by demonstration of monotypic surface or cytoplasmic immunoglobulin or of the B-cell phenotype CD22+, CD2-, CD3-, CD5-. In twenty cases the B-cell nature of lymphoma was identified by positivity with two or more anti-B monoclonal antibodies (LN1LN2MB2) and negativity by the anti-T monoclonal antibody UCHL1. The histologically unclassified case was a peripheral T-NHL (CD1-, CD2+, CD3-, CD5+, CD22-). We conclude that histological and immunohistological evaluation of stereotactic biopsy specimens provides sufficient information for diagnosis and phenotypic characterization of primary NHL of the CNS. These lymphomas exhibit important predominance of high-grade malignancy histological types and are nearly always B-cell derived. In addition, we provide further evidence that the panel of monoclonal antibodies LN1, LN2, MB2, and UCHL1 is useful for immunophenotypic characterization of brain lymphomas when only paraffin embedded stereotactic biopsy tissue is available.     

Clinicopathological and cell immunophenotypic analysis of 54 cases of malignant nasopharyngeal/nasal lymphoma]

54 cases of nasopharyngeal/nasal non-Hodgkin's malignant lymphoma (NP/N-ML), including 41 cases of NP-ML and 13 cases of N-ML, were analyzed histologically and immunohistochemically and all of these materials were prepared in paraffin sections. They were all of diffuse type but one, of follicular type. Large cell type lymphomas were more commonly seen in this series (53.1%), and immunoblastic type with cell pleomorphism was more common in N-ML. A panel of monoclonal antibodies composed of LCA, L26, LN2, UCHL1, Leu22, Mac387 and Leu7 was used in this study. There were 27 cases exhibiting T-cell phenotype and 21 cases showing B-cell phenotype. No histiocytic type was found. The ratio of T, B cell lymphomas was different in NP-ML(T: B = 17: 18) and N-ML (T: B = 10: 3) groups, and the predominance of T-cell N-ML was obvious. Immunostaining with cytokeratin, LCA, L26, UCHL1 is of great help in differential diagnosis and immunophenotyping.     

Value of monoclonal antibodies in the diagnosis of Hodgkin's disease in paraffin sections]

A comprehensive panel of monoclonal antibodies that mark R-S/H cell, T- and B-cell, monocyte/histocyte was tested in paraffin sections of 107 cases of Hodgkin's disease (HD) including 21 cases of lymphocyte predominance (LP) and 86 cases of Non-LP HD. Thirty cases each of peripheral T-cell lymphoma and B-cell lymphoma were also tested for comparison. R-S/H cells were not stained with T-cell marker (UCHL-1) or monocyte/histocyte marker (Mac387) in all of these cases of HD. The results showed presence of certain difference in the phenotype of LP from non-LP. The H+L type of R-S/H cells of LP often reacted with B-cell markers including L26, LN2, LN1 and MB2 (93.3%-100%), LCA (83.3%) and EMA (92.3%), but rarely with LeuM1,T mü 9, or BerH2. On the contrary, most of the R-S/H cells of non-LP reacted with LeuM1 (80%), T mu 9(84%), BerH2(65%) but not with B-cell markers, LCA or EMA. Our study suggests a B-cell (probably the follicular center cell) derivation for L+H type of R-S/H cells in LP. The fact that 1 case of LP in this group transformed to a large cell B-cell lymphoma also supports this consideration. PNA is a sensitive marker of R-S/H cells but is not a specific one, since PNA stains 43.3% of the peripheral T-cell lymphoma and 20% of the B-cell lymphomas. Our findings indicate that using a panel of antibodies which mark R-S/H cells, T- and B-cells in paraffin sections will be helpful in the diagnosis and subtyping of Hodgkin's disease.     

