Persistent lymphadenopathies in people at high risk for HIV infection. Clinicopathologic correlations and long-term follow-up in 79 cases

Reactive Lymphoid Hyperplasia with Giant Follicles Associated with a Posttherapeutic State of Hematological Malignancies. A Report of Eight Cases

Aims and background

To further clarify the clinicopathological, molecular genetic and karyotypic findings of reactive lymph node hyperplasia with giant follicles (RLHGF) associated with a posttherapeutic state of hematological malignancies, we studied eight such cases.

Methods

Using formalin-fixed, paraffin-embedded sections, histological, immunohistochemical, in situ hybridization (ISH), and polymerase chain reaction (PCR) were performed.

Results

Six patients had a history of malignant lymphoma (diffuse large B-cell lymphoma [DLBCL] = 4, marginal zone B-cell lymphoma = 2), and two had acute myeloid leukemia (AML). Six patients initially presented with lymphadenopathy of the head and neck area and the remaining one presented with swelling of the tonsil. All seven cases demonstrating analyzable metaphases showed a normal karyotype. Histologically, all eight lesions were characterized by numerous enlarged, bizarre-shaped coalescing lymphoid follicles with follicular lysis. Immunohistochemical and flow cytometry study demonstrated the reactive nature of the B cells in all eight lesions. However, three of our eight cases demonstrated immunoglobulin heavy-chain (IgH) gene rearrangement on PCR study. Different clonal bands were detected in the initial lymphomatous tissue and RLHGF in one of the studied cases. There was no development of B-cell lymphoma or recurrence of B-cell lymphoma in any of the three lesions demonstrating IgH rearrangement. There were no human herpes virus type-8+ or human immunodeficiency virus type-1+ cells in any of the eight lesions. ISH demonstrated Epstein-Barr virus (EBV)-encoded small RNA (EBER)+ cells in only two lesions. PCR analyses demonstrated that there was no Toxoplasma gondii DNA in any of the eight lesions.

Conclusions

As suggested in RLHGF posttransplant, RLHGF arising after therapy for hematological malignancies is also a consequence of chronic stimulation in the setting of immune deregulation rather than various infectious agents. It is important for pathologists and clinicians to be aware of this type of lesion in diagnostic practice.

Lymphadenopathies in human immunodeficiency virus infection

This article describes the various non-neoplastic lymphadenopathies that occur in patients infected with the human immunodeficiency virus (HIV), before or during the stage of acquired immunodeficiency syndrome (AIDS). The stages that develop during the HIV infection include: primary infection (acute infection, spread of the virus, development of host immune response, and acute retroviral syndrome), chronic infection or clinical latency, and finally, the AIDS stage. Non-neoplastic lymphadenopathies can occur at any of these phases of the infection and are due to multiple causes that can be divided into infectious causes (bacterial, fungal, parasitic, viral), and reactive causes (persistent generalized lymphadenopathy and a variety of situations that they also occur in immunocompetent people such as Castleman's disease and Kikuchi-Fujimoto's disease, among others). The general, histological and immunophenotypic characteristics of these pathologies are described.

Clinical Implication of Idiopathic Plasmacytic Lymphadenopathy with Polyclonal Hypergammaglobulinemia: A Report of 16 Cases

Idiopathic plasmacytic lymphadenopathy (IPL) with polyclonal hyperimmunoglobulinemia is considered identical to multicentric Castleman's disease (MCD) reported in western countries. Clinically, both IPL and MCD are characterized by multicentric lymphadenopathy, prominent polyclonal hypergammaglobulinemia, elevated erythrocyte sedimentation rate, elevated serum interleukin-6 concentration, bone marrow plasmacytosis, and various abnormal laboratory data such as anemia and positive autoantibodies. However, IPL has a significantly better 5-year survival rate than that of MCD. Moreover, none of the present 16 cases developed Kaposi's sarcoma or B-cell lymphoma. Histologically, the interfollicular area contains a sheet of polytypic mature plasma cells in both IPL and MCD. In MCD, the majority of lymphoid follicles had hyaline-vascular germinal centers. However, lymphoid follicles of IPL usually exhibit a hyperplastic germinal center. Immunostaining also demonstrated a normal/ reactive follicular dendritic cell network pattern in the germinal center of IPL. Moreover, there were no human herpes virus-8-positive cells detected by immunohistochemistry. The overall clinicopathologic and immunohistochemical findings of our 16 cases suggest that IPL is distinct from MCD reported in Western countries.

