Cost-effective approach to the diagnostic workup of B cell lymphoproliferative disorders via optimal integration of flow cytometric data

INTRODUCTION

The workup of lymphoproliferative disorders (LPDs) involves the combined use of flow cytometry (FC) and immunohistochemistry (IHC). This often results in duplicate immunophenotypic testing and adds costs that may not be eligible for reimbursement based on the Medicare National Correct Coding Initiative. We aimed to establish a cost-effective diagnostic algorithm based on initial FC categorization to reduce repetitive immunophenotyping.

METHODS

We retrospectively reviewed 242 cases of suspected LPDs with concurrent FC and IHC testing over a 12-month period. We correlated FC with surgical diagnoses and evaluated the frequency of repeat IHC testing.

RESULTS

Repetitive immunophenotyping was common; overall, 85% of cases had at least one marker repeated. Concordant cases were significantly less likely to have markers repeated than discordant cases. Of concordant B cell malignancies, 57% represented recurrent disease; however, repeat marker usage was not decreased as compared to new diagnoses. The most frequently repeated markers were CD3, CD5, CD10, and CD20.

CONCLUSIONS

We propose that in concordant cases, CD5 and CD10 should not be repeated by IHC; this would decrease the use of these markers by 80% and 76%, respectively. We developed an algorithmic approach to IHC usage that has improved incorporation of FC data at our institution and may reduce healthcare costs.

Plasma cells in muscle in inclusion body myositis and polymyositis

BACKGROUND

Previous immunohistochemical studies of muscle from patients with inclusion body myositis and polymyositis found many more T cells than B cells, suggesting a role for intramuscular cell-mediated immune mechanisms rather than humoral mechanisms.

METHODS

Microarray studies were performed on muscle biopsy specimens from 40 patients with inclusion body myositis (IBM; n = 23), polymyositis (PM; n = 6), and without neuromuscular disease (n = 11). Reverse transcription PCR of selected immunoglobulin gene transcripts was performed on two patient samples. Qualitative immunohistochemical studies for B-cell lineage cell surface markers were performed on 28 muscle specimens and quantitative studies performed on a subset of 19 untreated patients with IBM or PM. CD138+ cells were isolated from muscle using laser capture microdissection, and immunoglobulin transcripts were PCR amplified to determine the presence or absence of immunoglobulin gene rearrangements unique to the B-cell lineage.

RESULTS

Immunoglobulin gene transcripts accounted for 59% in IBM and 33% in PM of the most stringently defined highest differentially expressed muscle transcripts compared with normal. Plasma cells, terminally differentiated B cells expressing CD138 but not CD19 or CD20, are present in IBM and PM muscle in numbers several times higher than B cells.

CONCLUSIONS

There are differentiated B cells in the form of CD138+ plasma cells within the muscle of patients with inclusion body myositis and polymyositis. The principle of linked recognition of B-cell activation predicts several strategies for autoantigen discovery that could not otherwise be pursued through the study of the infiltrating T-cell population alone.

Inflammatory pseudotumor of lymph node and spleen: an entity biologically distinct from inflammatory myofibroblastic tumor

Inflammatory pseudotumors (IPTs) of the lymph node and spleen are an uncommon, benign cause of lymphadenopathy and/or splenomegaly that often bear striking clinicopathologic similarities to the inflammatory myofibroblastic tumors (IMTs) found in soft tissues. These tumors have classically been grouped together under the umbrella category of "inflammatory pseudotumor." Recent evidence shows that IMTs are in fact neoplastic processes that often harbor balanced chromosomal translocations involving the ALK kinase gene. These translocations result in expression of ALK kinase in IMTs as assessed by immunohistochemical studies. However, the relationship between IMT and IPT of the lymph node and spleen is uncertain. To determine if ALK tyrosine kinase expression is also present in IPT, 13 cases of IPT (9 involving lymph nodes, 4 splenic lesions) were examined for the presence of ALK tyrosine kinase by immunohistochemical staining on paraffin-embedded tissue. In addition, in situ hybridization studies for Epstein-Barr virus--encoded RNAs (EBER) and immunoperoxidase studies for human herpesvirus-8 (HHV8)--specific proteins were performed. All cases had clinical, morphologic, and immunophenotypic findings typical of IPT and had varying proportions of fibroblastic and inflammatory components. Age ranged from 11 to 75 (median, 40) years; 8 subjects were male, and 5 were female. None of the cases (0 of 13) had positive staining for ALK kinase or HHV8, and in 1 a lymph node (1 of 13) was focally positive for EBV (EBER) by in situ hybridization. The absence of ALK kinase as detected by immunohistochemical studies in IPT of the lymph node and spleen suggests that this entity is biologically distinct from the histologically similar IMT.

The value of thyroid transcription factor-1 in cytologic preparations as a marker for metastatic adenocarcinoma of lung origin

In tissue sections, thyroid transcription factor-1 (TTF-1) is a sensitive marker for adenocarcinomas of lung and thyroid origin. This immunohistochemical study evaluates the effectiveness of TTF-1 as a marker for pulmonary adenocarcinomas in paraffin sections of cell block preparations derived from effusion and fine-needle aspiration specimens. We evaluated 122 cell blocks including 8 primary and 39 metastatic pulmonary adenocarcinomas, 11 pulmonary neoplasms of other types, 50 specimens with nonpulmonary metastatic tumors, and 14 mesotheliomas. TTF-1 was reactive in 42 (89%) of 47 pulmonary adenocarcinomas. Only 1 of 4 pulmonary small cell/neuroendocrine tumors was TTF-1 positive, while 1 of 7 squamous cell carcinomas was weakly reactive. Of 50 metastatic tumors of nonpulmonary origin, focal weak reactivity was noted only for 1 metastatic ovarian carcinoma. All mesotheliomas were nonreactive. In cytologic preparations, TTF-1 is a highly selective marker for pulmonary adenocarcinoma and also can have a role in the distinction between pulmonary adenocarcinoma and mesothelioma.

Characterization of a murine high-affinity thiamine transporter, Slc19a2

Thiamine-responsive megaloblastic anemia with deafness and diabetes (TRMA) is a rare autosomal recessive disorder of thiamine transport. Previous studies have demonstrated that the disease is caused by mutations in the SLC19A2 gene encoding a high-affinity thiamine transporter. We hypothesize that thiamine transport, mediated by SLC19A2, plays a role in the development and or maintenance of several organ systems, in particular the erythropoietic, auditory, and glucose homeostasis systems. To investigate the transporter further, we cloned the murine Slc19a2 locus and characterized the resulting protein. Murine Slc19a2 is a 498 amino acid protein, with 12 predicted transmembrane domains. The gene spans approximately 13kb with 6 exons, structurally identical to that of the human homolog. We localized the Slc19a2 gene to mouse chromosome 1, a region syntenic to human chromosome 1q23 that contains the TRMA locus. Transient expression of Slc19a2 in HEK293T cells resulted in specific uptake of [3H] thiamine, confirming a thiamine transporter function. Western blot analysis of mouse tissues reveals a wide distribution of Slc19a2 protein. Immunohistochemistry studies indicate that Slc19a2 is expressed on the cell surface and intracellularly, and is specifically localized to a subpopulation of cells in cochlea, small intestine, and pancreas.

