Splenic involvement by aggressive malignant lymphomas of B-cell and T-cell types. A morphologic and immunophenotypic study.

To determine whether there are any consistent morphologic differences between B-cell and T-cell aggressive non-Hodgkin's lymphomas of the spleen, the authors analyzed 16 spleens involved by mixed cell (1 case) or large cell (15 cases) lymphomas. Immunologic data were derived from cell suspensions or frozen tissue in each case. Five cases had a T-cell phenotype, and 11 were B-cell. Morphologic features favoring a T-cell phenotype included epithelioid histiocytic reactions, confinement of the lymphomas to the splenic T-zones (periarteriolar lymphoid sheath and marginal zone), and clear cell or polymorphous cytologic features. Features favoring a B-cell phenotype included multiple discrete nodules in the white pulp, large coalescent tumor nodules in association with small lymphocytic lymphoma, and large non-cleaved or immunoblastic plasmacytoid cytologic characteristics. Four cases were unusual because most neoplastic large cells were distributed diffusely or formed only small aggregates in the red pulp without definite tumor masses or nodules involving the white pulp. Because of this distribution and the frequently encountered erythrophagocytosis by benign-appearing histiocytes, these cases resembled malignant histiocytosis. A T-cell phenotype was predicted for all four cases; however, only one case, a lymphoma with polymorphous cytologic characteristics, was of T-cell lineage. The other three cases were of B-cell lineage. The authors' results indicate that in most instances the B-cell or T-cell nature of aggressive splenic lymphomas is predictable from the distributional and cytologic features. As in lymph nodes, there are cases for which the morphologic characteristics of B-cell and T-cell lymphomas are indistinguishable.     

Surface markers and functional properties of non-Hodgkin's lymphoma cells in relation to histology.

Cells from 32 adult patients with non-Hodgkin's lymphoma were studied with respect to surface markers and functional properties in short-term culture. Twenty-six lymphomas were of B-cell origin, including all nodular and diffuse lymphocytic lymphomas. Three tumors were of T-cell origin (one histiocytic lymphoma and two undifferentiated lymphomas). In the remaining three cases (histiocytic lymphomas) the immunological nature of the tumor cells could not be determined. All reactivity to mitogenic stimuli of cells from B-cell lymphomas was due to residual normal T cells. In follicular lymphocytic lymphomas more reactive T cells prevailed among the malignant B cells than in diffuse lymphocytic lymphomas. Heterogeneity among B-cell lymphomas was indicated by differences in intensity of fluorescence with anti-Ig reagents and in stimulatory capacity in mixed lymphocyte culture. T-cell lymphomas were characterized by high percentages of T cells together with impaired responses to stimuli. The results of immunological studies correlated well with the histological classifications of Rappaport, Lukes and Lennert.     

Surface phenotyping, histology and the nature of non-Hodgkin lymphoma in 157 patients.

In a study of 157 patients with lymphoid malignancy, the phenotype of the tumour cells was correlated with the histological classification of the tumour using the Rappaport and the Kiel classifications. The markers used included E, Fc gamma, Fc micron (IgM) and C3d rosetting, estimation of SIg and CyIg, and tests for the expression of HTLA, Ia and ALL. Repeat biopsy specimens were studied in 23 of these patients. The phenotypic features of lymphoblastic malignancy indicated B-cell, T-cell and ALL-positive null-cell tumours in this group. Immunoblastic lymphomas were predominantly of non-capping B-cell type, but T-cell immunoblastic lymphoma occurred in 2 patients. Immunoblastic lymphomas of receptor-silent cells occur, and are ALL- and HTLA-negative. In the category of diffuse, poorly differentiated lymphocytic lymphomas, most cases are of centroblastic and centrocytic tumour of diffuse type, but pure centrocytic tumours and centroblastic tumours occur. The dominant phenotype in this group is of B cells expressing C3d receptors. Nodular poorly differentiated lymphocytic lymphomas (Rappaport) are classified as centroblastic and centrocytic follicular (Kiel) and most express SIg+ C3d+ phenotype. The frequency of this phenotype appeared the same in both diffuse and nodular poorly differentiated lymphocytic neoplasms. The Rappaport group of diffuse well-differentiated lymphocytic lymphoma includes 2 Kiel categories, malignant lymphoma lymphocytic, and malignant lymphoma lymphoplasmacytoid. Cells of the former tumour were considered to be immature B cells resembling those seen in CLL, and characteristically expressing SIg weakly, with a high frequency of single kappa light chain. Cells of the latter tumour are by contrast mature, and are related to the centroblastic and centrocytic follicular tumour by their histogenesis and phenotypic features. Repeat biopsy examinations indicate that T-cell predominance occurs in the prodromal phase of B-cell-predominant tumours of SIg+ C3d+ phenotype. It is concluded that non-Hodgkin lymphoma can be divided into 2 categories: (1) tumours of immature immunologically incompetent cells of lymphoblastic histology and with phenotypic features akin to T, B and Null-cell ALL, and (2) tumours of differentiated lymphocytes expressing the phenotypic features of B lymphocytes, with maturation arrested at one of several stages of an antigen-dependent immune response.     