Reactive Lymphoid Hyperplasia of the Lymph Nodes with Giant Follicles: A Clinicopathologic Study of 14 Japanese Cases, with Special Reference to Epstein-Barr Virus Infection

To clarify the clinicopathologic and immunohistochemical features of reactive lymphoid hyperplasia with giant follicles (RHGF) among Japanese, 14 patients were studied. The subjects consisted of 9 males and 5 females, ranging in age from 9 to 61 years, with a mean age of 30 years and a median age of 24 years. None of the patients exhibited systemic symptoms. The affected lymph nodes were located in the head and neck area except in 1 case. At the time of lymph node biopsy, 1 patient was diagnosed as having acute infectious mononucleosis (IM) and 2 patients had a recent history of acute IM. One each with myelogenous leukemia or diffuse large B-cell lymphoma had a history of peripheral blood stem cell transplantation. There were no recurrences during follow-up periods ranging from 3 to 50 months. Histologically, 14 lesions were characterized by numerous enlarged, coalescing lymphoid follicles with distortion rather than effacement of the lymph node architecture. By in situ hybridization, Epstein-Barr virus (EBV) genomes were demonstrated in 5 (36%) of 14 cases. The present study indicates that a portion of RHGF appears to represent a histologic finding of acute IM. Moreover, as previously stated, RHGF should be differentiated from follicular lymphoma, particularly the floral variant.

Clinical Implication of Florid Reactive Follicular Hyperplasia in Japanese Patients 60 Years or Older: A Study of 46 Cases

Florid reactive follicular hyperplasia (FRFH) of the enlarged lymph node in middle-aged or elderly patients requiring biopsy is a relatively uncommon phenomenon as compared with that in younger age groups. Between 1984 and January 2004, we encountered 46 patients, aged 60 years or older, in whom histology of biopsied lymph node specimens showed inappropriate FRFH for the patient’s age. An apparent cause of lymphadenopathy was initially identified in 17 cases (37%): 11 with autoimmune disease and related disorders, 3 with cancer-reactive lymphadenopathy, 2 with Epstein-Barr virus-associated lymph node lesion exhibiting transient autoimmune-disease-like clinical findings, and 1 with atypical mycobacterial infection. Among 29 patients without specific etiology, 16 patients (55%) exhibited histologic findings of progressive transformed germinal center (PTGC). Only 1 of our patients developed malignant lymphoma during the follow-up period. The present study indicates that PTGC is included in the etiology of FRFH in elderly Japanese patients as well as imbalance of the immune system such as autoimmune-disease-associated lymphadenopathy and idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia. By in situ hybridization, Epstein-Barr virus genomes were demonstrated in only 6 (15%) of 39 cases examined.

Lymphoid Tissue Mesenchymal Stromal Cells in Development and Tissue Remodeling

Secondary lymphoid organs (SLOs) are sites that facilitate cell-cell interactions required for generating adaptive immune responses. Nonhematopoietic mesenchymal stromal cells have been shown to play a critical role in SLO function, organization, and tissue homeostasis. The stromal microenvironment undergoes profound remodeling to support immune responses. However, chronic inflammatory conditions can promote uncontrolled stromal cell activation and aberrant tissue remodeling including fibrosis, thus leading to tissue damage. Despite recent advancements, the origin and role of mesenchymal stromal cells involved in SLO development and remodeling remain unclear.

Castleman-Kojima disease (TAFRO syndrome) : a novel systemic inflammatory disease characterized by a constellation of symptoms, namely, thrombocytopenia, ascites (anasarca), microcytic anemia, myelofibrosis, renal dysfunction, and organomegaly : a status report and summary of Fukushima (6 June, 2012) and Nagoya meetings (22 September, 2012)