Altered apoptosis pathways in mantle cell lymphoma detected by oligonucleotide microarray

An imbalance between cellular apoptosis and survival may be critical for the pathogenesis of lymphoma. Therefore, the gene expression pattern in lymph node preparations from patients with mantle cell lymphoma (MCL) was compared to the pattern in nonmalignant hyperplastic lymph nodes (HLs). Oligonucleotide microarray analysis was performed comparing 5 MCLs to 4 HLs using high-density microarrays. The expression data were analyzed using Genespring software. For confirmation, the expression of selected genes was analyzed by real-time polymerase chain reaction using the RNA extracted from 16 MCL and 12 HL samples. The focus was on 42 genes that were at least 3-fold down-regulated in MCL; in addition to the B-cell leukemia 2 (BCL2) system other apoptotic pathways were altered in MCL. The FAS-associated via death domain (FADD) gene that acts downstream of the FAS cascade as a key gene to induce apoptosis was more than 10-fold down-regulated in MCL. Furthermore, the death-associated protein 6 (DAXX) gene, the caspase 2 (CASP2) gene, and the RIPK1 domain containing adapter with death domain (RAIDD) gene, which are key genes in other proapoptotic pathways, were also decreased in the MCL samples. The suggestion is made that in addition to the known overexpression of cyclin D1, which drives entry into the cell cycle, disturbances of pathways associated with apoptosis contribute to the development of MCL. (Blood. 2001;98:787-794)

TCL1 oncogene expression in B cell subsets from lymphoid hyperplasia and distinct classes of B cell lymphoma

Activation of the TCL1 oncogene has been implicated in T cell leukemias/lymphomas and recently was associated with AIDS diffuse large B cell lymphomas (AIDS-DLBCL). Also, in nonmalignant lymphoid tissues, antibody staining has shown that mantle zone B cells expressed abundant Tcl1 protein, whereas germinal center (GC; centrocytes and centroblasts) B cells showed markedly reduced expression. Here, we analyze isolated B cell subsets from hyperplastic tonsil to determine a more precise pattern of Tcl1 expression with development. We also examine multiple B cell lines and B lymphoma patient samples to determine whether different tumor classes retain or alter the developmental pattern of expression. We show that TCL1 expression is not affected by Epstein-Barr virus (EBV) infection and is high in naïve B cells, reduced in GC B cells, and absent in memory B cells and plasma cells. Human herpesvirus-8 infected primary effusion lymphomas (PEL) and multiple myelomas are uniformly TCL1 negative, whereas all other transformed B cell lines tested express moderate to abundant TCL1. This observation supports the hypothesis that PEL, like myeloma, usually arise from post-GC stages of B cell development. Tcl1 protein is also detected in most naïve/GC-derived B lymphoma patient samples (23 of 27 [85%] positive), whereas most post-GC-derived B lymphomas lack expression (10 of 41 [24%] positive). These data indicate that the pattern of Tcl1 expression is distinct between naïve/GC and post-GC-derived B lymphomas (P < 0.001) and that the developmental pattern of expression is largely retained. However, post-GC-derived AIDS-DLBCL express TCL1 at a frequency equivalent to naïve/GC-derived B lymphomas in immune-competent individuals (7 of 9 [78%] positive), suggesting that TCL1 down-regulation is adversely affected by severe immune system dysfunction. These findings demonstrate that TCL1 expression in B cell lymphoma usually reflects the stage of B cell development from which they derive, except in AIDS-related lymphomas.

Primary marginal zone lymphoma of the thymus

Primary low-grade B-cell lymphomas of the thymus are rare, with only 7 reported cases in the literature. We describe 3 cases of primary low-grade thymic lymphoma. All had histologic features of extranodal marginal zone lymphoma and were composed predominantly of small lymphocytes with variable components of monocytoid cells and plasma cells. Overt transformation to large cell lymphoma occurred in 1 case. The neoplastic cells were immunoreactive for the B-cell marker CD20 and were positive for bcl-2 in 2 cases. Two of 3 patients had a long-standing history of autoimmune disease. Based on these findings and those of previously reported cases, marginal zone lymphoma is the predominant type of low-grade thymic B-cell lymphoma. These tumors seem to be more common in patients with autoimmune disorders, and as observed with marginal zone lymphoma arising at other anatomic sites, they may undergo transformation to a higher grade lymphoma.

Kaposi's sarcoma-associated herpesvirus gene sequences are detectable at low copy number in primary amyloidosis

Primary amyloidosis (AL), like multiple myeloma (MM), results from a clonal proliferation of plasma cells. Recent detection of Kaposi's sarcoma-associated herpesvirus (KSHV) gene sequences in MM patients, although controversial, suggested that KSHV may also be present in AL. In the present study, we assayed for KSHV gene sequences in patients with primary AL independently in 2 laboratories. Nested polymerase chain reaction (PCR) was performed on DNA isolated from 21 bone marrow (BM) core biopsy samples to amplify orf26 and orf72, 2 regions of the KSHV genome. Eighteen of 21 (86%) BM core biopsy samples were KSHV PCR positive. BM aspirates from 16 of these 21 AL patients were cultured for 4-6 weeks to generate long term bone marrow stromal cells (LT-BMSCs), and 13 of 16 (81%) LT-BMSCs were also KSHV PCR positive. Results in all but 1 sample were consistent in the 2 laboratories. Sequencing of the PCR products in the 2 laboratories confirmed 94-98% and 95-98% homology to the published orf 26 and orf 72 KSHV gene sequences respectively, with interpatient base pair differences. Despite the presence of KSHV gene sequences, only 4/18 (22%) KSHV PCR positive patients demonstrated KSHV lytic antibodies by immunoblot assay. A sensitive assay performed on the BCBL-1 cell line confirmed the presence of KSHV at a very low copy number in AL. PCR using patient specific light chain gene primers also amplified DNA isolated from 2 AL BM core biopsies and 3 AL LT-BMSCs which were KSHV PCR positive, suggesting the presence of clonotypic cells. Our results therefore demonstrate KSHV gene sequences albeit at a very low copy number in the majority of BM core biopsies and LT-BMSCs from AL patients, and serological responses in only a minority of cases. Ongoing studies to identify viral transcripts and gene products will determine the biological relevance of KSHV in AL disease pathogenesis.

Positional cloning of zebrafish ferroportin1 identifies a conserved vertebrate iron exporter

Defects in iron absorption and utilization lead to iron deficiency and overload disorders. Adult mammals absorb iron through the duodenum, whereas embryos obtain iron through placental transport. Iron uptake from the intestinal lumen through the apical surface of polarized duodenal enterocytes is mediated by the divalent metal transporter, DMTi. A second transporter has been postulated to export iron across the basolateral surface to the circulation. Here we have used positional cloning to identify the gene responsible for the hypochromic anaemia of the zebrafish mutant weissherbst. The gene, ferroportin1, encodes a multiple-transmembrane domain protein, expressed in the yolk sac, that is a candidate for the elusive iron exporter. Zebrafish ferroportin1 is required for the transport of iron from maternally derived yolk stores to the circulation and functions as an iron exporter when expressed in Xenopus oocytes. Human Ferroportin1 is found at the basal surface of placental syncytiotrophoblasts, suggesting that it also transports iron from mother to embryo. Mammalian Ferroportin1 is expressed at the basolateral surface of duodenal enterocytes and could export cellular iron into the circulation. We propose that Ferroportin1 function may be perturbed in mammalian disorders of iron deficiency or overload.

Breakpoints of the t(11;18)(q21;q21) in mucosa-associated lymphoid tissue (MALT) lymphoma lie within or near the previously undescribed gene MALT1 in chromosome 18

Lymphomas arising in mucosa-associated lymphoid tissue (MALT) are indolent B-cell tumors that have a predilection for epithelial sites and often develop in a setting of chronic inflammation or autoimmunity. As many as 50% of low-grade MALT lymphomas contain an (11;18)(q21; q21) chromosomal translocation. Using fluorescence in situ hybridization, we have analyzed the position of recombination within chromosome 18 DNA in three examples of MALT lymphoma bearing this translocation. In all three cases, the breakpoint maps to DNA in BAC b357H2, covering about 150 kb of sequence. A previously undescribed, ubiquitously expressed gene, which we refer to as MALT1, was identified within this sequence and was found to be broken in one case for which we have definitively located the position of recombination between chromosomes 18 and 11. The sequence of this gene indicates the presence of two immunoglobulin-like C2 domains and a region of partial homology to caspases, suggesting a possible role for MALT1 in the regulation of apoptosis.

