Fecal microbiota diversity in survivors of adolescent/young adult Hodgkin lymphoma: a study of twins.

BACKGROUND: Adolescent/young adult Hodgkin lymphoma (AYAHL) survivors report fewer exposures to infections during childhood compared with controls, and they have functional lymphocyte aberrations. The gut microbiota plays a central role in immunity. METHODS: We investigated whether fecal microbial diversity differed between 13 AYAHL survivors and their unaffected co-twin controls. Pyrosequencing of fecal bacterial 16S rRNA amplicons yielded 252 943 edited reads that were assigned to species-level operational taxonomic units (OTUs) and standardised for sequencing depth by random sampling. Microbial diversity was compared within vs between twin pairs and by case-control status. RESULTS: The number of unique OTUs was more similar within twin pairs compared with randomly paired participants (P=0.0004). The AYAHL cases had fewer unique OTUs compared with their co-twin controls (338 vs 369, P=0.015); this difference was not significant (169 vs 183, P=0.10) when restricted to abundant OTUs. CONCLUSION: In this small study, AYAHL survivors appear to have a deficit of rare gut microbes. Further work is needed to determine if reduced microbial diversity is a consequence of the disease, its treatment, or a particularly hygienic environment.

Long-term follow-up of patients with low-grade malignant lymphomas treated with doxorubicin-based chemotherapy or chemoimmunotherapy.

PURPOSE: We reviewed survival data of patients with low-grade lymphoma entered on Southwest Oncology Group (SWOG) lymphoma trials in 1972 to 1983 to determine the utility of doxorubicin-containing therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]) in such patients. PATIENTS AND METHODS: We identified all patients with low-grade lymphoma, no prior therapy, and stage III or IV disease who were treated with full-dose CHOP induction therapy on any arm of SWOG studies 7204, 7426, or 7713. Survival data for this group of patients were correlated with pretreatment prognostic factors, including histology, patient age, sex, symptom status, performance status, bone marrow or extranodal involvement, and the number of disease sites. The effect of maintenance treatment was also assessed. RESULTS: Four hundred fifteen patients met criteria for inclusion in the study group. With median follow-up periods of 12.8 years (maximum, 19.8 years), the median survival duration was 6.9 years. Survival was significantly shorter in patients with follicular mixed or small lymphocytic histology, age greater than 40 years, male sex, B-symptom status, and SWOG performance status greater than 1. Multivariate regression analysis showed histology, age, and sex to be independent predictors of survival. There was no definite survival plateau of cured patients in any subgroup, although the survival curve for follicular mixed histology patients showed long-term survival of approximately 25%. Maintenance therapy did not prolong survival. CONCLUSION: Doxorubicin-containing treatment did not prolong the overall median survival of low-grade lymphoma patients compared with results with less-aggressive programs.

Marginal zone B-cell lymphoma: A clinical comparison of nodal and mucosa-associated lymphoid tissue types. Non-Hodgkin's Lymphoma Classification Project.

PURPOSE: In the International Lymphoma Study Group classification of lymphoma, extranodal marginal zone B-cell lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) type is listed as a distinctive entity. However, nodal MZL is listed as a provisional entity because of questions as to whether it is truly a disease or just an advanced stage of MALT-type MZL. To resolve the issue of whether primary nodal MZL without involvement of mucosal sites exists and whether it is clinically different from extranodal MALT-type lymphoma, we compared the clinical features of these two lymphomas. PATIENTS AND METHODS: Five expert hematopathologists reached a consensus diagnosis of MZL in 93 patients. Seventy-three were classified as having MALT-type MZL because of involvement of a mucosal site at the time of diagnosis, and 20 were classified as having nodal MZL because of involvement of lymph nodes without involvement of a mucosal site. RESULTS: A comparison of the clinical features of nodal MZL and MALT-type MZL showed that more patients with nodal MZL presented with advanced-stage disease (71% v 34%; P =. 02), peripheral lymphadenopathy (100% v 8%; P <.001), and para-aortic lymphadenopathy (56% v 14%; P <.001) than those with MALT-type MZL. However, fewer patients with nodal MZL had a large mass (> or = 5 cm) than those with MALT-type MZL (31% v 68%; P =.03). The 5-year overall survival of patients with nodal MZL was lower than that for patients with MALT-type MZL (56% v 81%; P =.09), with a similar result for failure-free survival (28% v 65%; P =.01). Comparisons of patients with International Prognostic Index scores of 0 to 3 showed that those with nodal MZL had lower 5-year overall survival (52% v 88%; P =.025) and failure-free survival (30% v 75%; P =.007) rates than those with MALT-type MZL. CONCLUSION: Nodal MZL seems to be a distinctive disease entity rather than an advanced stage of MALT-type MZL because the clinical presentations and survival outcomes are different in these two types of MZL. Clinically, nodal MZL is similar to other low-grade, node-based B-cell lymphomas, such as follicular and small lymphocytic lymphomas.