Recently, a unique clinicopathologic variant of multicentric Castleman's disease (MCD) has been identified in Japan. This disease is characterized by a constellation of symptoms, as listed in the title, and multiple lymphadenopathy of mild degree with a pathologic diagnosis of atypical CD, often posing diagnostic and therapeutic problems for pathologists and hematologists, respectively. These findings suggest that this disease represents a novel clinical entity belonging to systemic inflammatory disorders with a background of immunological abnormality beyond the ordinal spectrum of MCD. To define this disorder more clearly, Japanese participants presented clinicopathologic data at the Fukushima and Nagoya meetings. Many of the patients presented by the participants were significantly accompanied by a combination of thrombocytopenia, ascites (anasarca), pleural effusions, microcytic anemia, fever, myelofibrosis, renal dysfunction, and organomegaly (TAFRO). Multiple lymphadenopathies were generally of mild degree, less than 1.5 cm in diameter, and consistently featured the histopathology of mixed- or less hyaline vascular-type CD. Autoantibodies were often detected. However, this disease did not fulfill the diagnostic criteria for well-known autoimmune diseases including systemic lupus erythematosus. Castleman-Kojima disease and TAFRO syndrome (the favored clinical term) were proposed for this disease. The patients were sensitive to steroid and anti-interleukin-6 receptor antibody (tocilizumab), but some exhibited a deteriorated clinical course despite the treatment. The participants proposed a future nationwide survey and a Japanese consortium to facilitate further clinical and therapeutic studies of this novel disease. [J Clin Exp Hematop 53(1): 57-61, 2013].

Complete resolution of TAFRO syndrome (thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly) after immunosuppressive therapies using corticosteroids and cyclosporin A : a case report

A 49-year-old woman with severe thrombocytopenia was admitted after an episode of syncope. She also had anemia, fever, pleural effusion and ascites, and multiple lymphadenopathies subsequently appeared. Her bone marrow showed increased megakaryocytes with mild fibrosis, whereas her lymph nodes lacked histologically specific findings. Her presentation was not consistent with multicentric Castleman's disease, angioimmunoblastic T-cell lymphoma, systemic lupus erhythematosus or any other well-recognized entities. Her clinical features were, however, thought to be compatible with TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) syndrome. Corticosteroid therapy induced a partial remission of fever and systemic fluid retention, but thrombocytopenia persisted. After additional immunosuppressive therapy with cyclosporin A, her symptoms showed full resolution. [J Clin Exp Hematop 53(1) : 95-99, 2013].

Multicentric Castleman's disease: a challenging diagnosis

Multicentric Castleman's disease (MCD) is a sytemic disorder with flares of non-specific symptoms suggestive of a chronic inflammatory syndrome. It is typically accompanied by generalized lymphadenopathy and multiorgan involvement. Histologically, two main variants of Castleman's disease exist, the hyalin vascular type and the plasma cell variant. Upon localization unicentric (localized), and multicentric (diffuse, systemic) subtypes can be distinguished with more different disease outcomes. Patients often exhibit acute phase reactions and several autoimmune phenomena, and are at high risk for developing malignancies. Both the idiopathic and the HHV-8-driven infectious forms of MCD represent distinct disease entities with a less favorable prognosis. The induction of human IL-6 excess via yet unknown upstream mechanisms, and overexpression of viral IL-6 by HHV-8 can pivotally influence MCD biology. Based on the role of IL-6 in pathogenesis, MCD is also designated as IL-6 lymphadenopathy. To date there are no direct therapeutic evidences, but having been translated to daily practice the main regulatory factors may serve as promising therapeutic targets.

Pathobiology of HIV/SIV-associated changes in secondary lymphoid tissues

Acquired immunodeficiency syndrome (AIDS) is principally a disease of lymphoid tissues (LTs), due to the fact that the main target cell of human immunodeficiency virus (HIV) is the CD4(+) T lymphocyte that primarily resides within organs of the immune system. The impact of HIV infection on secondary LTs, in particular lymph nodes, is critical to delineate, as these immune organs are the principal sites for initiating and facilitating immune responses and are critical for lymphocyte homeostatic maintenance and survival. The underlying structural elements of LTs, fibroblastic reticular cell (FRC) network, not only form the architectural framework for these organs, but also play in integral role in the production and storage of cytokines needed for T-cell survival. There is an interdependent relationship between the FRC stromal network and CD4(+) T lymphocytes for their survival and maintenance that is progressively disrupted during HIV disease. HIV infection results in profound pathological changes to LTs induced by persistent chronic immune activation and inflammation that leads to progressive collagen deposition and fibrosis disrupting and damaging the important FRC network. In this review, I focus on the process, mechanisms, and the implications of pathological damage to important secondary LTs, combining what we have learned from HIV-infected individuals as well as the invaluable knowledge gained from studies in non-human primate simian immunodeficiency virus infection models.