Nodular lymphocytic lymphoma eventuating into diffuse histiocytic lymphoma: immunoperoxidase demonstration of monoclonality.

The patient described here had a nodular, poorly differentiated lymphocytic lymphoma associated with a serum monoclonal protein, IgG lambda. Following a three year period of radiation-induced clinical remission she developed generalized diffuse histiocytic lymphoma. Direct immunoperoxidase staining of the tissue sections demonstrated that the neoplastic cells of each biopsy only contained IgG lambda immunoglobulin, identical to the serum monoclonal protein. This is presumptive evidence that these two histopathologically distinctive malignant lymphomas, occurring consecutively in the same patient, were responsible for the synthesis and secretion of the same serum M component. This strongly suggests that both lymphoid neoplasms arose from the same malignant clone. The results 1) confirm the light microscopic observation that nodular lymphocytic lymphoma may progress to diffuse histiocytic lymphoma and 2) offer further evidence that histiocytic lymphomas arising in patients with previous B cell malignancies are most probably related to the original B cell proliferation and do not represent the emergence of a second, separate malignant clone.     

Lectin binding properties of human follicular center lymphocytes and follicular (nodular) lymphomas

The distribution of lectin binding receptors in normal human lymphoid tissue and follicular (nodular) lymphoma was studied in tissue sections using a panel of lectin-peroxidase and lectin-fluorescein conjugates: Concanavalin A (Con A), Peanut agglutinin (PNA), Lotus tetragonolobus agglutinin (LTA), Soybean agglutinin, Ulex europeus and Bandeiraea simplicifolia. Two lectins studied, PNA and LTA were found to bind selectively to the cell membranes of follicular centre lymphocytes in normal lymphoid tissue, and to the neoplastic cells of follicular (nodular) lymphomas. Con A, in contrast, bound selectively to follicular centre macrophages (tingible body cells) and identified in follicular (nodular) lymphomas a population of dendritic-like cells not otherwise recognized and possibly corresponding to dendritic cells identified ultrastructurally. Follicular (nodular) lymphomas share the lectin binding properties of non-neoplastic follicular centres. The expression of receptors for lectins with blood group activity (PNA T-like, LTA H-like) on follicular lymphocytes may play a role in follicle formation.     

T-cell-rich lymphoproliferative disorders. Morphologic and immunologic differential diagnoses

To differentiate peripheral T-cell lymphomas (PTCL), the authors evaluated the results of T11 monoclonal antibody studies on consecutive cell suspensions prepared from 509 lymph nodes from various lymphoproliferative disorders (LPD). They used T11 (CD2) positivity to identify those LPD in which the content of T cells was high. There were 266 (52%) cell suspensions which contained more than 50% T11-positive cells. More than 75% of the following non-Hodgkin's lymphomas had over 50% T11-positive cells: diffuse mixed cell (DM), diffuse atypical poorly differentiated lymphocytic and lymphoblastic lymphomas; mycosis fungoides; and true histiocytic lymphoma. Eleven cell suspensions had more than 90% T11-positive cells; four were involved by B-cell lymphomas. The cell suspensions prepared from nine of 14 diffuse large cell lymphomas of the T-cell type had more than 50% T11-positive cells. Of these, three of five cases of the polymorphous subtype had fewer than 50% T11 cells, but six of seven lymph nodes of the clear-cell type had more than 50% T11-positive cells. Each of seven DM samples of the T-cell type contained over 50% T11 cells; none had a polymorphous appearance. In the 112 cases of reactive LPD studied, more than 75% of cases of necrotizing lymphadenitis, dermatopathic lymphadenitis, angioimmunoblastic lymphadenopathy, and those with lymph nodes with no specific reactive pattern had more than 50% T11-positive cells. The authors' findings indicate that T11 positivity is a reliable T-cell marker in reactive and neoplastic LPD except for those cases of PTCL with a polymorphous appearance; these tend to lose T11-expression. A multi-parameter diagnostic approach is required in the following LPD: (1) PTCL which are T11-negative; (2) PTCL of small lymphocytic type having an unremarkable T-cell phenotype; (3) SIg-negative B-cell lymphomas which are rich in nonneoplastic T cells; (4) non-Hodgkin's lymphomas with minimal disease which are rich in reactive T cells; and (5) polymorphous large cell proliferations.     