Crystal-storing histiocytosis: a disorder occurring in plasmacytic tumors expressing immunoglobulin kappa light chain

Intracellular immunoglobulin crystal formation within plasma cells is an uncommon finding in multiple myeloma and other lymphoplasmacytic tumors. We present 12 cases of plasmacytic tumors with prominent crystal formation, including myeloma (5 cases), lymphoplasmacytic lymphoma (6 cases), and a nonneoplastic plasma cell proliferation. In all cases, crystal formation was associated with the proliferation of variable numbers of histiocytes containing similar inclusions. These cases showed a variety of appearances, sometimes obscuring the underlying plasma cell tumor and raising the differential diagnosis of a storage disorder, hemophagocytosis, or a mesenchymal lesion. In cases of lymphoplasmacytic lymphoma, patients typically presented with marked paraproteinemia and symptoms of hyperviscosity. Crystal-storing histiocytosis was not associated with other immunoglobulin deposition disorders, including amyloidosis, Mott cell tumors, or kappa-light chain deposition. In our cases and those previously reported, we found an overwhelming association of crystal-storing histiocytosis (CSH) with tumors expressing immunoglobulin kappa light chain with no consistent association with a particular heavy chain. These results suggest that CSH results from the ingestion of crystals produced by plasma cell tumors that either overproduce kappa light chain or express a structurally aberrant molecule. CSH persists in the marrow and other sites throughout the course of the disease and in our series was not highly associated with development of the adult Fanconi syndrome or rapid clinical deterioration.

Relapse of acute myelogenous leukemia as a cerebellar myeloblastoma showing megakaryoblastic differentiation

Myeloblastomas (granulocytic sarcomas) occurring within the central nervous system (CNS) are extremely rare lesions that may develop in patients with acute or chronic myeloproliferative disorders. The majority of such lesions involve brain or spinal cord by contiguous spread from meningeal or bony sites, rather than originating within the CNS parenchyma. We describe a patient with acute myelogenous leukemia in remission, who developed a purely intraparenchymal cerebellar myeloblastoma with megakaryocytic differentiation. The neoplastic cells expressed the megakaryocytic markers factor VIII-related antigen and platelet glycoprotein-IIIa (CD61), and showed ultrastructural features that were indicative of megakaryocytic differentiation. Clinically, myeloblastomas of the CNS invoke a broad differential diagnosis that includes abscess, hemorrhage, and metastatic neoplasms because of their intraparenchymal location and radiologic features. Although they are rare, myeloblastomas should be included in the histopathologic differential diagnosis of a poorly differentiated neoplasm occurring within the CNS, particularly in a patient with a history of myeloproliferative or myelodysplastic disease.

Idiopathic pinealitis. Case report

This 63-year-old man presented with complaints of "having a feeling of falling backward" over a 3-month period. Results of his general physical examination, laboratory studies, and neurological examination were unremarkable. A magnetic resonance image revealed a 1.8 x 1.4 x 1.2-cm enhancing mass in the posterior third ventricle just above the corpora quadrigemina. The pineal gland was found to be diffusely enlarged at operation and separable from the posterior thalamus and was totally resected. The patient had an uneventful postoperative course but continues to be somewhat confused. The lesion consisted of a remarkable chronic inflammatory cell infiltrate permeating the pineal lobules and was composed of T and B lymphocytes, macrophages, eosinophils, and mast cells. Immunoperoxidase studies did not demonstrate Langerhans cells, and a search for microorganisms was unrevealing. There was no evidence of neoplasia; results of immunostaining for germ cell markers and other tumor-associated antigens were negative.

Detection of Kaposi's sarcoma herpesvirus DNA sequences in multiple myeloma bone marrow stromal cells

Whether Kaposi's sarcoma herpesvirus (KSHV) is associated with multiple myeloma (MM) remains controversial. We assayed for KSHV DNA sequences in long-term bone marrow stromal cells (BMSCs) from 26 patients with MM and 4 normal donors. Polymerase chain reaction (PCR) using primers which amplify a KSHV gene sequence to yield a 233-bp fragment (KS330233 within open reading frame 26) was negative in all cases. Aliquots of these PCR products were used as templates in subsequent nested PCR, with primers that amplify a 186-bp product internal to KS330233. BMSCs from 24 of 26 (92%) patients with MM and 1 of 4 normal donors were KSHV PCR+. DNA sequence analyses showed interpatient specific mutations (2 to 3 bp). Both Southern blot and sequence analyses confirmed the specificity of PCR results. The presence of the KSHV gene sequences was further confirmed by amplifying T 1.1 (open reading frame [ORF] K7) and viral cyclin D (ORF 72), two other domains within the KSHV genome. Immunohistochemical studies of KSHV PCR+ MM BMSCs demonstrate expression of dendritic cell (DC) lineage markers (CD68, CD83, and fascin). Serological studies for the presence of KSHV lytic or latent antibodies were performed using sera from 53 MM patients, 12 normal donors, and 5 human immunodeficiency virus (HIV)/KSHV+ patients. No lytic or latent antibodies were present in sera from either MM patients or normal donors. Taken together, these findings show that KSHV DNA sequences are detectable in BMSCs from the majority of MM patients, but that serologic responses to KSHV are not present. Ongoing studies are defining whether the lack of antibody response is caused by the absence of ongoing infection, the presence of a novel viral strain associated with MM, or underlying immunodeficiency in these patients.

Nodular lymphoid lesion of the liver: an immune-mediated disorder mimicking low-grade malignant lymphoma

Three cases of unusual lymphoid infiltrate forming nodular macroscopic masses in the liver were studied in the authors' surgical pathology laboratory. These lesions posed difficulty in diagnosis, and their differentiation from low-grade lymphoma was not possible on histopathologic evaluation alone. The liver masses were analyzed histologically and immunohistochemically as well as for clonal immunoglobulin heavy chain (IgH) and T-cell receptor gamma (TCR-gamma) gene rearrangements. The lesions were seen as solitary grossly distinct firm nodules in all three patients, measuring 0.4, 0.7, and 1.5 cm, respectively, in their greatest dimensions. Two were found in livers removed because of end-stage primary biliary cirrhosis at the time of orthotopic liver transplantation, and the third was an incidental finding during laparotomy. Microscopically, these were nodules composed of small lymphocytes, plasma cells, and immunoblasts, with varying degrees of admixed acute inflammatory cells and scattered lymphoid follicles. By immunohistochemistry and molecular studies, these were found to be reactive lymphoid proliferations. All patients are alive and well at 2, 4, and 13 years, respectively. It is concluded that these cases represent a unique type of nodular lymphoid lesion, which is probably an immune-mediated benign reactive hyperplasia. It constitutes an entity by itself and must be distinguished from low-grade lymphoma. For a definitive diagnosis, immunohistochemistry and molecular studies are required.

Epstein-Barr virus in Hodgkin's disease: correlation of risk factors and disease characteristics with molecular evidence of viral infection

Risk factors suggestive of relatively late exposure to EBV have been consistently associated with Hodgkin's disease (HD) in younger adults. In addition, evidence of EBV infection has been found in the Reed-Sternberg cells themselves in about one-third to one-half of all HD cases. However, no study yet published has correlated these childhood social environment risk factors with the presence of EBV in Hodgkin's tumor cells. We examined whether EBV-positive HD occurs in those patients whose childhood environment would predispose them to relatively late exposure to EBV. The study population consisted of 102 cases of mixed cellularity (MC; n = 25) or nodular sclerosing (n = 77) HD. Samples that tested positive for either EBV-encoded RNA or latent membrane protein or both were considered EBV-positive. Of the 102 cases, 83 completed a questionnaire regarding childhood social environment. The association with EBV-positivity was estimated by the odds ratio (OR) with 95% confidence intervals (CI). Twenty-two percent of the cases were EBV-positive. These cases were more likely to be MC (OR, 6.2; CI, 2.3-16.3) and male (OR, 3.4; CI, 1.3-9.0). History of infectious mononucleosis (IM) was not predictive of EBV-positivity, with only 3 of 14 such patients being EBV-positive (P = 0.82). Contrary to our hypothesis, no association between EBV and childhood environment risk factors was identified. The association of EBV with MC histology and male gender agrees with previous reports. The most intriguing finding was the dissociation between IM history and EBV-positivity, in that almost all of the cases with a history of IM were EBV-negative.