Plasmacytoid dendritic cells in lymph nodes of patients with human immunodeficiency virus

Circulating plasmacytoid dendritic cells (PDC) decrease in human immunodeficiency virus (HIV) infection, either from loss or redistribution to lymph nodes (LN). Limited animal and human studies variably showed increased or decreased nodal PDC. CD123 immunostaining was performed on 28 archived LN biopsies (20 reactive) from 25 HIV patients. PDC clustering was graded (1: none; 2: rare small; 3: medium-sized, loose; and 4: large tight clusters) and correlated with HIV-lymphadenitis stage, blood CD4 counts, time since HIV diagnosis, and treatment duration. Increased PDC clustering was seen with decreasing CD4 counts (P = 0.001), shorter treatment duration (P = 0.0268), and advancing HIV-lymphadenitis stage (P = 0.06). No correlation with time since HIV diagnosis was noted. To our knowledge, this is the first human study assessing relationship of nodal PDC in HIV to CD4 counts, treatment duration, and lymphadenitis pattern. Our findings suggest that PDC redistribute to LN with advancing immunodeficiency and stage of HIV infection.

Lymphoid Proliferations Associated With Human Immunodeficiency Virus Infection

Context.—Individuals who are immune deficient are at an increased risk for developing lymphoproliferative lesions and lymphomas. Human immunodeficiency virus (HIV) infection is 1 of 4 clinical settings associated with immunodeficiency recognized by the World Health Organization (WHO) in which there is an increased incidence of lymphoma and other lymphoproliferative disorders.

Objectives.—To describe the major categories of benign lymphoid proliferations, including progressive HIV-related lymphadenopathy, benign lymphoepithelial cystic lesions, and multicentric Castleman disease, as well as the different types of HIV-related lymphomas as defined by the WHO. The characteristic morphologic, immunophenotypic, and genetic features of the different entities will be discussed in addition to some of the pathogenetic mechanisms.

Data Sources.—The WHO classification of tumors of hematopoietic and lymphoid tissues (2001 and 2008), published literature from PubMed (National Library of Medicine), published textbooks, and primary material from the authors' current and previous institutions.

Conclusions.—HIV infection represents one of the clinical settings recognized by the WHO in which immunodeficiency-related lymphoproliferative disorders may arise. Although most lymphomas that arise in patients with HIV infection are diffuse, aggressive B-cell lesions, other lesions, which are “benign” lymphoid proliferations, may also be associated with significant clinical consequences. These lymphoproliferations, like many other immunodeficiency-associated lymphoproliferative disorders, are often difficult to classify. Studies of HIV-associated lymphoid proliferations will continue to increase our understanding of both the immune system and lymphomagenesis.

Granulomatous lymphadenitis

In this review, representative types of granulomatous lymphadenitis (GLA) are described. GLA can be classified as noninfectious GLA and infectious GLA. Noninfectious GLA includes sarcoidosis and sarcoid-like reaction. The cause of sarcoidosis remains unknown, but it has good prognosis. Sarcoid-like reaction, which is considered to be a biological defense mechanism, is observed in regional lymph nodes with many underlying diseases. Infectious GLA can be classified as suppurative lymphadenitis (LA) and nonsuppurative LA. Suppurative LA generally shows follicular hyperplasia and sinus histiocytosis in the early phase. In tularemia and cat scratch disease, monocytoid B lymphocytes (MBLs) with T cells and macrophages contribute to the formation of granuloma. However, none of the epithelioid cell granulomas of Yersinia LA contains MBLs like in cat scratch disease. In addition, almost all have a central abscess in granulomas induced by Gram-negative bacteria. In terms of the lymph nodes, tularemia and cat scratch disease are apt to affect the axillary and cervical regions while Yersinia LA affects the mesenteric lymph node. Nonsuppurative LA includes tuberculosis and BCG-histiocytosis. These are induced by delayed allergic reaction of M. tuberculosis. Tuberculosis LA mainly appears in the cervical lymph node. Organisms are histologically detected by Ziehl-Neelsen staining in the necrotic area. Toxoplasmosis is also a nonsuppurative protozoan infection (Toxoplasma gondii). In toxoplasma LA, MBLs can also be seen, but round and organized, well-formed granulomas are not found in this disease. Furthermore, necrosis is not induced and there are no accompanying neutrophils, eosinophils and fibrosis. GLA described above is associated with characteristic histological findings. An accurate pathological diagnosis using the above findings can lead to precise treatment.