Terminal deoxynucleotidyl transferase activity in lymphoma.

Terminal deoxynucleotidyl transferase (TdT) was estimated in the tissues of 42 patients with lymphoma, whose cells were also typed by the use of surface markers. Four of the 8 patients with T-cell lymphoma were TdT+ including patients whose lymph nodes showed an undifferentiated or poorly differentiated appearance. The TdT- T-cell lymphomas included cases with diffuse histiocytic Sezary cell, diffuse, poorly differentiated and angio-immunoblastic histology. The tissues of 31 patients with B-cell lymphoma were invariably TdT-, whether the histology was poorly differentiated, well differentiated, nodular, diffuse, histiocytic or Burkitt type, and including cases with about equal proportions of T and B cells, and those whose cells showed non-capping and capping surface immunoglobulin. Hodgkin's tissue was also invariably TdT-. We conclude that estimation of TdT in tissues of patients with malignant lymphoma may be a useful test in diagnosing the T-cell lymphoma, particularly in patients with tumours of undifferentiated or poorly differentiated histology.     

Correlation of surface receptors with histological appearance in 29 cases of non-Hodgkin lymphoma.

The receptor patterns of cell suspensions from 29 cases of non-Hodgkin lymphoma were correlated with the histology of the nodes from which the cells were taken. Twenty-two were judged to be predominantly or largely B-cell, and because of this preponderance these were divided by a method based on the distribution of surface immunoglobulin and the expression of Fc and C3 receptors. "Mature" B-cell and B-mixed tumours showing capping surface Ig with Fc and/or C2 receptors correlated well with a nodular growth pattern, and consisted of what Rappaport (1966) calls "poorly differentiated" lymphocytes equivalent to the "small cleaved" cells as defined by Lukes and Collins (1975). Ten of the 14 patients in this receptor category are alive between 12 and 30 months after diagnosis. Receptor-silent and "immature" B-cell tumours with non-capping surface Ig correlated predominantly with the Rappaport histiocytic lymphoma and Lukes and Collins' large cleaved and large non-cleaved lymphomas, though these histological categories also included a wide variety of other receptor types such as T-cell, Receptor-overlap and the single true Macrophage tumour.Five of the 11 patients with receptor-silent or immature B-cell tumours are alive between 7 and 15 months after the diagnosis. Diffuse mixed and diffuse poorly differentiated lymphocytic lymphomas in Rappaport's classification correlated poorly with receptors, mature and immature B-cell tumours being equally represented.     

Intra-tumoral cytolytic cells: Pattern of distribution in B-cell non Hodgkin’s lymphoma

Non-Hodgkin s lymphomas (NHLs) constitute a heterogeneous group of lymphoid neoplasms and a majority of them in India are of B-cell phenotype. Varying numbers of T lymphocytes and natural killer (NK) cells are consistently present within the lymph nodes (LNs). The role of these reactive cells is becoming understood. TIA-1 is a cytotoxic granule associated RNA binding protein, the expression of which is restricted to cytotoxic T lymphocytes (CTLs) and NK cells. Snap frozen lymph node biopsies obtained from 41 B-cell NHLs were localized for intra-tumoral TIA-1 + cytolytic cells by immunohistochemistry. Distribution of T cell subsets and NK cells were also quantified. Cells expressing TIA-1 antigen was observed in all the cases, seen as a strong granular cytoplasmic signal. Results indicate significantly higher number of TIA-1 cytolytic cells outside (periphery of the follicle and interfollicular areas) than within the neoplastic follicle in follicular lymphomas (p<0.001). In small lymphocytic lymphomas, cytolytic cells were mainly seen as uniformly scattered single cells, distributed throughout the tumor environment. In mantle cell and diffuse large B-cell lymphomas these were most often seen as small clusters and less frequently as singly scattered cells. Higher numbers of CD4 + than the CD8 + T cells were observed in most cases. Contrary to the follicles in follicular hyperplasia, CD57 + NK cells were predominantly observed outside the neoplastic follicle in follicular lymphomas (FLs). These results outline specific interactions between the potential anti-tumoral cytolytic and the malignant cells of B-cell NHLs.     