Immunohistochemical evaluation of neoplasms in bone marrow biopsies using monoclonal antibodies reactive in paraffin-embedded tissue

A panel of commercially available monoclonal antibodies (MoAbs) including LN1, LN2, MB2, L26, Leu M1, UCHL1, MT1 and L60 was used to evaluate a diverse group of neoplastic processes in 256 Zenker's-fixed, decalcified, paraffin-embedded bone marrow biopsies using the ABC immunoperoxidase technique. LN2 and MB2 were useful in delineating the extent of B-cell lymphoproliferative processes and in identifying interstitial patterns of involvement. The combined application of LN2, MB2 and UCHL1 had utility in differentiating B-cell from T-cell lymphoproliferative processes; in no instance was reactivity with LN2 observed in T-cell processes. The combined application of these three MoAbs was also used in differentiating benign reactive lymphoid aggregates from focal malignant B-cell proliferations. LN2 exhibited positivity with the Reed-Sternberg cells (RSC) of Hodgkin's Disease (HD) and significantly aided in the identification of these cells. Staining of RSC with Leu M1 was inconsistent and was observed in only 50% of cases of HD. Use of the entire panel of MoAbs together with more recently available reagents such as Cathepsin G, MAC 387 and neutrophil elastase was essential in optimally evaluating a particular lesion; none of these MoAbs used singly reliably differentiated myeloid from lymphoid, hematopoietic from metastatic, or reactive from malignant processes.     

Analysis of epithelial and lymphoid phenotypic markers in relation to growth pattern of colorectal adenomas.

The relationship of villous to tubular adenomas is poorly understood and often difficult to characterize morphologically. A villous growth pattern in colorectal adenomas has been associated with a higher frequency of high-grade dysplasia. We compared phenotypic markers using immunoperoxidase techniques in paired samples of villous (75% to 100% villous) and pure tubular adenomas matched for size and degree of dysplasia, which were selected by review of 1,000 polyps from our files. The following monoclonal antibodies were used: CAM 5.2 and AE1/AE3 to cytokeratins; B18, D14, B7.1, and B7.8 to four distinct carcinoembryonic antigen epitopes; Leu-M1 and LN3 to HLA-DR antigen; LN2 to invariant chain class II major histocompatibility complex; LN1 and MB2 to B-cell markers; UCHL1 and MT1 to T-cell markers; Leu-7 to natural killer cells; Mac 387 to macrophages; S-100 to Langerhans-type cells; and a polyclonal antibody to secretory component. LN3 reactivity correlated with villous morphology and secretory component correlated with tubular morphology. Combined HLA-DR and secretory component expression discriminated between tubular and villous growth patterns in 12 of 15 pairs of adenomas (P less than .001). LN2 was expressed more frequently than LN3, but did not correlate with growth pattern. Neuroendocrine cells (Leu-7) were more frequent in tubular adenomas. Carcinoembryonic antigen epitopes did not relate to growth pattern. We did not confirm previously reported differences in cytokeratin expression. We concluded that among the markers tested, HLA-DR expression, which may have an immunologic basis, is most characteristic of colorectal adenomas that exhibit a villous growth pattern.     

Molecule detected in formalin fixed tissue by antibodies MT1, DF-T1, and L60 (Leu-22) corresponds to CD43 antigen.

Three monoclonal antibodies MT1, L60 (Leu-22), and DF-T1, were reported independently as recognising human T cells in routinely processed, paraffin wax embedded tissue. The present study was performed to compare these three reagents in terms of their immunocytochemical reactions and target molecule(s). On Western blotting of white cell extracts the three antibodies reacted with antigens of the same molecular weight (range 110-160 kilodaltons). Furthermore, their immunocytochemical reactivity with normal human cells, as analysed by two-colour flow cytometry, was essentially identical (labelling of monocytes, most T lymphocytes, and weak reactions with some B cells), and the antibodies gave closely similar reactions on 54 white cell derived neoplasms. To identify the target antigen for these three reagents, antibodies from the Third International Workshop on Leucocyte Antigens were reviewed and it was shown that the Western blotting and immunocytochemical reactions of MT1, L60 (Leu-22), and DF-T1 were identical with those of the reagents which defined the CD43 antigen (also known as leucosialin or sialophorin). Furthermore, all these antibodies reacted with cells transfected with a cDNA clone encoding CD43. It is concluded that antibodies MT1, L60 (Leu-22), and DF-T1 all recognise the heavily glycosylated myeloid/lymphoid associated CD43 antigen.     

Human dendritic cells and macrophages. In situ immunophenotypic definition of subsets that exhibit specific morphologic and microenvironmental characteristics.