Lymphoproliferative Lesions in the Setting of HIV Infection: A Five-Year Retrospective Case Series and Review

A wide variety of noninfectious lesions have been identified in association with HIV infection. Many hematolymphoid lesions are possible in this patient group, both reactive and neoplastic. Epidemiologic data suggests that lymphoid malignancies are among the most common neoplasms in patients with HIV. We present a selective case series assembled over a 5-year period from the relatively low HIV-prevalence Hamilton Regional Laboratory Medicine Program (HRLMP), a tertiary care referral centre in Southern Ontario. This series serves to demonstrate the wide variety of lymphoid lesions that may be encountered in patients with HIV. In addition to outlining the pathologic work-up necessary in these cases, we discuss characteristics that distinguish the HIV-associated lesions from the pathobiologically similar non-HIV-associated lymphoid lesions.

Multicentric Castleman's disease representing effusion at initial clinical presentation: clinicopathological study of seven cases

We present here seven cases of idiopathic multicentric Castleman's disease (MCD) showing effusion at the initial clinical presentation. This series includes a high proportion of middle-aged and elderly females (5/7). Various autoantibodies were detected in six cases. Anemia (Hb < 10 g/dl) was detected in four cases, leukocytosis (WBC > 10 × 10(9)/l) in three and thrombycytopenia (<100 × 10(9)/l) in five. Positivity for C-reactive protein or elevated erythrocyte sedimentation rate was recorded in all seven cases. Elevated serum IgG level (>2000 mg/dl) was recorded in only three cases. Elevated serum interleukin-6 level was recorded in all four cases examined. At the onset of disease, four cases were associated with idiopathic thrombocytic purpura. During the course of disease, one case each was diagnosed as systemic sclerosis + Sjögren's syndrome (SJS) and SJS. Histologically, five lesions exhibited a mixed type of Castleman's disease, and one case each exhibited a hyaline-vascular type and plasma cell type. The non-neoplastic nature of the B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. There were no human herpes type-8 virus-positive cells in any of the seven lesions. Good responsiveness to glucocorticoid therapy has been seen in all six cases treated. From a therapeutic perspective, it is important to discriminate this subtype of MCD.

A case of HIV-associated lymphoproliferative disease that was successfully treated with highly active antiretroviral therapy

We report a case of a 41-year-old male with human immunodeficiency virus (HIV)-associated lymphoproliferative disease (LPD) who was successfully treated with highly active antiretroviral therapy (HAART). He presented with epigastralgia, and an upper endoscopic examination revealed submucosal tumors and ulcerations in his stomach. Histopathologic examination of a biopsy specimen resulted in a diagnosis of diffuse large B-cell lymphoma. He also showed systemic lymphadenopathy; whereas, a concurrent inguinal lymph node biopsy produced a diagnosis of follicular hyperplasia. He was treated with CHOP chemotherapy but the response was poor. He demonstrated several immunological abnormalities, such as eosinophilia and bone marrow insufficiency, and was suspected to be in an immunocompromised state. He was examined for HIV infection and turned out to be positive. The gastric and inguinal lymph node specimens were re-evaluated and diagnoses of HIV-LPD and HIV lymphadenitis were made, respectively. He was treated with HAART and achieved complete remission and has remained tumor-free for 20 months. To the best of our knowledge, there is no previous report in which HIV-LPD was successfully treated with antiretroviral therapy alone. It is assumed that HAART resulted in the restoration of anti-tumor immunity in this case, which led to the eradication of LPD cells.

Burkitt's lymphoma: the Rosetta Stone deciphering Epstein-Barr virus biology

Epstein-Barr virus was originally identified in the tumour cells of a Burkitt's lymphoma, and was the first virus to be associated with the pathogenesis of a human cancer. Studies on the relationship of EBV with Burkitt's lymphoma have revealed important general principles that are relevant to other virus-associated cancers. In addition, the impact of such studies on the knowledge of EBV biology has been enormous. Here, we review some of the key historical observations arising from studies on Burkitt's lymphoma that have informed our understanding of EBV, and we summarise the current hypotheses regarding the role of EBV in the pathogenesis of Burkitt's lymphoma.