B-cell lymphomas morphologically resembling T-cell lymphomas

Seven cases of B-cell lymphoma that morphologically resembled T-cell lymphoma are described. These cases are of four morphologic types: atypical poorly differentiated lymphocytic lymphoma (PDLL) with convoluted nuclei, "Lennert's" lymphoma, mixed lymphocytic-"histiocytic" lymphoma with large variation in size of abnormal cells, and "histiocytic" lymphoma with large multilobed nuclei. These cases add further support to the belief that morphologic criteria alone are not sufficient for accurate immunologic classification of the malignant lymphomas since they may represent a distinct clinicopathologic entity.     

Non-Hodgkin's lymphoma of Waldeyer's ring and nasal cavity. Clinical and immunologic aspects

Twenty-nine cases of non-Hodgkin's lymphoma of Waldeyer's ring (W-NHL) and nasal cavity or paranasal sinus (N-NHL) were studied for tumor-surface marker phenotype and histopathologic correlation with clinical features. Immunostaining procedures on tissue sections by using xenoantisera and monoclonal antibodies to human B- and T-cells enabled the authors to demonstrate precise surface marker phenotypes of tumor cells and, moreover, the histologic localization of normal or neoplastic B- and T-cells in preserving the original structure of lymphoid organs or tumor tissues. In 22 cases of W-NHL, 19 (86%) had B-cell markers and 3 (14%) had T-cell markers, whereas 6 of 7 cases (86%) of N-NHL had T-cell markers. Tumor cells in T-cell lymphomas in W-NHL and N-NHL reacted with antibodies to peripheral T-cells except one case of W-NHL. Rappaport "histiocytic" subtype was heterogeneous with respect to both surface marker characteristics and morphologic features, i.e., seven had B-cell markers and four had T-cell markers, and they were all subdivided into "large cell" or "large cell, immunoblastic" in Working Formulation and "large cell" or "pleomorphic" in Lymphoma Study Group classification. The actuarial survival curve for all T-cell lymphoma patients was characterized by a rapid initial decline and a subsequent plateau, which contained two of the long survivors. In contrast, the B-cell lymphoma group had a more graded decline. The median and actuarial survivals of the T-cell lymphoma group were far inferior to those for the lymphoma group that expressed B-cell markers.     

Hepatosinusoidal leukaemia/lymphoma consisting of epstein-barr virus-containing natural killer cell leukaemia/lymphoma and T-cell lymphoma; mimicking malignant histiocytosis

Previously diagnosed cases of hepatosinusoidal T-cell lymphoma and malignant histiocytosis (MH) may include lymphoid neoplasms of natural killer (NK) cell lineage associated with Epstein-Barr virus (EBV). Such hepatosinusoidal neoplasms were found to demonstrate hepatomegaly but not lymphadenopathy, and all were diagnosed by a liver biopsy. Sixteen adult patients diagnosed with hepatosinusoidal leukaemia/lymphoma (six NK-cell leukaemia/lymphomas [NKLLs], five instances of MH, three T-cell malignant lymphomas [T-MLs], and two adult T-cell leukaemia/lymphomas [ATLLs] were examined for EBV by in situ hybridization, then were studied immunohistochemically and subjected to a DNA analysis. Among our five patients with MH, neoplastic cells showed T-cells, but no histiocytic markers, and they were considered to have either a T-cell or NK-cell lineage. All NKLLs, MHs and T-MLs, except for ATLLs accompanied by reactive hemophagocytic histiocytes, varied in number in each case. In situ hybridization revealed the presence of EBV in the nuclei of atypical cells in all of the six lymphoid neoplasms of NK-cell lineage. Each case of MH and each T-ML which represented EBV demonstrated no definite T-cell or histiocytic markers. Patients with ATLL did not reveal EBV. In all patients with hemophagocytosis, EBV was present in the nuclei of the neoplastic lymphocytes, but not in the hemophagocytic cells. Finally, the 16 cases were reclassified into eight cases with EBV -containing NKLLs, six T-MLs, and two ATLLs. In addition, no true histiocytic neoplasms were observed. The mechanism of hemophagocytosis may be therefore the production of lymphokines (macrophage-activating factors) by neoplastic lymphocytes. EBV-associated hepatosinusoidal leukaemia/lymphoma may thus contain a lymphoid neoplasm of NK-cell lineage, which made it difficult to be distinguished from the previously designated malignant histiocytosis.     