Morphological subclassification of follicular lymphoma: variability of diagnoses among hematopathologists, a collaborative study between the Repository Center and Pathology Panel for Lymphoma Clinical Studies.

A collaborative study between the Repository Center for Lymphoma Clinical Studies and the members of the lymphoma pathology subcommittee of the major cooperative oncology groups was undertaken in an effort to ascertain the reproducibility and the interobserver agreement for the cytologic diagnosis of follicular lymphomas. A group of 105 patients with follicular lymphomas were subclassified by seven hematopathologists according to two methods. In the first method, cases were subclassified according to the Rappaport, Lukes, and Collins, and Working Formulation systems. In these systems, follicular lymphomas are subclassified by estimation of the different cell populations without the actual counting of cells. With this method, great variability in diagnosis was noted. For example: (1) The consensus diagnosis was that of poorly differentiated lymphocytic lymphoma (PDL) in 39 cases, but among the individual pathologists the number of cases thus diagnosed ranged from 24 to 65; (2) In 40 cases, the consensus diagnosis was follicular lymphoma, mixed-cell type; however, all seven pathologists independently agreed on this subtype in only one case; (3) A major disagreement was noted in 39 cases (37%), in which both diagnostic extremes (small cleaved and large noncleaved) were expressed. In the second method, only precise counts of different cells were made, according to a modification of the method recommended by Berard. With this counting method, diagnoses were independently derived based on the counts provided by the seven pathologists for large cleaved, small noncleaved, and large noncleaved cells. The variability in the results was wide also with this second method. For example, the average number of large cells found by each pathologist was ascertained, and the ranges were determined. The average range was 28 cells, which was considered high. The same determinations were performed only for large noncleaved cells, and the range was found to be 15 cells, which was also considered high. When the diagnoses derived from counts of only large noncleaved cells were compared with the traditional, more subjective diagnoses, fairly close agreement was obtained. In summary, the great variability in diagnoses of follicular lymphomas among pathologists may be attributed to the difficulties inherent in accurate determination of cell size and of the precise percentages of different cells. Until solutions to these problems are developed, one can subclassify follicular lymphomas according to the Berard method or the estimation method.

Nodal monocytoid B-cell lymphoma (nodal marginal-zone B-cell lymphoma).

Benign monocytoid B cells are seen in lymph nodes in different types of lymphadenitis and they occur in the form of clusters within and around sinuses and in the interfollicular areas, but rarely completely surround benign follicles to produce a marginal-zone pattern. The cytologic hallmark of these cells is the presence of abundant pale to clear cytoplasm; these cells usually are of medium size, and they have a rather bland-appearing, irregular nuclei with inconspicuous nucleoli. Malignant monocytoid B-cell proliferations in a lymph node have been classified as monocytoid B-cell lymphomas (MBCL), which are now called nodal marginal-zone B-cell lymphoma (MZL) in the World Health Organization (WHO) classification. In the recently published clinical evaluation of the International Lymphoma Study Group classification of non-Hodgkin's lymphoma, 25 of 1,378 cases (1.8%) were classified as primary MZL, whereas four times as many cases (105 or 7.6%) were classified as low-grade mucosa-associated lymphoid tissue (MALT)-type lymphoma. Transformation to large-cell lymphoma at the time of diagnosis was seen in five of 25 (20%) cases of nodal MZL and in 32 of 105 (30%) cases of MALT-type lymphoma. Comparison of the clinical findings at presentation and the survival results indicate that nodal MZL is more aggressive clinically than low-grade MALT-type lymphoma. For example, patients with nodal MZL had a significantly higher incidence of advanced-stage disease, including peripheral and paraaortic lymphadenopathy, than those with MALT-type lymphoma. Moreover, patients with nodal MZL had lower 5-year overall survival and failure-free survival than patients with MALT type lymphoma. When analysis was restricted to those patients with zero to three adverse risk factors in the International Prognostic Index, patients with nodal MZL still had a significantly lower overall and failure-free survival at 5 years than patients with MALT-type lymphoma. We conclude that nodal MZL is a distinctive disease entity and is similar to other low-grade nodal lymphomas, such as the follicular or small lymphocytic lymphomas, but different than MALT-type lymphoma.