Development of gastrointestinal beta2-microglobulin amyloidosis correlates with time on dialysis

Dialysis-associated beta2-microglobulin (beta2m) amyloidosis affects predominantly musculoskeletal tissue, but visceral involvement also occurs. To evaluate the clinical significance and prevalence of gastrointestinal beta2m amyloidosis, we studied hemodialysis patients admitted for gastrointestinal-related complaints. Hemodialysis patients (excluding those with non-beta2m amyloidosis) who were admitted with gastrointestinal complaints from 1984 to 1994 were identified. Gastrointestinal tissues from patients with available autopsy or surgical specimens were examined using hematoxylin and eosin stain, Congo red stain, and beta2m immunostain. Each case was evaluated independently by two pathologists and scored for quantity and location of beta2m amyloid and associated pathology. Of 24 patients, eight (four men and 4 women) had beta2m amyloid deposits within the gastrointestinal tract. Acute clinical presentation ranged from abdominal pain to gastrointestinal bleeding and was not significantly different for patients with or without gastrointestinal beta2m amyloid deposits. However, the mean time on dialysis of 15.3 +/- 5.7 years (range 6-24 years) for patients with gastrointestinal beta2m amyloidosis was significantly greater than that of patients without gastrointestinal beta2m amyloidosis (10.5 +/- 7.0 years, range <1 to 22 years, p < 0.05). Vascular histopathology ranged from mild focal thickening of vessel walls to massive vascular beta2m amyloid deposition with thrombosis. Extravascular beta2m amyloid ranged from mild to severe with marked expansion of the submucosa. Mucosal pathology ranged from none to severe ulceration. The degree of beta2m amyloid and the associated pathology tended to increase in severity with time on dialysis. Gastrointestinal beta2m amyloid deposition is an underappreciated complication of chronic hemodialysis that is significantly associated with increased time on dialysis. Gastrointestinal beta2m amyloidosis should be considered in any patient on hemodialysis 10 years or more who has gastrointestinal symptoms and can be identified in resection specimens as well as some biopsy specimens. Congo red stain and beta2m immunostains may be necessary for sensitive histopathologic evaluation of gastrointestinal beta2m amyloidosis.

Alterations in fascin-expressing germinal center dendritic cells in neoplastic follicles of B-cell lymphomas

Germinal center dendritic cells (GCDCs) have essential functions in retention of immune complexes within secondary follicles, B-lymphocyte antigenic stimulation, B-cell activation, homing of B-cells via adhesion molecules such as ICAM-1 and VCAM-1, and B-cell survival via apoptosis. The neoplastic cells of follicular lymphomas (FLs) are thought to derive from follicular B lymphocytes, but their relationship to GCDCs remains unclear. This study used immunohistochemical staining for fascin, a 55-kDa actin-bundling protein strongly expressed in GCDCs and their processes, to evaluate their distribution in neoplastic follicles. Forty-two cases of B-cell FL were evaluated, and immunoreactive staining for fascin was compared with six cases of Castleman's disease (CD) and six cases of follicular hyperplasia. FLs generally revealed decreased or absent fascin-staining GCDCs, suggesting loss of fascin expression by dendritic cells in neoplastic follicles compared with hyperplastic follicular centers. In some follicles, there was partial retention of dendritic architecture with islands of residual syncytial network. Interdigitating reticulum cells in the parafollicular regions revealed normal fascin expression with intense staining of dendritic processes. In contrast with FLs, cases of follicular hyperplasia revealed normal or increased fascin-positive follicular dendritic cells, and in cases of hyaline vascular CD, follicular dendritic cells revealed tight syncytial networks. These results suggest that GCDCs are deficient in neoplastic follicles, compared with benign reactive or hyperplastic follicles. This alterations in the germinal center microenvironment might explain the inability of FL cells to present antigen to T lymphocytes and to mount an effective antitumor immune response.

In vivo expression of B7-1 and B7-2 by follicular lymphoma cells can prevent induction of T-cell anergy but is insufficient to induce significant T-cell proliferation

Expression of B7 family costimulatory molecules on B cells defines their capacity to function as antigen presenting cells (APCs). B cells that do not express B7 costimulatory molecules induce T-cell tolerance. Therefore, the expression of B7 costimulatory molecules on malignant B cells might be critical for their recognition by anti-tumor-specific T cells. Here we show that virtually all germinal center (GC)-derived B-cell lymphomas including follicular lymphoma (FL) and diffuse large cell lymphoma, but not mantle cell lymphoma or small lymphocytic lymphomas (SLL/CLL), express B7-1 (CD80) and B7-2 (CD86) on their cell surface in situ, although at extremely low levels. Despite their expression of low levels of B7-1 and B7-2, FL cells could not induce significant allogeneic T-cell proliferation. However, B7 costimulatory molecules on FL appeared to be functional because they were capable of increasing T-cell proliferation of preactivated T cells in a secondary allogeneic mixed lymphocyte response. Moreover, low B7 expression was sufficient to prevent the induction of alloantigen-specific anergy in vitro. Therefore, we postulate that whereas low-level expression of B7 is not sufficient to initiate a productive antilymphoma T-cell response, it might be sufficient to prevent T-cell tolerance in vivo.

The development of a model for the homing of multiple myeloma cells to human bone marrow

Prior in vitro studies have suggested a role of adhesion molecules, bone marrow stromal cells (BMSCs), and cytokines in the regulation of human multiple myeloma (MM) cell growth and survival. Although in vivo models have been developed in severe combined immunodeficient (SCID) mice that support the growth of human MM within the murine BM microenvironment, these xenograft models do not permit a study of the role of adhesion proteins in human MM cell-human BMSC interactions. We therefore established an in vivo model of human MM using SCID mice implanted with bilateral human fetal bone grafts (SCID-hu mice). For the initial tumor innoculum, human MM derived cell lines (1 x 10(4) or 5 x 10(4) ARH-77, OCI-My5, U-266, or RPMI-8226 cells) were injected directly into the BM cavity of the left bone implants in irradiated SCID-hu mice. MM cells engrafted and proliferated in the left human fetal bone implants within SCID-hu mice as early as 4 weeks after injection of as few as 1 x 10(4) MM cells. To determine whether homing of tumor cells occurred, animals were observed for up to 12 weeks after injection and killed to examine for tumor in the right bone implants. Of great interest, metastases to the right bone implants were observed at 12 weeks after the injection of 5 x 10(4) MM cells, without spread of human MM cells to murine BM. Human MM cells were identified on the basis of characteristic histology and monoclonal human Ig. Importantly, monoclonal human Ig and human interleukin-6 (IL-6), but not human IL-1beta or tumor necrosis factor-alpha, were detectable in sera of SCID-hu mice injected with MM cells. In addition, specific monoclonal Ig light chain deposition was evident within renal tubules. This in vivo model of human MM provides for the first time a means for identifying adhesion molecules that are responsible for specific homing of human MM cells to the human, as opposed to murine, BM microenvironment. Moreover, induction of human IL-6 suggests the possibility that regulation of MM cell growth by this cytokine might also be investigated using this in vivo model.

Umbilical cord 'pseudo-vasculitis' following second trimester fetal death: a clinicopathological and immunohistochemical study of 13 cases

Amniotic fluid bacterial infection is an occasional cause of second trimester septic abortion. We describe an autolysis-related histological artifact, umbilical cord 'pseudo-vasculitis', which can erroneously implicate amniotic bacterial infection in fetal death. Clinicopathological features of 13 second trimester fetal deaths with umbilical cord pseudo-vasculitis are reported. In four cases (31%), an incorrect pathological diagnosis of umbilical vasculitis had initially been rendered. Umbilical cords from five cases of pseudo-vasculitis and one comparison fetus (18-week septic abortion with true umbilical vasculitis), were studied with chloroacetate esterase and with immunohistochemical staining for myeloperoxidase, muscle-specific actin (HHF35) and smooth muscle actin. Histologically, umbilical pseudo-vasculitis exhibited numerous small, rounded, degenerating cells with irregular, multilobed nuclei (closely resembling neutrophils) located within the umbilical vessel wall. Immunohistochemical studies demonstrated that all cells resembling neutrophils were of smooth muscle origin. Moderate to severe fetal autolysis was present in all cases of umbilical pseudo-vasculitis, suggesting that this finding represents autolysis of umbilical vascular smooth muscle secondary to post moderate fetal retention. Vascular smooth muscle in other fetal and placental locations did not demonstrate the finding, suggesting that this striking degenerative artifact of smooth muscle is restricted to the umbilical cord.