The effects of acute malaria on Epstein-Barr virus (EBV) load and EBV-specific T cell immunity in Gambian children

BACKGROUND

To investigate how intense Plasmodium falciparum infection predisposes to Epstein-Barr virus (EBV)-positive Burkitt lymphoma (BL), we analyzed the effect of acute malaria on existing EBV-host balance.

METHODS

EBV genome loads in peripheral blood mononuclear cells were assayed by quantitative polymerase chain reaction, and EBV-specific CD8(+) T cell responses were assayed by interferon-gamma enzyme-linked immunospot assay.

RESULTS

Gambian children, from whom samples were obtained during an acute malaria attack and again up to 6 weeks later, had extremely high viral loads, reaching levels that in the United Kingdom are seen only in patients with infectious mononucleosis. Gambian control subjects (children and adults with no recent history of malaria) had lower median viral loads, although they were still >10-fold above the median for healthy UK adults. Limited experiments with EBV epitope peptides (restricted through the HLA-B 3501 and HLA-B 5301 alleles) also suggested an impairment of virus-specific CD8(+) T cell function in children with malaria, but only during acute disease.

CONCLUSIONS

Acute malaria is associated with sustained increase in EBV load and, possibly, a transient decrease in EBV-specific T cell surveillance. We infer that the unusually high set point of virus carriage in P. falciparum-challenged populations, allied with the parasite's capacity to act as a chronic B cell stimulus, probably contributes to the pathogenesis of endemic BL.

Clinical implications of idiopathic multicentric castleman disease among Japanese: a report of 28 cases

To clarify the clinicopathologic findings of idiopathic multicentric Castleman disease among Japanese, 28 cases were studied. Two variants were delineated by the clinicopathologic findings (1) idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (n = 18) and (2) nonidiopathic plasmacytic lymphadenopathy type (n= 10). Clinicopathologically, idiopathic plasmacytic lymphadenopathy was defined by the prominent polyclonal hyperimmunoglobulinemia, normal germinal centers, and sheet-like infiltration of plasma cells in the interfollicular area of the lymph node. Histologically, the nonidiopathic plasmacytic lymphadenopathy type was characterized by hyaline-vascular germinal centers of the lymph node lesion. In comparison with idiopathic plasmacytic lymphadenopathy, patients with nonidiopathic plasmacytic lymphadenopathy showed infrequent prominent polyclonal hyperimmunoglobulinemia and frequent association with autoimmune disease. However, there was no difference in the overall 5-year survival between the 2 subtypes. Compared with idiopathic multicentric Castleman disease in Western countries, the chronic course of the disease of idiopathic multicentric Castleman disease in Japan appears to be related to negativity for human herpesvirus 8 infection.

Lymphoreticular Involvement in Human Immunodeficiency Virus Infection

BACKGROUND

Although lymphadenopathy, hepatomegaly and splenomegaly are commonly seen in human immunodeficiency virus (HIV) infection, little is known about the prognostic significance of these findings.

METHOD

A retrospective study of lymphoreticular involvement in 612 HIV-positive patients was done.

RESULT

Lymphadenopathy was found in 301 (49.18%), hepatomegaly in 102 (16.66%) and splenomegaly in 58 (9.47%) patients. Sixty eight (32.54%) of the 209 patients with only lymphadenopathy had acquired immunodeficiency syndrome (AIDS), as compared to 70 (23.97%) of the 292 patients without lymphadenopathy or hepatosplenomegaly (χ(2) 4.49, df-1, p<0.05). There was a higher chance of having AIDS if hepatomegaly was present with lymphadenopathy. Eight (72.73%) of 11 patients with hepatomegaly alone, had AIDS. Thirty (68.18%) of 44 cases with splenomegaly, with lymphadenopathy and hepatomegaly, three (50%) of six cases having splenomegaly with lymphadenopathy and one (33.33%) of three cases with splenomegaly had AIDS. Majority of lymphoreticular involvement cases were due to Mycobacterium tuberculosis infection. All 29 cases with abdominal lymphadenopathy and one with hilar lymphadenopathy had AIDS. Bilateral discrete cervical, axillary and inguinal lymphadenopathy was the most common presentation. CD4 counts were significantly (p<0.05) lower in those with lymphadenopathy and hepatosplenomegaly.

CONCLUSION

HIV cases with lymphadenopathy and hepatomegaly should be investigated for the presence of opportunistic infection.