Atypical lymphoplasmacytic and immunoblastic proliferation in lymph nodes of patients with autoimmune disease (autoimmune-disease-associated lymphadenopathy).

This study is based on an analysis of the morphologic, clinical, and laboratory findings in 26 patients whose pretherapy lymph node biopsies showed some, but not all, of the diagnostic features of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD). Partial or complete effacement of nodal architecture by a diffuse lymphoplasmacytic and immunoblastic proliferation was a constant histologic finding. In contrast to the findings in AILD, lymphocytic depletion and pronounced arborizing vascular proliferation were often lacking. Clinically, many of the patients had fever, sweats, weight loss, skin rashes, generalized lymphadenopathy, hepatosplenomegaly, and, in some cases, pulmonary infiltrates. Of the 26 patients, 23 had clinical and/or laboratory evidence of autoimmune disease or immune complex disease. In 12 patients (Group I--idiopathic), various autoantibodies or immune complexes were demonstrable, but these patients did not manifest a well-defined immunologic disease or syndrome. In 11 patients (Group II--secondary), the lymphadenopathy occurred secondary to a well-defined, clinically recognized immunologic disease. Three patients (Group III) had neither a well-defined autoimmune disease nor demonstrable autoantibodies, but two of them had a history of exposure to antibiotics. We suggest that patients whose lymph nodes have the morphologic features described here frequently have an autoimmune disorder, and that the pathogenesis of this clinicopathologic picture is probably related to a deficiency in suppressor T-cell function which results in an unopposed proliferation of B cells with autoantibody formation and polyclonal gammopathy. Our observations should stimulate clinicians to consider the possibility of an autoimmune pathogenesis for a lymphadenopathy in which a florid lymphoplasmacytic and immunoblastic proliferation similar to that observed in AILD is demonstrated, even though the sections may not meet all the histologic criteria reported for the diagnosis of AILD. Clinical and laboratory investigations necessary to confirm the presence of autoimmunity are indicated in these cases. Moreover, since there is evidence of genetic factors predisposing to autoimmune disease (17, 43), it would be important to investigate close relatives of patients whose lymph nodes showed the histologic changes described in this paper in prospective studies which include suppressor T-cell function, autoantibodies, HLA type of blood lymphocytes and chromosomal analysis. The median survival of the 23 patients with stigmata of autoimmune disease or immune complex disease was 36 months.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary meningeal small lymphocytic lymphoma.

We report an unusual case of primary meningeal small lymphocytic lymphoma presenting as a solitary large extraaxial mass lesion. Histology revealed a prominent pseudofollicular pattern. There was no evidence of extracranial lymphoma by noninvasive staging procedures. Bone marrow and peripheral blood were also negative.

Kikuchi-Fujimoto disease mimicking malignant lymphoma.

Histiocytic necrotizing lymphadenitis is a rare, benign entity described independently both by Kikuchi and Fujimoto et al. This disease, which has a broad morphologic spectrum, can readily be mistaken for malignant lymphoma. Our report on the morphologic features in 10 selected cases of this disease highlights those features that mimicked lymphoma and those that helped us to make an accurate diagnosis. The distinctive features were (a) pathologic areas, which are pale and do not occupy the entire lymph node; (b) preserved sinuses in the uninvolved areas; (c) prominent mottling by histiocytes or transformed lymphoid cells in the nonpathologic areas; (d) frequent absence of overt necrosis; (e) presence of benign histiocytes with moderate to marked nuclear irregularities and scanty to moderate cytoplasm that resembled cleaved cells; (f) variable amounts of nuclear debris, usually extracellular; (g) presence of so-called plasmacytoid T cells at the periphery of or immediately outside the pathologic areas; (h) moderate numbers of mitotic figures and transformed lymphoid cells of medium and large size (immunoblasts); and (i) absence of inflammatory and granulomatous reaction. Because overt necrosis is often absent and histiocytes resemble cleaved cells, we support the suggestion that this entity should be called "Kikuchi-Fujimoto disease" rather than "histiocytic necrotizing lymphadenitis."