Using a panel of monoclonal antibodies and antisera in situ, the authors have defined subsets of human dendritic cells and macrophages that exhibit specific morphologic and microenvironmental characteristics. All subsets contained cells that reacted with antibodies directed against HLA-A,B,C, HLA-Dr, leukocyte common, Leu-M3, and Leu-3(T4) antigens. R4/23 and anti-S100 defined three major subsets. R4/23+, S100- cells constituted the B-cell-related follicular dendritic cells, which were identified only within the germinal center/mantle microenvironment of lymphoid follicles. R4/23-, S100+ cells constituted the T-cell-related dendritic cell subset. Anti-Leu-6(T6) further subdivided this group into Leu-6(T6)- interdigitating cells within the T-cell microenvironments of lymphoid organs and Leu-6(T6)+ Langerhans cells found predominantly in epithelial microenvironments, especially the skin. R4/23-, S100- cells constituted the nondendritic tissue macrophage subset which was widely distributed, primarily outside of dendritic-cell microenvironments. These data indicate that although dendritic cells and macrophages share several common antigenic features, morphologically and microenvironmentally distinct subsets express distinct immunologic phenotypes. Such data may provide insight into the ontogeny and function of these subsets and constitute a basis for the comparison of normal dendritic cells and macrophages to various histiocytic proliferative disorders.     

Antigenic phenotypes of hairy cell leukemia and monocytoid B-cell lymphoma: an immunohistochemical evaluation of 66 cases.

Using a large panel of antibodies on multi-tumor block sections of routinely processed, paraffin-embedded fixed tissue, we compared the antigenic phenotype of 42 clinically, morphologically, and immunologically well-characterized cases of hairy cell leukemia (HCL) with 24 cases of monocytoid B-cell lymphoma (MBCL) selected from the Monocytoid B-Cell Lymphoma Registry at the City of Hope National Medical Center. The predominant antigenic phenotype of hairy cells was CD45 (leukocyte common antigen)+, CD45Ra (4KB5, MB1, MT2)+, L26+, CDw75 (LN1)+, CD74 (LN2)+, LN3+, MB2+, CD45RO (UCHL1)-, MT1-, CD15 (Leu-M1)-, neuron-specific enolase (NSE)-, epithelial membrane antigen-, and CD30 (Ber-H2)-. The immunophenotype of neoplastic monocytoid B lymphocytes was essentially identical to that of the hairy cells, with one exception: the neoplastic monocytoid B lymphocytes were stained by epithelial membrane antigen in seven cases. An interesting observation was the staining by anti-muscle-specific actin of the neoplastic cells of MBCL in 53% of cases, but of none of the cases of HCL. The results of our study (1) indicate that HCL and MBCL can be immunophenotyped reliably on fixed tissue samples, (2) further confirm the proposed lineage relationship between these two lymphoproliferative disorders, and (3) indicate that decalcification of bone marrow biopsies does not adversely affect the immunoreactivity of hematopoietic-associated antigens.     

Further evidence that "malignant angioendotheliomatosis" is an angiotropic large-cell lymphoma

Malignant angioendotheliomatosis is a rare, generally fatal disease characterized by a multifocal proliferation of neoplastic mononuclear cells within the lumens of small blood vessels. Although the disease primarily involves the vasculature of the skin and central nervous system, vascular involvement of other organs may occur and may produce a variety of clinical findings. Some early investigators concluded that malignant angioendotheliomatosis was a neoplasm of endothelial cells, but recently others have suggested that it is of hematopoietic origin. We have studied three patients with the disease and have characterized the immunophenotype of the neoplasm on cryostat-cut fresh-frozen tissues. A detailed antigenic phenotyping of neoplastic lymphoid cells showed that one patient had the immunophenotype T11+, Leu-1+, Leu-3+, Leu-2+, B1-, B2-, SIg-, LN1-, LN2-, the predominant phenotype for peripheral T-cell lymphoma; the others had T11-, Leu-1-, Leu-3-, Leu-2-, B1+, B2+, SIg+, LN1+, LN2+, consistent with a B-cell-derived lymphoma. On the basis of our results, we suggest that angiotropic (intravascular) large-cell lymphoma would be more appropriate than malignant angioendotheliomatosis as a name for this disease.     

Cytomegalovirus-infected cells express Leu-M1 antigen. A potential source of diagnostic error.