The role of follicular and interdigitating dendritic cells in HIV-related lymphoid hyperplasia: localization of fascin

Fascin is a 55-kDa, actin-bundling protein expressed in follicular and interdigitating dendritic cells (DCs). Because these cells play a pivotal role in the pathogenesis of human immunodeficiency virus-related lymphoid hyperplasias (HLP), we evaluated them in 49 cases by immunohistochemical localization of fascin, and we related the findings to the histologic stage of disease. Fifteen cases of early HLP revealed strong localization of fascin within DCs of hyperplastic follicles and intense staining in interdigitating DCs and their processes in the interfollicular zones. Some follicles revealed focal disruption of the fascin-positive dendritic framework. DCs were also aligned beneath the peripheral sinuses of the node. In 15 cases of progressive HLP with partial follicular involution, 3 cases revealed findings similar to those described above. Twelve cases revealed loss of follicular dendritic staining, which was moderate in five cases and marked in seven. Residual clusters of DCs remained after partial dissolution. Interfollicular dendritic staining was reduced in 13 cases, and perisinusoidal staining was reduced in 7. In late-stage HLP, staining of both follicular and interdigitating DCs was reduced or absent. Nine cases of diffuse immunoblastic or angioimmunoblastic lymphadenopathy-like proliferation had markedly reduced or absent follicular DCs, but prominent staining was present in interfollicular DCs, which formed a meshwork throughout the node in eight cases. Two cases of hyaline-vascular lymphoid hyperplasia had increased follicular DCs forming a tight syncytial network. In most cases, there was reduction of dendritic fascin-expressing cells with advanced disease and destruction of the dendritic framework of the node. Diffuse hyperplasia of fascin-positive interdigitating cells occurred in cases with angioimmunoblastic morphologic features, and cases of hyaline-vascular lymphoid hyperplasia had increased follicular dendritic histiocytes forming a tight syncytial network. Destruction of DCs and, in some cases, interdigitating cell hyperplasia might be associated with the variable clinical course of HLP.

CD99 (p30/32MIC2) immunoreactivity in the diagnosis of leukemia cutis

The diagnosis of leukemia cutis and distinction of early myeloid cells and blasts from lymphoblasts or other lymphoid cells can be difficult, particularly if only fixed tissue is available. O13, a monoclonal antibody that recognizes CD99, the p30/32MIC2 gene product, has been used to identify a number of cell types, including lymphoblasts, in paraffin sections. To evaluate the usefulness of CD99 immunoreactivity in the diagnosis of leukemia cutis, we analyzed cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and acute myelogenous leukemia for the presence of this marker. Without the use of antigen retrieval methods, lymphoblasts in cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma were immunoreactive for CD99 in 9 of 9 cases. Myeloblasts and early myeloid cells in cases of cutaneous involvement by acute myelogenous leukemia were immunoreactive for CD99 in 12 (80%) of 15 cases. We conclude that CD99 is a sensitive but nonspecific marker for cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and that CD99 is immunoreactive in the vast majority of cases (21 [88%] of 24 cases) of leukemia cutis.

T-cell blast crisis in chronic myelogenous leukemia. Immunophenotypic and molecular biologic findings

T-cell blast crisis in chronic myelogenous leukemia is rare. We examined three patients (ages 35 to 72 years) in whom T-cell blast crisis developed 11 to 36 months (mean, 25 months) after diagnosis of chronic myelogenous leukemia and who died 4 to 12 months (mean, 7 months) thereafter. Two patients had diffuse lymphadenopathy, and the third had marked lymphocytosis (white blood cell count 217,000/microL, with 90% circulating blasts). In all three patients, neoplastic cells had the appearance of lymphoblasts and were immunoreactive for T-cell markers by immunohistochemical or flow cytometric analysis or both. Molecular diagnostic studies revealed the presence of a bcr-abl oncogene rearrangement in all three cases, but none exhibited a clonal T-cell receptor delta, beta, or gamma chain gene rearrangement. One case exhibited deletion of the J delta 1 region of both delta chain genes. The significance of these findings is discussed, and they are compared with those of other reported cases of T-cell blast crisis in chronic myelogenous leukemia.

Fascin, a sensitive new marker for Reed-Sternberg cells of hodgkin's disease. Evidence for a dendritic or B cell derivation?

Immunohistochemical localization of human fascin, a distinct 55-kd actin-bundling protein, was determined for a wide variety of lymphoid tissues (364 specimens total). In non-neoplastic tissues, reactivity was highly selective and localized predominantly in dendritic cells. In the thymus, this protein was distinctly localized to medullary dendritic cells. In reactive nodes, interdigitating reticulum cells of T zones, cells in subcapsular areas, and cells of the reticular network were reactive, with variable reactivity observed for follicular dendritic cells. Splenic dendritic cells of the white pulp and sinus-lining cells of the red pulp were reactive. Endothelial cells of all tissues exhibited variable reactivity. Lymphoid cells, myeloid cells, and plasma cells were uniformly nonreactive. In the peripheral blood, only dendritic (veiled) cells were reactive for fascin. A striking finding was observed for cases of Hodgkin's disease (total 187 cases). In all cases of nodular sclerosis (132), mixed cellularity (34), lymphocyte depletion (2), and unclassified types (5), all or nearly all Reed-Sternberg cells and variants were immunoreactive for fascin. Neoplastic cells exhibited strong diffuse cytoplasmic staining and frequently assumed dendritic shapes, particularly in the nodular sclerosis type, producing an interdigitating meshwork or syncytial network of cells. In cases of mixed cellularity type, neoplastic cells generally appeared more discrete. In all 14 cases of nodular lymphocyte predominance type, L&H variants were nonreactive. By contrast, neoplastic lymphoid cells of only 24 of 156 (15%) other lymphoid neoplasms (127 B cell, 27 T cell, and two null cell evaluated) were reactive for fascin. Fascin represents a highly effective marker for detection of certain dendritic cells in normal and neoplastic tissues, is an extremely consistent marker for Reed-Sternberg cells and variants of Hodgkin's disease (except L&H types), and may be helpful to distinguish between Hodgkin's disease and non-Hodgkin's lymphoma in difficult cases. The staining profile for fascin raises the possibility of a dendritic cell derivation, particularly an interdigitating reticulum cell, for the neoplastic cells of Hodgkin's disease, notably in nodular sclerosis type. However, as fascin expression may be induced by Epstein-Barr virus infection of B cells, the possibility that viral induction of fascin in lymphoid or other cell types must also be considered in Epstein-Barr virus-positive cases.

Cytologic diagnosis of primary serous lymphoma

Lymphomas arising primarily in serosal surfaces have recently been described. Although these "body-cavity" lymphomas usually present as an effusion, the role of cytologic diagnosis has not been fully explored. The authors present seven cases of primary serous lymphoma. All were large cell lymphomas (5 B cell types, 2 T cell types). Three distinct clinical presentations were seen. Four patients had the rapid onset of pleural effusions without an associated mass in the setting of immunodeficiency (3 with AIDS, 1 with Castleman's disease). Cytologic examination of the effusion was positive in all cases for B-cell lymphoma. All four patients died of their disease in less than 6 months. Two other patients with AIDS and T-cell lymphomas both of which were associated with a serosal mass as well as an effusion. Although cytologic examination revealed numerous atypical lymphoid cells, clonality could not be demonstrated. One patient survived for more than 1 year, the other lymphoma was an incidental finding at autopsy. Finally, one B-cell lymphoma arose in a patient with chronic pleuritis. Pleural decortication was required to identify the neoplastic cells. The authors conclude that primary serosal lymphomas have characteristic clinical presentations, and that although cytologic and flow cytometric examination of effusions is necessary for the diagnosis of immunodeficiency associated B-cell lymphomas, tissue biopsy will likely be required in patients with immunodeficiency-associated T-cell lymphomas or lymphomas associated with chronic pleuritis.