Indolent T-lymphoblastic proliferation: report of a case with a 16-year course without cytotoxic therapy.

T-lymphoblastic lymphoma is a high-grade malignant lymphoma. Clinically indolent T-lymphoblastic proliferations have not been described. We present a case report of an indolent T-cell lymphoblastic proliferation studied by histopathology, immunohistochemistry, flow cytometry, antigen receptor gene rearrangement studies, and cytogenetics. The patient had recurrent masses in the upper aerodigestive tract over a 16-year period, was treated by multiple surgical excisions, and never received either chemotherapy or radiotherapy. A proliferation of lymphoblasts was present histologically. The cells were positive for terminal deoxynucleotidyl transferase, CD1, and CD3, and coexpressed CD4 and CD8. No clonal rearrangements of the T-cell receptor beta or gamma chain genes were identified. Cytogenetic studies revealed a questionable inversion of the short arm of chromosome 9, affecting the 9p21-22 region. Although ectopic thymic tissue was considered, the case was considered to be an indolent lymphoblastic proliferation. It should be recognized that rare lymphoblastic proliferations may not behave in a high grade fashion as typically seen in T-lymphoblastic lymphoma.

Lymphoblastic lymphoma expressing natural killer cell-associated antigens: a clinicopathologic study of six cases.

We describe six patients with lymphoblastic lymphoma (LBL) whose neoplastic lymphoid cells expressed surface antigens associated with natural killer (NK) cells. The six cases were selected from a series of 38 specimens diagnosed as LBL based on morphologic criteria and further subclassified by the use of an extensive panel of monoclonal and polyclonal antibodies. Although the morphologic features in all six cases were similar to those previously reported for LBL, their expression of NK-associated antigens was unique. All cases were positive with anti-Leu 11b, an antibody which appears to define a specific subtype of lymphocytes considered to have NK function; and all cases expressed T11, a T-cell-restricted antigen. The most commonly encountered immunophenotype of our cases of LBL was: Leu 11b+, T11+, Leu7+, TdT+, Leu 3a+, Ia+, pre-B-, and B-. As compared with more classical LBL of T-cell type, LBL of NK-cell type in our series occurred primarily in females and non-whites. Whereas treatment of classical LBL by multi-agent chemotherapy may lead to long-term survival, only two of our six patients were long-term survivors. The data derived from this study raise the possibility that LBL with the antigenic phenotype of NK cells may represent a biologic subtype of LBL.

Subclassification of follicular lymphomas by computerized microscopy.

The pilot feasibility study reported was carried out to determine whether computerized morphometry could be used to discriminate between different subtypes of follicular lymphomas. Thirteen cases of follicular lymphomas of the small cell and large cell types were examined by map-guided computerized microscopy. Initially, each specimen was digitized over a 5,120- X -5,120-microns area. Follicle maps depicting well-defined follicles were generated from these digitized images and used to guide a robot microscope to examine follicular center cells using from 20 to 100 fields, each 160 X 160 microns. Mathematical morphology was used to estimate the number of connected regions within each field examined. Based on the assumption that each connected region corresponded to a cell nucleus, it was expected that the number of connected regions found per unit area would correlate with the number of cells per unit area. Three prototypical small cell lymphomas and three prototypical large cell lymphomas were used as a training set to calibrate the methodology. Data obtained on these prototypical cases were used to establish statistical decision boundaries. Seven test cases, judged to be less typical but classifiable by experts, were then examined. Five of the seven were classified correctly, and the remaining two were identified as outliers. These results suggest that subclassification of follicular lymphomas may be aided by computerized microscopy. This pilot feasibility study is currently being expanded using a much larger sample of case material.

Immunoarchitecture of the "pseudofollicles" of well-differentiated (small) lymphocytic lymphoma: a comparison with true follicles.