The authors examined cytomegalovirus (CMV)-infected tissues and Hodgkin's Disease (HD) cases with immunohistochemical assays for Leu-M1 and CMV. The cytologic characteristics were correlated with immunostaining patterns. Cytomegalovirus-infected cells in lymph node, lung, and esophagus sections showed Cowdry type A inclusions, and many had granular cytoplasmic inclusions. All infected cells showed nuclear staining with an anti-CMV antibody. Leu-M1 reacted with CMV-infected cells in cytoplasmic areas, particularly near the nucleus simulating the characteristic staining pattern of Reed-Sternberg (R-S) cells. Cytoplasmic staining intensified as the intranuclear inclusions increased in size. Reed-Sternberg cells showed characteristic Leu-M1 positivity along the cell membrane and golgi zone. At times, Leu-M1 staining of CMV-infected cells was indistinguishable from that of R-S cells. None of the R-S cells reacted with the antibody to CMV. Recognition of the reactivity of Leu-M1 with CMV-infected cells is important in avoiding misdiagnosis of CMV lymphadenitis as HD.     

T-cell lymphoblastic leukemia/lymphoma presenting in a recurrent thymoma

A lymphoblastic malignancy presented as the lymphoid component of a recurrent invasive lymphocyte-rich thymoma that had been previously resected and treated with chemotherapy. This high grade lymphoid neoplasm concurrently involved mediastinal nodes and subsequently disseminated to pleural fluid and peripheral blood. Lymphocytes with convoluted nuclei demonstrated a T-lymphoblastic phenotype (UCHL1+, Leu-22+, TdT+) by immunohistochemical studies. T-cell lymphoblastic leukemia/lymphomas in this clinical setting have not been reported, and this case suggests that neoplastic transformation of lymphocytes may occur in longstanding refractory thymomas.     

Monoclonal antibody OPD4 detects neoplastic T cells but does not distinguish between CD4 and CD8 neoplastic T cells in paraffin tissue sections.

Monoclonal antibody (MoAb) OPD4, reported to preferentially react with benign CD4 T cells in formalin-fixed tissue sections, was examined for its reactivity with 56 T-cell neoplasms after formalin or Bouin's fixation to determine if it also preferentially detects neoplastic CD4 T cells in paraffin tissue sections. Monoclonal antibody OPD4 did not preferentially detect neoplastic CD4 T cells, since it reacted with 22 of 38 (58%) CD4-positive compared with nine of 14 (64%) CD4-negative T-cell neoplasms. However, MoAb OPD4 appears to detect neoplastic T cells in Bouin's-fixed (11 of 20 cases [55%]) about as well as in formalin-fixed (20 of 32 cases [63%]) tissues. Since MoAb OPD4 does not preferentially react with neoplastic CD4 T cells, the utility of this MoAb as a pan-T-cell marker in routinely processed tissues was also explored and compared with that of Leu-22, UCHL-1, and CD3. All four antibodies reacted with approximately the same percentage of T-cell malignancies (51% to 57%). However, examination of different clinicopathologic groups and types of fixative highlighted differences. Monoclonal antibodies OPD4 and Leu-22 reacted with 62%, while CD3 detected only 41% of formalin-fixed, postthymic T-cell neoplasms. OPD4, UCHL-1, and CD3 each reacted with 55%, but Leu-22 recognized only 45% of Bouin's-fixed, postthymic T-cell malignancies. OPD4 reacted with none, but CD3 reacted with all four T-cell lymphoblastic lymphomas. Various antibody combinations were examined to determine an optimal panel for the recognition of T-cell neoplasms in paraffin sections. The combination of MoAbs OPD4 and Leu-22 detected 86% of postthymic T-cell neoplasms in formalin-fixed tissue sections. Furthermore, MoAb OPD4 appears to be relatively specific for T-cell neoplasms, detecting 31 of 56 (55%) T-cell malignancies, while only reacting with two of 39 (5%) B-cell neoplasms. Therefore, while not preferentially reactive with neoplastic CD4 T cells, MoAb OPD4 may be useful as a pan-T-cell marker of postthymic T-cell neoplasms in routinely processed, formalin-fixed tissues, especially when used in conjunction with MoAb Leu-22.