Circulating human dendritic cells differentially express high levels of a 55-kd actin-bundling protein

This study was initiated to examine the differential expression of an evolutionary conserved human 55-kd actin-bundling (p55) protein that is induced in B lymphocytes by Epstein-Barr virus infection. Our study demonstrates that p55 is specifically expressed at constitutively high levels in human peripheral blood dendritic cells and lymph node (interdigitating) dendritic cells. Blood dendritic cells constitute a minority (< 2%) of all blood leukocytes but are a distinct population of potent antigen-presenting cells. Immunofluorescence microscopy with a monoclonal antibody specific for p55 showed that 87% of peripheral blood dendritic cells stained brightly in the cytoplasm and in the veiled cytoplasmic extensions. In contrast, monocytes, granulocytes, T cells, and B lymphocytes showed no expression of the p55 protein. Western blot analysis confirmed that only the dendritic cell component of peripheral blood expressed high levels of p55. Staining of human lymph node sections demonstrated selective expression of the p55 antigen by dendritic cells in the T-cell-dependent areas but not in the B cell follicles. p55 is likely to be involved in the organization of a specialized microfilament cytoskeleton in the dendritic cells, and the anti-p55 antibody should be useful for further characterization of this important population of antigen-presenting cells in clinical transplantation, HIV-1 pathogenesis, and autoimmune diseases.

Follicular lymphomas can be induced to present alloantigen efficiently: a conceptual model to improve their tumor immunogenicity

In the tumor-bearing host, T cells invariably fail to induce a clinically significant antitumor immune response. Although model systems support the existence of tumor peptide antigens, the molecular interactions critical for antigen presentation by the tumor cell remain unresolved. Here, we demonstrate that human follicular lymphoma cells are highly inefficient at presenting alloantigen despite their strong expression of major histocompatibility complex and low-to-intermediate expression of some adhesion and B7 costimulatory molecules. Activation of follicular lymphoma cells via CD40 induces or up-regulates both adhesion and B7 costimulatory molecules essential to repair this defect. More importantly, once primed, alloreactive T cells efficiently recognize unstimulated follicular lymphoma cells. Thus, correction of defective tumor immunity requires not only expression of major histocompatibility complex but also sufficient expression of multiple adhesion and costimulatory molecules.

Synovial tissue response to treatment with Campath-1H

OBJECTIVE

Therapeutic trials in rheumatoid arthritis with the monoclonal antibody Campath-1H have demonstrated recurrent clinical synovitis in some patients, despite profound depletion of circulating lymphocytes. This study was undertaken to examine the cellular infiltrates in synovial tissue at a time of persistent peripheral lymphopenia.

METHODS

Immunohistochemical staining of synovial tissue and peripheral blood lymphocyte phenotyping.

RESULTS

Synovial tissues from 2 patients with recurrent synovitis after Campath-1H therapy contained significant T lymphocytic infiltrates at a time when circulating T lymphocytes were markedly depleted.

CONCLUSION

These results demonstrate that peripheral blood analysis may not accurately reflect the synovial tissue response to monoclonal antibody therapy.

Bcl-2 oncogene protein is preferentially expressed in Reed-Sternberg cells in Hodgkin's disease of the nodular sclerosis subtype

One hundred three cases of nodular sclerosis (NS) and mixed-cellularity Hodgkin's disease were evaluated for expression of bcl-2 oncogene protein, because previous studies have revealed expression of bcl-2 in these subtypes but only rarely in the nodular lymphocyte-predominance subtype. Reed-Sternberg (RS) cells and lacunar variants were positive for bcl-2 in 51 of 86 NS cases and 4 of 17 mixed-cellularity cases. In individual cases of NS, the percentage of RS cells and lacunar variants positive for bcl-2 ranged from minimal (in 5 cases) to 100% positive (mean, 34%). By univariate analysis, expression of the bcl-2 gene product in RS cells was observed in a significantly greater proportion of NS Hodgkin's disease cases than MC cases (P < .009), a finding that may have implications on the pathogenesis of this disorder.

Immunohistochemical detection of Epstein-Barr virus-encoded latent membrane protein in Reed-Sternberg cells and variants of Hodgkin's disease

A total of 186 specimens of Hodgkin's disease of various histologic types (127 nodular sclerosis, 39 mixed cellularity, 14 lymphocyte predominance, 3 lymphocyte depleted, and 3 unclassified) were evaluated for the presence of latent membrane protein (LMP) and Epstein-Barr virus nuclear antigen-2, two Epstein-Barr virus encoded gene products that appear to play important roles in cell transformation and oncogenesis. Immunoreactivity for LMP was observed in Reed-Sternberg cells and variants of 27/39 (69%) cases of mixed cellularity type, 18/127 (14%) of nodular sclerosis type, 2/3 cases of lymphocyte depleted type, and 1/3 cases of unclassified type. All cases of lymphocyte predominance Hodgkin's disease were nonreactive for LMP. In cases that were reactive for LMP, staining was restricted to Reed-Sternberg cells and variants. Other cells within the proliferation, e.g., lymphocytes, histiocytes, eosinophils, fibroblasts, etc., were nonreactive. The pattern of immunoreactivity for LMP was characterized by strong diffuse cytoplasmic staining, occasionally with membrane accentuation and/or paranuclear staining. Reactivity for LMP was demonstrated in cryostat sections and was also well preserved in paraffin sections of B5- or formalin-fixed tissues. Five of six specimens of Hodgkin's disease (4 mixed cellularity and 2 nodular sclerosis type) that occurred in HIV-positive patients exhibited immunoreactivity for LMP in Reed-Sternberg cells and variants. Cryostat section studies for Epstein-Barr virus nuclear antigen-2 using monoclonal antibody PE-2 failed to reveal staining for 43 cases (26 nodular sclerosis, 12 mixed cellularity, and 5 lymphocyte predominance) after a 2-h incubation with primary antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Distinction between small lymphocytic and mantle cell lymphoma by immunoreactivity for CD23

Immunoreactivity for CD23, a B-cell activation antigen, was compared in 22 cases of B-cell small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and 15 cases of mantle cell lymphoma (MCL) (intermediate lymphocytic lymphoma or centrocytic lymphoma) to determine if the presence of this antigen can be used as a criterion to distinguish between these two low-grade B-cell lymphoproliferative processes. CD23 immunoreactivity was observed in 21 of 22 cases (95%) of SLL/CLL, whereas only 2 of 15 cases (13%) of MCL were reactive for this antigen; therefore, lack of CD23 reactivity is statistically significantly associated with MCL (P < 0.0001). In addition, lack of CD23 immunoreactivity is also statistically significantly associated with SLL with plasmacytoid differentiation in comparison with typical SLL (P < 0.0003), although only a small number of cases were evaluated. SLL/CLL, MCL, and SLL with plasmacytoid differentiation cases were all uniformly immunoreactive for pan-B-cell antigens such as CD20 and CD22. Immunoreactivity for CD23 appears to be a useful marker to aid in distinguishing SLL/CLL from MCL and may be helpful in routine immunophenotypic screening of low-grade B-cell derived lymphoproliferative processes.

Accelerated healing of duodenal ulcers by oral administration of a mutein of basic fibroblast growth factor in rats

BACKGROUND/AIMS

Human basic fibroblast growth factor (bFGF) is an endothelial mitogen that stimulates angiogenesis and proliferation of other cells such as fibroblasts and smooth muscle cells. After this peptide was stabilized to acid and pepsin by site-specific mutagenesis, it was tested whether bFGF might accelerate the healing of experimental duodenal ulcers.

METHODS

This mutein peptide (bFGF-CS23) was administered orally in comparison with cimetidine to rats with chronic duodenal ulcers previously induced by cysteamine.

RESULTS

Oral bFGF-CS23 therapy maintained for 21 days at 100 ng/100 g twice daily resulted in (1) significant acceleration of healing of duodenal ulcers, i.e., reduction of mean ulcer area by 83% in the bFGF-CS23-treated rats compared with only 61% for cimetidine therapy and 40% for untreated controls; (2) complete healing with no residual ulcer in 62% of the bFGF-CS23-treated rats compared with only 7% of untreated rats; and (3) a ninefold increase in angiogenesis in the ulcer bed compared with untreated controls. A single dose of the bFGF-CS23 mutein had no effect on gastric output of hydrochloric acid or pepsin, but daily treatment for 2 or 3 weeks resulted in enhanced acid and pepsin outputs.