Mantle-zone lymphoma. An immunohistologic study

Mantle-zone lymphoma (MZL) is a histologically distinctive variant of follicular lymphocytic lymphoma which is characterized by a proliferation of atypical small lymphoid cells as wide mantles around benign-appearing germinal centers. Immunoperoxidase stains were performed on fixed and processed lymph nodes from four patients with MZL. Three cases were of the intermediate lymphocytic type, and one was of the small cleaved lymphocytic type. In all cases, the small lymphoid cells of the mantle zones did not stain. A monoclonal population (IgM, lambda) of plasma cells and large lymphoid cells was demonstrated predominantly in the paracortical areas in one case. In all cases, small numbers of plasma cells and large lymphoid cells in the follicle centers stained in a polyclonal pattern, confirming the benign nature of the centers. These findings suggest that follicular lymphomas of the mantle-zone type are exceptions to the theory that follicular B-cell lymphomas are derived from follicular center cells. Apparently, the lymphoid cells of MZL home to the mantle zones of secondary follicles, where they surround, proliferate, and eventually obliterate residual benign germinal centers.     

Regulation of TCL1 expression in B- and T-cell lymphomas and reactive lymphoid tissues

Chromosomal rearrangements observed in T-cell prolymphocytic leukemia involve the translocation of one T-cell receptor gene to either chromosome 14q32 or Xq28, deregulating the expression of cellular protooncogenes of unknown function, such as TCL1 or its homologue, MTCP1. In the human hematopoietic system, TCL1 expression is predominantly observed in developing B lymphocytes, whereas its overexpression in T cells causes mature T-cell proliferation in transgenic mice. In this study, using a newly generated monoclonal antibody against recombinant TCL1 protein, we extended our analysis mainly by immunohistochemistry and also by fluorescence-activated cell sorting and Western blot to a large tumor lymphoma data bank including 194 cases of lymphoproliferative disorders of B- and T-cell origin as well as reactive lymphoid tissues. The results obtained show that in reactive lymphoid tissues, TCL1 is strongly expressed by a subset of mantle zone B lymphocytes and is expressed to a lesser extent by follicle center cells and by scattered interfollicular small lymphocytes. In B-cell neoplasia, TCL1 was expressed in the majority of the cases, including lymphoblastic lymphoma, chronic lymphocytic leukemia, mantle cell lymphoma, follicular lymphoma, Burkitt lymphoma, diffuse large B-cell lymphoma (60%), and primary cutaneous B cell lymphoma (55%). TCL1 expression was observed in both the cytoplasmic and nuclear compartments, as confirmed by Western blot analysis. Conversely, TCL1 was not expressed in Hodgkin/Reed-Sternberg cells, multiple myelomas, marginal zone B-cell lymphomas, CD30+ anaplastic large cell lymphoma, lymphoblastic T-cell lymphoma, peripheral T-cell lymphoma, and mycosis fungoides. These data indicate that TCL1 is expressed in more differentiated B cells, under both reactive and neoplastic conditions, from antigen committed B cells and in germinal center B cells and is down-regulated in the latest stage of B-cell differentiation.     

Immunohistochemical Analysis of Cyclin D1 Protein in Hematopoietic Neoplasms with Special Reference to Mantle Cell Lymphoma

Immunohistochemical expression of PRAD1/cyclin D1 protein has been investigated in 106 tissue specimens of 104 cases of lymphoma, non-neoplastic lymphoid disorders and other hematologic malignancies by employing the monoclonal antibody 5D4 with formalin-fixed paraffin-embedded sections, using the microwave oven heating method. Positive neoplastic cells were found in 60 (74%) of 81 cases of non-Hodgkin's lymphoma. The positivity pattern was nuclear in 17 (85%) of 20 cases of mantle cell lymphoma in which cytoplasmic staining was also seen. This pattern of cyclin D1 positivity was in contrast to the negative staining of normal reactive mantle zones. In the other cases, positivity appeared to lie within the cell cytoplasm without nuclear staining, and most of the nodal follicular and diffuse B-cell lymphomas variously expressed PRAD1/cyclin D1. In contrast, the reaction was absent in a significant number of T-cell and extranodal B-cell lymphomas. Immunolocalization of PRAD1/cyclin D1 expression appears to be a useful diagnostic adjunct to discriminate mantle cell lymphoma from other non-Hodgkin's lymphomas.     