Some human malignant lymphomas of the B-cell type have morphologic and immunologic similarities to follicles seen in nonneoplastic reactive lymph nodes. In contrast, a peculiar, vaguely nodular pattern of growth called "pseudonodules" or "pseudofollicular proliferation centers," which is morphologically distinguishable from "true" follicles, is seen in malignant lymphoma, well-differentiated (small) lymphocytic type (WDL). To characterize the cellular components of "pseudofollicles," we undertook a detailed, comparative immunohistologic study of the architectural relationship and distribution of T cells, B cells, and follicular dendritic reticulum cells (DRCs) in reactive follicles, neoplastic follicles, and pseudofollicles. We report several observations on the presence of DRCs and T-cell subset topography in pseudofollicles. Immunohistologic staining for the C3d complement receptor on DRCs revealed that DRC networks associated with "true" follicles were present in all cases of reactive follicular hyperplasia (RFH) and malignant lymphoma, nodular, poorly differentiated lymphocytic type (PDL) studied. Surprisingly, DRC networks were also identified in 8 of 23 cases of WDL. Although the size distribution of DRC network diameters was nearly identical in RFH and PDL, the sizes were markedly diminished in WDL. Immunohistologic staining for Leu 3+ and Leu 2+ T-cell subsets confirmed cellular arrangements in RFH and PDL reported by others. In only 2 of 23 cases of WDL could T cells localized to "pseudofollicles" in frozen tissue sections be identified in a nonrandom arrangement.

Marginal zone B-cell lymphomas: an appraisal.

Although the Revised European-American Lymphoma Classification does not utilize the term monocytoid B-cell Lymphoma, there are numerous reasons to support its use in classifying lymphomas of so-called marginal zone B-cell type that contain a distinct population of malignant monocytoid B-cells. In addition, there are other B-cell lymphomas which have very distinctive morphological features, because they show multiple and very well demarcated histologies characterized by presence of cells that appear to be (1) malignant monocytoid B-cells and malignant follicular center cells, or (2) malignant monocytoid B-cells, malignant follicular center cells and malignant plasma cells, or (3) malignant monocytoid B-cells and malignant mantle cells. The neoplastic cells in each of the above three examples show identical light chain restriction and thus they are part of the same neoplastic clone. We believe that there are different types of precursor B-cells (memory or otherwise) for the above cells, and an arrest in differentiation of these precursor B-cells may readily explain the presence of these different morphological combinations. Recognition of these morphological types may lead to further awareness of the possibilities of the existence of multiple, linked pathways of differentiation for lymphoid cells including the possibility of different types of precursor B-cells. Furthermore, an understanding of the uniqueness of monocytoid B-cells would allow pathologists to use terminology that is less redundant and more precise.

Multicentric angiofollicular lymph node hyperplasia: a clinicopathologic study of 16 cases.

A clinicopathologic analysis of 16 cases of multicentric angiofollicular lymph node hyperplasia (MAFH) was performed. Histologically, the disease was characterized by recognizable lymph node architecture that was at least partially intact, by paracortical hyperplasia with prominent vascular proliferation, and by numerous evenly distributed, apparently benign germinal centers of various types, usually including some typical hyaline-vascular centers. At the onset of the disease, 12 patients had the plasma cell (PC) type of MAFH, three patients had the hyaline-vascular (HV) type, and one patient presented with PC and HV types at separate sites. Transitions between the PC and HV types were observed in two cases. Immunologic studies demonstrated polyclonal populations of plasma cells in the lymph nodes of all patients and the absence of suppressor T lymphocytes in the one patient tested. Clinically, the patients had constitutional symptoms, multicentric lymphadenopathy, hepatosplenomegaly in many cases, and abnormal laboratory findings, including anemia, polyclonal hypergammaglobulinemia, and bone marrow plasmacytosis. The 16 patients were placed in four different clinical groups based on presentation and course: stable disease, chronic relapsing disease, aggressive disease, and development of malignant lymphoma. Ten of the 16 patients died (median survival, 26 months; range, eight to 170 months). Multicentric angiofollicular lymph node hyperplasia appears to be a variant of classic angiofollicular lymph node hyperplasia (Castleman's disease) and is associated with significant morbidity and mortality.

Epstein-Barr virus infections and Hodgkin's disease: a study of fixed tissues using the polymerase chain reaction.