CONCLUSIONS

Chronic duodenal ulcers can be healed rapidly by stimulating angiogenesis and other wound-healing processes in the ulcer bed without reduction of gastric acid.

Small lymphocytic non-Hodgkin's lymphoma of suppressor/cytotoxic T-cell phenotype [CD4(-), CD8(+)]

An unusual case of small lymphocytic non-Hodgkin's lymphoma of suppressor/cytotoxic T-cell phenotype is described. The patient presented with significant involvement of the spleen, lymph nodes, and bone marrow, but without a leukemic phase. Most small lymphocytic lymphomas are of B-cell phenotype, and those of T-cell origin are overwhelmingly of T-helper/inducer phenotype. Furthermore, T-cell lymphoproliferative lesions of suppressor/cytotoxic phenotype generally present as leukemias comprising large granular lymphocytes. This case reveals that suppressor/cytotoxic T lymphocytes may give rise to a lymphoproliferative disorder with a distinctive phenotype and presentation.

Lineage-restricted chromosome translocation in a benign fibrous tumor of the breast

We describe a clonal chromosome rearrangement, t(4;14)(q24-25;q24.3), in a benign fibrous tumor of the breast. This is the first reported cytogenetic analysis of a fibrous tumor of the breast and the first evidence for clonality in these lesions. A combined immunohistochemical/cytogenetic study demonstrated that cells with the clonal translocation were mesenchymal. Epithelial cells, in contrast, had normal chromosomes.

Intermediate lymphocytic lymphoma: clinical and pathologic features of a recently characterized subtype of non-Hodgkin's lymphoma

PURPOSE

We present a comprehensive review of clinical, pathologic, molecular, and prognostic features and therapy of intermediate lymphocytic (mantle cell) lymphoma (ILL/MCL), a recently characterized subtype that represents 2% to 8% of non-Hodgkin's lymphomas (NHLs), but which has not been included in most classification schemes, including the International Working Formulation.

DESIGN

The English-language literature encompassing the above aspects, published between 1977 and 1992, is critically reviewed.

RESULTS AND CONCLUSION

ILL/MCL is a disease of proliferating B lymphocytes that is characterized by generalized lymphadenopathy and frequent, often extensive, involvement of the spleen, bone marrow, and gastrointestinal tract. The malignant cells usually express the markers CD5 and IgM with or without IgD, but not CD10, on the cell surface, and grow in one of two dominant histologic patterns: mantle zone and diffuse. The characteristic cytogenetic abnormality is a t(11;14)(q13;q32) translocation, which juxtaposes the bcl-1 locus on chromosome 11 with the immunoglobulin (Ig) heavy-chain locus on chromosome 14, and appears to result in dysregulated expression of the gene encoding cyclin D1. Median survival is in the range of 2 to 5 years. While responses to chemotherapy may be seen in up to half the patients, relapses are the rule, and longterm survival is uncommon. The optimal treatment remains undefined, although therapy may be deferred until there are symptoms or complications, at which time judicious administration of alkylating agents and glucocorticoids may result in effective palliation.

Clonal rearrangement of chromosome band 6p21 in the mesenchymal component of pulmonary chondroid hamartoma

Pulmonary chondroid hamartomas (PCH) are biphasic benign tumors that contain both mesenchymal and epithelial populations. In this report we describe two PCH in which clonal translocations at chromosome band 6p21 were demonstrated in mesenchymal cells. One of these had a unique translocation, t(6;14)(p21;q24), that was also found in one of two PCH karyotyped previously. The t(6;14) has not been described in other varieties of benign or malignant neoplasia. The 6p21 aberrations are of particular interest because break points in this chromosomal region appear to be characteristic of endometrial polyps. Endometrial polyps, like PCH, are biphasic benign tumors in which mesenchymal clonality has been demonstrated.

Clonal 6p21 rearrangement is restricted to the mesenchymal component of an endometrial polyp

Previous cytogenetic analyses revealed t(6;20)(p21;q13) in two endometrial polyps. We karyotyped a large endometrial polyp in which 19 of 25 metaphase cells contained a t(1;6;4)(q21;p21;q13). Subsequent combined immunohistochemical/cytogenetic analysis showed all aberrant metaphase cells to be of mesenchymal derivation, whereas epithelial cells from the polyp were diploid. These studies indicate that rearrangement of chromosome band 6p21 is a characteristic cytogenetic aberration in the stromal component of endometrial polyps.

Utility of high-resolution ultrasound for the diagnosis of dialysis-related amyloidosis

OBJECTIVE

To evaluate the utility of real-time, high-resolution ultrasound of the shoulder in the diagnosis of dialysis-related amyloidosis.

METHODS

We performed a case series study of 2 groups of patients seen at a referral-based clinic in a tertiary care hospital. The shoulders of 13 patients with normal renal function and of 38 patients receiving long-term hemodialysis were studied by real-time, high-resolution ultrasound. All hemodialysis patients were evaluated clinically for the presence of dialysis-related amyloidosis. Surgical specimens of joints were available for all 13 patients with normal renal function and for 17 of the 38 hemodialysis patients. These specimens were evaluated for the presence of beta 2-microglobulin (beta 2m) amyloid by Congo red and immunohistochemical staining.

RESULTS

Two ultrasonographic findings were selectively observed in the dialysis patients with clinical and histologic evidence of beta 2m amyloid in comparison with patients with normal renal function and no evidence of amyloid: rotator cuffs greater than 8 mm in thickness and echogenic pads between muscle groups of the rotator cuff. The presence of at least 1 of these 2 findings corresponded to the presence of clinically and histologically evident beta 2m amyloid with a sensitivity of 79% and a specificity of 100%. When additional patients without surgical specimens for histologic confirmation of amyloidosis were included, the sensitivity of these 2 sonographic findings was 72% and the specificity was 97%.

CONCLUSION

Real-time, high-resolution ultrasound is a relatively sensitive and highly specific noninvasive adjunct to the clinical diagnosis of beta 2m amyloidosis in patients receiving long-term hemodialysis.

A histiocyte-specific marker in the diagnosis of malignant fibrous histiocytoma. Use of monoclonal antibody KP-1 (CD68)

KP-1 (CD68) is a recently described monoclonal antibody to a cytoplasmic epitope present on tissue histiocytes and macrophages. To determine the specificity and sensitivity of this marker in the evaluation of cases of malignant fibrous histiocytoma (MFH), this reagent and a panel of commercially antibodies were used to stain formalin-fixed paraffin sections from 25 cases of MFH and 25 other tumors, including a variety of soft-tissue sarcomas. Eighteen of 25 cases of MFH stained for KP-1 (72%), whereas all other tumors were negative, including 12 cases of pleomorphic soft-tissue sarcoma other than MFH. The percentage of tumor cells staining for KP-1 varied. In 11 cases KP-1 was only focally present, but staining was of a high intensity and associated with minimal nonspecific or background staining. Pleomorphic histiocytic cells and spindle cells from storiform tumors were strongly decorated with antibodies to KP-1 in most cases, and antigen also was present on tumor giant cells. Although alpha-1-antitrypsin and alpha-1-chymotrypsin stained a higher percentage of cases of MFH (92%), immunoreactivity for these markers also was noted in other tumors. Because of its specificity as a histiocyte marker, KP-1 is a useful component in a panel of antibodies for the characterization of soft-tissue sarcomas and the diagnosis of MFH.

All advanced stage non-Hodgkin's lymphomas with a polymerase chain reaction amplifiable breakpoint of bcl-2 have residual cells containing the bcl-2 rearrangement at evaluation and after treatment

Polymerase chain reaction (PCR) of bcl-2 provides an extremely sensitive method to detect minimal disease in approximately 50% of patients with non-Hodgkin's lymphomas (NHL). In an attempt to determine the clinical usefulness of this technique, we examined the bone marrow (BM) of 152 patients with advanced-stage NHL at the time of evaluation and after induction or salvage chemotherapy before autologous BM transplantation. The BM proved to be an accessible and reproducible tissue source to determine PCR positivity because all of the 102 patients examined had the same PCR-amplifiable breakpoint in their BM and lymph node. At the time of evaluation, PCR analysis in advanced-stage NHL patients added little additional information to morphologic analysis because each technique identified BM infiltration in approximately 70% of patients. PCR was significantly more useful in determining BM infiltration after induction or salvage therapy. At that time, approximately 50% of patients had morphologically normal BM, whereas PCR analysis remained positive in 100% of those with an amplifiable breakpoint. These observations were confirmed in a clinical trial attempting to induce remission in previously untreated low-grade advanced-stage NHL patients. In this series, PCR was positive in all patients after treatment although the BM was histologically uninvolved in 50% of cases, showing that conventional therapy did not eradicate bcl-2-positive cells.