Nodal B-Cell Lymphomas in Japan -- Particularly in Tohoku District --

There are different frequencies in the immunological phenotypesof malignant lymphomas in Tohoku and Kyushu districts of Japan.In the Tohoku district, the northern area of Honshu, B-celllymphomas are more preponderant than T-cell lymphomas. Thisis just the reverse on the islands of Kyushu and Shikoku. Histologicallydiffuse lymphoma of large cell type, formerly termed reticulumcell sarcoma or histiocytic lymphoma, was the most frequent(48%) among B-cell lymphomas. It is characteristic of B-celllymphoma that immunoglobulin is produced in either or both thecellular surface and cytoplasm. Cytoplasmic IgM in lymphomacells was mainly detected by an electron microscopic enzyme-labeledmethod. Cytoplasmic-Ig was present both in the nuclear membraneand endoplasmic reticulum. This technique is particularly usefulin medium-sized lymphoma cells because of the scanty cytoplasmicrim making light microscopic evaluation difficult. Histological transition from follicular to diffuse pattern ischaracterized by a change of cellular arrangement from labyrinth-likecellular connections in follicular lymphoma to more simple connectionsin diffuse lymphoma. The transition is also supported by thefact that a higher deoxyribonucleic acid content is observedin large cells than medium-sized cells in follicular lymphoma.The data also supports the hypothesis that a diffuse lymphomaevolved from follicular lymphoma mainly occurs in cases of largecell lymphomas.     

Heterogeneous in situ immunophenotyping of follicular dendritic reticulum cells in malignant lymphomas of B-cell origin

The phenotype of follicular dendritic reticulum cells (DRC) was analyzed with monoclonal antibodies (DRC-1, OKB7, BA-2, Leu-M3, and antidesmoplakin 1 and 2) in 28 frozen biopsy specimens of both morphologically and phenotypically analyzed B-cell lymphomas and 21 normal or reactive controls. The former included 15 follicular center cell lymphomas (FCCL), four intermediately differentiated lymphocytic lymphomas (ILL), four mantle zone lymphomas (MZL), and five well-differentiated lymphocytic lymphomas (WDLL). In controls, DRC-1+ and OKB7+ DRC were localized in both follicular centers (FC) and mantle zones (MZ), but BA-2+ and Leu-M3+ DRC were confined to FC only. FCCL were usually accompanied by DRC-1+, OKB7+, and BA-2+ DRC, and either lost or maintained positively with Leu-M3 from case to case. By contrast, MZL consistently lacked BA-2+ and Leu-M3+ DRC, and was associated with DRC-1+ and OKB7+ DRC only. Desmoplakin-positive DRC occurred in variable proportions in both FCCL and MZL. As opposed to FCCL and MZL, all WDLL and all but one of the ILL (associated only with DRC-1+, OKB7+, and desmoplakin+ DRC) did not show any DRC as identifiable with the antibody panel used. Remarkably, the difference in the distribution of BA-2+ and Leu-M3+ DRC in the normal FC and MZ appears to be maintained in their neoplastic counterparts (FCCL and MZL) also. Such a difference represents an example of the possible interactions between lymphoma cells of different phenotype and their microenvironment, as portrayed by phenotypically heterogeneous DRC.     

Malignant lymphomas of the thyroid: a clinical pathologic study of 35 patients including ultrastructural observations.