Epstein-Barr viral (EBV) infections are associated with Hodgkin's disease (HD). To better characterize this relationship, fixed tissues of infectious mononucleosis, normal and reactive lymph nodes, lymph nodes with progressively transformed germinal centers, and biopsy specimens with the different subtypes of HD were analyzed by polymerase chain reaction (PCR). The presence or absence of EBV, the relative amounts of EBV, and the presence of multiple EBV genotypes as defined by amplification of a polymorphic EBV locus were determined for each specimen. Epstein-Barr virus could be detected from all specimens with infectious mononucleosis (eight of eight cases), generally in relatively large amounts, with multiple EBV genotypes evident in two cases. Epstein-Barr virus could not be detected from normal or reactive lymph nodes (none of 39 cases). Small amounts of EBV could be detected from a minority of cases with progressively transformed germinal centers (two of 16 cases), with multiple EBV genotypes evident in one case. Variable amounts of EBV could be detected from approximately half of the specimens with HD (26 of 50 cases). Epstein-Barr virus was most often detected in the subtypes of mixed cellularity (12 of 15 cases), nodular sclerosis (seven of 14 cases), and lymphocyte depletion (five of seven cases) compared with nodular lymphocyte predominance HD (two of 14 cases). In contrast to specimens with infectious mononucleosis and progressively transformed germinal centers, only one EBV genotype was evident in the specimens with HD. These findings are consistent with the hypothesis that some cases of HD may be directly associated with EBV.

Cytogenetic studies of composite lymphomas: monocytoid B-cell lymphoma and other B-cell non-Hodgkin's lymphomas.

Monocytoid B-cell lymphoma (MBCL) is a newly recognized, morphologically and immunologically distinct, low-grade B-cell neoplasm that may exist as a pure morphologic entity or as a component of a composite lymphoma. To determine whether cytogenetic abnormalities exist in cases of MBCL, fresh tissue from four lymphoma specimens in which MBCL was a substantial component were analyzed by classic cytogenetics; no pure MBCL cases were available for study. One monoclonal neoplastic population was found in each case by immunophenotyping studies and classic cytogenetics. Clonal cytogenetic abnormalities included -X or +X, t(14;18)(q32;q21), del(6q), t(11;14)(q13;q32), dup(12q), dup(1q), t(2;3)(q13;q29), and der(8)t(8;9)(p11.2;q13). The abnormal clone usually reflected the underlying lymphomatous process, namely, follicular lymphoma [t(14;18)], mantle cell lymphoma [t(11;14)], or small lymphocytic lymphoma (partial trisomy 12). There were no cytogenetic abnormalities common to all neoplasms. Taken together, the cytogenetic and immunologic data suggest that although MBCL may exist as a pure entity, it also may commonly represent a morphologic variant or a component of other primary lymphomatous processes.

Monoclonal small (well-differentiated) lymphocytic proliferations of the gastrointestinal tract resembling lymphoid hyperplasia: a neoplasm of uncertain malignant potential.

Three histologically benign-appearing or diagnostically equivocal small lymphocytic proliferations of the gastrointestinal tract were examined by fresh-frozen section immunohistologic techniques. In one case, a dense infiltrate in the small intestine, consisting of small lymphocytes with round nuclei, was limited almost entirely to the mucosa. In another case, a localized colonic polyp was formed by mucosal and submucosal lobules of benign-appearing lymphoid aggregates with centrally located germinal centers. The third case, a penetrating gastric ulcer, was surrounded by histologically hyperplastic lymphoid tissue which included germinal centers. The small lymphocytes in all three cases were strongly positive for B-cell-associated antigens (B1, B2, BA-1), and all exhibited monoclonal light-chain restriction. Even though treatment consisted only of surgical resection of the lesions, no patient has had progressive disease during follow-up periods ranging from 24 to more than 50 months. We believe that the infiltrates in these cases are analogous to the morphologically benign monoclonal small lymphocytic proliferations common to the lung and orbit and that they have an uncertain, but probably low, malignant potential.

Imprint cytology of non-Hodgkin's lymphomas based on a study of 212 immunologically characterized cases: correlation of touch imprints with tissue sections.