Myeloperoxidase: a specific marker for myeloid cells in paraffin sections

Immunohistochemical detection of intracellular myeloperoxidase, a major constituent of primary granules of neutrophilic myeloid cells, was determined in paraffin sections of 161 specimens using a rabbit polyclonal antibody to human myeloperoxidase and an indirect immunoperoxidase technique. In normal tissues and in a variety of myeloproliferative disorders, myeloid cells of both neutrophilic and eosinophilic types, at all stages of maturation, exhibited strong cytoplasmic reactivity for myeloperoxidase. Myeloperoxidase was readily detected in myeloblasts and immature myeloid cells of acute myelogenous leukemia, progranulocytic leukemia, monomyelocytic leukemia, erythroleukemia, myeloblastomas, and other hematopoietic disorders. Erythroid precursors, megakaryocytes. other hematopoietic disorders. Erythroid precursors, megakaryocytes, lymphoid cells, mast cells, and plasma cells were nonreactive. Cells of monocytic derivation revealed variable reactivity and were typically weakly positive or nonreactive. In a few specimens, rare histiocytes were reactive, some possibly due to phagocytosed material. Cells comprising the infiltrate of a spectrum of lymphoid malignancies, e.q., lymphoblastic lymphoma or leukemia, chronic lymphocytic leukemia, hairy cell leukemia, non-Hodgkin's lymphomas of T- or B-cell type, and Hodgkin's disease, were nonreactive, as were the non-neoplastic tissues present in these specimens, except for occasional cells of myeloid derivation. Myeloperoxidase was not observed in the neoplastic cells of a wide variety of epithelial tumors and sarcomas, or in the contiguous non-neoplastic tissues. Immunoreactivity for myeloperoxidase was well preserved following fixation in a variety of fixatives, including Zenker's-acetic acid solution (employed for processing bone marrow biopsies), B5 solution, and formalin. Immunohistochemical detection of myeloperoxidase represents a sensitive and highly specific technique for identification of mature and immature myeloid cells in paraffin-embedded tissue.

Ki-1-positive large cell lymphomas, a heterogenous group of neoplasms. Morphologic, immunophenotypic, genotypic, and clinical features of 24 cases

Clinical and pathologic features of 24 patients with large cell lymphomas that expressed the activation antigen Ki-1 are described. Phenotypic and/or genotypic studies characterized these neoplasms as T-cell (16 cases), B-cell (six cases), or null cell (two cases) type. Males predominantly were affected. Age of patients ranged from 19 to 73 years, with a bimodal distribution, with peaks in the third and seventh decades. Lymphadenopathy was present in nearly all patients. Extranodal involvement, including skin, soft tissue, bone, central nervous system, lung, or small intestine was observed in a total of 54% of the patients, either at presentation or during the course of disease. "Prototypic" features of large cell anaplastic lymphomas were observed for eight T-cell lymphomas, with morphologic heterogeneity noted for the remainder. Eight patients, all with T-cell neoplasms (only one with prototypic morphology), have died of lymphoma (median survival, 5 months). An antecedent history of a lymphoproliferative disorder (mycosis fungoides, B-cell lymphoma, immunoblastic lymphadenopathy) was apparent in seven patients. An 8-year history of Crohn's disease occurred in one patient with a T-cell lymphoma involving small intestine. Phenotypically, loss of one or more markers was typically noted for T-cell neoplasms. Leukocyte common antigen was detected in all cases, although partial loss of immunoreactivity was noticed in some cases. Nearly all cases evaluated for Ia antigen or alpha-1-antichymotrysin were reactive. Eleven of 16 T-cell, two of six B-cell, and two null cell lymphomas expressed epithelial membrane antigen. Ki-1-positive large cell lymphomas are characterized by clinical, morphologic, and immunophenotypic heterogeneity.

Hodgkin's disease presenting as an enlarged thyroid gland. Report of a case diagnosed by fine needle aspiration

An unusual case of Hodgkin's disease (HD) in a 36-year-old woman that was diagnosed by fine needle aspiration (FNA) biopsy of a neck mass believed clinically to be diffuse goiter is reported. The aspirate was composed mainly of dispersed lymphocytes; admixed with these were occasional large mononuclear cells with round-to-oval nuclei and prominent nucleoli. Binucleated variants of the large cells were interpreted as Reed-Sternberg cells, suggesting the diagnosis of HD. Subsequent to the FNA biopsy, radiologic examinations demonstrated an enlarged mediastinum, and incisional biopsy of the neck mass confirmed the diagnosis of HD. This case emphasizes the value of FNA biopsy as a rapid and reliable procedure, even in the unusual but established clinical presentation of HD as a diffuse neck mass.

Lineage-restricted clonality in biphasic solid tumors

Cytogenetic analysis of two pulmonary chondroid hamartomas and nine breast adenofibromas revealed clonal chromosome aberrations in both hamartomas and in four breast tumors. To determine lineage of the cells with chromosome aberrations, a combined immunohistochemical/cytogenetic approach was developed that enabled simultaneous ascertainment of cytogenetic aberrations and immunohistochemical features in individual cells. Immunohistochemical/cytogenetic evaluation of one hamartoma and two adenofibromas demonstrated that neoplastic proliferation, in each case, was confined to the mesenchymal (stromal) component, whereas epithelial cells appeared to be reactive. Cytogenetically abnormal short-term cultures of the remaining hamartoma and another of the breast adenofibromas were composed entirely of mesenchymal elements, indicating mesenchymal clonality in those tumors as well. Our findings support redesignation of pulmonary chondroid hamartomas as 'pulmonary chondromas' and suggest that carcinomas developing within fibroadenomas arise from reactive epithelial proliferation. Combined immunohistochemical/cytogenetic analysis might be useful in the development of novel therapeutic approaches that selectively target neoplastic populations within solid tumors.

Diagnostic relevance of clonal cytogenetic aberrations in malignant soft-tissue tumors

BACKGROUND

Malignant soft-tissue tumors often present substantial diagnostic challenges. Chromosome aberrations that might be diagnostic have been identified in some types of soft-tissue tumors, but the overall frequency and diagnostic relevance of these aberrations have not been established.

METHODS

We attempted to determine the karyotypes of a series of 62 consecutive, unselected malignant spindle-cell or small round-cell soft-tissue tumors (from 46 adults and 16 children) after direct harvesting of cells or short-term culture. All tumors were examined independently by immunohistochemical staining in addition to routine light-microscopical evaluation, and all but two tumors were examined by electron microscopy.

RESULTS

Metaphases were obtained from 61 of the 62 tumors, and clonal chromosome aberrations were identified in 55 (89 percent). In the six tumors that yielded metaphases but lacked apparent clonal aberrations, the normal metaphases were found to originate from non-neoplastic stromal elements within the tumor specimens. Thus, all tumors in which karyotyping was successful contained clonal chromosome aberrations. Forty of 62 tumors (65 percent) contained clonal chromosome aberrations that either suggested or confirmed a specific diagnosis; in 15 of these tumors (24 percent of all tumors), the aberrations were important in establishing the final diagnosis. Cytogenetic analyses were particularly informative about small round-cell tumors from children: 8 of 14 round-cell tumors contained diagnostically important chromosome aberrations. Using the combined approaches of light and electron microscopy, immunohistochemistry, and cytogenetics, we established an unambiguous diagnosis for 60 of 62 tumors.

CONCLUSIONS

Cytogenetic analyses reveal clonal chromosome aberrations in virtually all malignant soft-tissue tumors. These clonal chromosome aberrations, particularly in small round-cell tumors in children, often have diagnostic relevance.