The clinical and pathologic findings for 35 patients with malignant lymphoma presenting in the thyroid are reviewed. The lymphomas tended to occur in females with a median age of 65 years and clinically were manifested by a mass in the neck. The majority of patients were euthyroid and thyroid scans demonstrated cold nodules. In none of the patients was there clinical suspicion of lymphoma prior to surgery. Thirty-four of the cases were histiocytic lymphomas; the one exception; a patient with nodular poorly differentiated lymphocytic lymphoma, had histiocytic lymphoma in a subsequent biopsy of the soft tissues of the neck. Although classified as histiocytic, the lymphomas had the histologic and ultrastructural features of transformed lymphocytes or immunoblasts. Lending possible additional credence to the immunoblastic nature of these lymphomas was the histologic documentation of chronic lymphocytic thyroiditis in all 27 cases where residual thyroid parenchyma remained. This relationship suggests possible evolution of thyroid lymphomas from chronic lymphocytic thyroiditis and probably is analogous to the malignant lymphomas developing in other altered immune states, including Sjogren's syndrome. In the current study the overall 5-year survival was 54%. Patients under age 65, without local soft tissue extension or regional lymph node involvement, and with stage I disease survived the longest; a nodular histologic pattern also appeared to favorably influence the prognosis. Improved staging procedures and newer modes of therapy appear essential, particularly for those patients with clinical stage II disease and with local extension to soft tissues.     

Clonal immunoglobulin gene rearrangements and normal T-cell receptor, bcl-2, and c-myc genes in primary cutaneous B-cell lymphomas

Fourteen cases of primary cutaneous B-cell lymphomas were investigated at the immunohistochemical and molecular level to further characterize this newly defined entity. Neoplastic cells from all cases, phenotyped with a panel of monoclonal antibodies, were positive for HLA-DR, for the B-cell markers CD19, CD22, but not CD23 (except one case), and negative for the T-cell marker CD2. Monoclonal immunoglobulin light chains were demonstrated in six cases. The reactivity with the Ki-67 monoclonal antibody indicated that the neoplastic cells are proliferating. In five biopsies the presence of dendritic cells infiltrating the neoplastic areas was revealed using the monoclonal antibody Kim4b. By Southern blot analysis, clonal rearrangement of the immunoglobulin heavy chain gene (involving one or both alleles) was shown in 12 of 14 cases and of the light chain genes in 13 cases. The bcl-2 oncogene, normally involved in nodal follicular lymphomas, was in germ-line configuration. The c-myc and the beta and gamma chain genes of the T-cell receptor were also in the germ-line configuration. None of the cases presented Epstein-Barr virus sequences. These data indicate that primary cutaneous lymphomas of B-cell origin share morphological and phenotypic similarities with the nodal B-cell lymphomas of follicular histotype, are proliferating, and express in 45% of cases clear monoclonal immunoglobulin light chain; the molecular analysis confirms the B-cell derivation and the monoclonal nature of this neoplasia; it also shows that neither bcl-2 nor c-myc oncogenes are involved and that no inappropriate rearrangements of the T-cell receptor genes are found in this lymphoma.     

In situ immunologic characterization of follicular lymphomas

Surface markers were studied in a series of follicular lymphomas with immunofluorescence on frozen sections (39 cases) and on cell suspensions (21 cases), and with immunoperoxidase on frozen sections using a panel of 15 monoclonal antibodies (17 cases). With immunofluorescence on frozen sections, 22/39 cases showed monotypic sIg (IgMK: 14 cases, IgML: 7 cases, M: 1 case). In the remaining 17 cases the neoplastic follicles were negative. Nevertheless, even if sIg is not detected, the absence of an extracellular immunoglobulin network is indicative of the neoplastic, and not of the reactive nature of lymphoid follicles. The results obtained with immunofluorescence on frozen sections and on cell suspensions were identical in about half of the cases. In 9/21 cases monotypic sIg were detected by only one of these two methods. All the 17 cases studied with immunoperoxidase on frozen sections using monoclonal antibodies demonstrated monotypic sIg. On low magnification 6/17 sIg+ exhibited a nodular staining pattern while 7/17 cases this staining was diffuse. In 4/17 cases the staining pattern for heavy and light chains was different. A thin mantle zone, with sIgM plus sIgD cells, was observed in only 4 cases. Anti-HLA-DR and Leu-10 were positive in all cases. T cells positive for OKT3 were mainly distributed in the interfollicular areas; OKT4 + cells outnumbered OKT8 + cells. Within the neoplastic follicles, T cells stained mainly for OKT4 and OKT8 + cells were scarce. Leu-7 + cells predominated within the neoplastic nodules in 5 cases. With the anti-dendritic reticulum cell monoclonal antibody, all 17 cases showed a network, usually more loosely arranged than in reactive follicles. In 4 cases, of follicular and diffuse lymphoma, this network was extremely dissociated and in some areas these cells were scanty or lacking. We concluded that immunoperoxidase on frozen sections, using monoclonal antibodies, appears to be the most reliable method for the immunological phenotyping of follicular lymphomas.