The classification of non-Hodgkin's lymphomas (NHLs) has been traditionally based on analysis of histologic sections and has been supplemented more recently by immunologic marker studies. It was the purpose of the present study to illustrate, side-by-side, sections and Romanowsky-stained imprints from the same surgical specimen from practically all categories of immunophenotyped NHLs, including rare and atypical variants that were difficult to classify from the histologic sections alone. Our results indicate that imprint cytology may reveal nuclear and cytoplasmic details not discernible in even the best tissue sections and that it may be selectively helpful in contributing to the classification of NHLs. Our results also show that the relative value of imprint cytology in the classification of malignant lymphomas varies greatly among categories. Specifically, we have found that imprints assist in three ways: the recognition of plasmacytoid features in small cell lymphocytic lymphomas, the recognition of plasmacytoid immunoblastic lymphoma, and the differentiation between NHLs which may be difficult to distinguish histologically. These include (1) small lymphocytic lymphoma versus lymphocytic lymphoma of intermediate differentiation, (2) true histiocytic malignancies versus large cell malignant lymphomas with abundant cytoplasm and/or phagocytosis, (3) anaplastic myeloma versus plasmacytoid immunoblastic lymphoma, (4) large noncleaved versus plasmacytoid immunoblastic lymphoma, (5) lymphoblastic lymphoma versus diffuse small cleaved cell lymphoma, and (6) lymphoblastic lymphoma versus small noncleaved cell lymphoma. Lymph node imprints are easy to prepare and readily interpretable by those experienced in the study of abnormal blood and bone marrow films. Their value as an ancillary methodology aimed at optimal accuracy in the classification of NHLs should be recognized.

Interfollicular small lymphocytic lymphoma: the diagnostic significance of pseudofollicles.

The pathologic, immunologic, and clinical features of 25 cases of interfollicular (IF) small lymphocytic lymphoma (SLL) characterized by pseudofollicles (PFs) in the IF region of the lymph nodes and by multiple reactive follicles (RFs) were examined. IFSLL is characterized morphologically by variable numbers and sizes of prolymphocytes (nuclei showing one centrally located prominent nucleolus) in the PFs and by small round lymphocytes in the IF region. The lymph nodes in our cases had multiple RFs (100%) and patent or partially patent sinuses (72%), with moderate expansion of the IF region (48%) and typically absent or minimal perinodal infiltration (48%). In 48% of the cases, the PFs surrounded the RFs, producing a pseudo-mantle zone pattern. Immunologic study showed the medium and large prolymphocytes to be mildly LN 1- and LN 2-positive, whereas the small prolymphocytes and lymphocytes were LN 1-negative and moderately LN 2-positive. Few cells in the IF region stained with UCHL-1 antibody. These data indicate the marked preponderance of the non-follicular center cell type of B cells in the IF areas. In all 11 cases tested, a monoclonal B cell population was found. The mean age of the patients was 62 years, with a male to female ratio of 1:1.7. B symptoms were present in 20% of the patients. Nineteen percent of the patients had clinical stage I or II disease, whereas 81% had stage IV disease. The median absolute lymphocyte count was 3,239 X 10(6), with a range of 767 to 13,770 X 10(6) cells/L. In six cases, the lymphocyte count was above 4,000 X 10(6), and in no case was it more than 15,000 X 10(6). It was difficult to distinguish these cases of IFSLL from lymphadenitis and other non-Hodgkin's lymphomas because it was difficult to recognize the subtle PF pattern in the presence of a partially preserved lymph node architecture. Because of the partially retained lymph node architecture and the expansion of the IF region by PFs, this lymphoma is thought to originate from the IF small B lymphocytes, which displayed an in situ growth pattern. Moreover, because of the predominant disease in the lymph nodes and the similarity of features in PFs and follicles, we conclude that IFSLL is a disease that is primary to the lymph nodes. IFSLL should be distinguished from mantle zone lymphoma and chronic lymphocytic leukemia.

Neoplastic B cells with cerebriform nuclei in follicular lymphomas.

Three cases of follicular lymphoma in which the follicular center cells exhibited pronounced nuclear irregularities, i.e., convoluted and cerebriform shapes, are described. The cytoplasm in B5-fixed sections was scanty to abundant and showed pale to clear staining, with interlocking cell borders. Although the architectural pattern in these cases suggested B-cell lymphoma, the cytologic features suggested a T-cell phenotype. Immunologic studies of frozen sections by immunohistochemical techniques in all three cases, as well as cell suspension studies in two cases, showed that the follicular center cells, including those with convoluted and cerebriform nuclei, were clearly monoclonal B cells, as evidenced by the presence of only one immunoglobulin light chain on the surfaces. The results of this study suggest that the follicular architectural pattern is a more reliable predictor of the immunologic phenotype than are the cytologic features.