Burkitt lymphoma: revisiting the pathogenesis of a virus-associated malignancy

Burkitt lymphoma (BL), a tumor occurring in endemic, sporadic and AIDS-associated forms, is the classic example of a human malignancy whose pathogenesis involves a specific cellular genetic change, namely, a chromosomal translocation deregulating expression of the c-myc oncogene, complemented in many cases by the action of an oncogenic virus, the Epstein-Barr virus (EBV). Here we review recent work in two complementary areas of research: (1) on cellular genetic changes that occur in addition to the c-myc translocation in BL, in particular the capacity of p53/ ARF pathway breakage or of c-myc mutation to decouple the pro-proliferative effects of c-myc deregulation from its pro-apoptotic effects; and (2) on a postulated role for EBV in BL pathogenesis, through adopting restricted forms of virus latent gene expression that remain compatible with the c-myc-driven growth program but offer the tumor additional protection from apoptosis. We stress the many fundamental questions that remain to be resolved and, in that regard, highlight the general lessons that might be learned through understanding how two other infectious agents, malaria and HIV, dramatically enhance BL incidence.

Reactive hyperplasia with giant follicles in lymph node lesions from systemic lupus erythematosus patients. Report of three cases

Lymph node enlargement is common in active systemic lupus erythematosus (SLE), a disease that is characterized by well-defined clinical criteria. Histologically, although lymphadenopathy associated with SLE exhibits marked histological diversity and occasionally shows atypical lymphoproliferative disorders, there has not been any description of the histopathological features of reactive lymph node hyperplasia with giant follicles (RHGF). We here report three such cases. The subjects were a 23-year-old Japanese female, a 44-year-old Japanese female and a 49-year-old Japanese male. All three patients initially presented with systemic lymphadenopathy. They also had systemic symptoms and abnormal laboratory findings indicating active disease, although two patients did not fulfill the diagnostic criteria for SLE at lymph node biopsy. Histologically, three lesions were characterized by numerous enlarged, coalescing lymphoid follicles with distortion rather than effacement of the lymph node architecture. By in situ hybridization, Epstein-Barr virus (EBV) genomes were demonstrated in two cases. The present three cases indicate that lymphadenopathy associated with SLE representing RFGH should be differentiated from the early stage of HIV-related lymphadenopathy as well as follicular lymphoma, particularly the floral variant. The authors would like to stress that the RHGF which is described in the present study should be listed in the pathohistology of SLE lymphadenopathy.

Idiopathic multicentric Castleman's disease. A clinicopathologic and immunohistochemical study of five cases

Several lymphoproliferative disorders may be interpreted as multicentric Castleman's disease (MCD) clinicopathologically. These include HIV infection, autoimmune-disease-associated lymphadenopathy, idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia, "idiopathic MCD", POEMS syndrome (polyneuropathy, anasarca, organomegaly, endocrinopathy, M-proteins, and skin lesions), and non-Hodgkin's lymphomas. Among these, idiopathic MCD appears to be relatively rare. We report on the clinicopathologic and immunohistologic findings of five cases of idiopathic MCD and discuss the problems regarding their differential diagnosis. Some of the characteristic clinical findings of POEMS syndrome, including hepatosplenomegaly, skin change, endocrine abnormalities and anasarca, were present in all five cases. However, during the course of disease, minimal diagnostic criteria for POEMS syndrome, i.e., monoclonal plasma cell proliferation and sensory motor neuropathys, were absent in all five cases. The serum interleukin-6 level and the vascular endothelial growth factor level were found to be elevated in two of the cases examined. Various autoantibodies were detected in three cases. However, none of them fulfilled the diagnostic criteria for any of the definite autoimmune-disease. Histologically, three lesions exhibited a mixed type of Castleman's disease, and two exhibited the hyaline-vascular type. The majority of the germinal centers were of the hyaline-vascular or epithelioid germinal type, with a few hyperplastic germinal centers. The interfollicular area was characterized by prominent vascularity. Moderate to large sheets of plasma cells were observed in three mixed type cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. Immunohistochemical study demonstrated that the majority of germinal centers exhibited a tight/concentric pattern of FDC network. Few CD57-positive T-cells were observed in the hyaline-vascular and epithelioid follicles. The lack of CD57-positive T-cells appears to be related to the formation of abnormal germinal centers in the MCD.

Non-Hodgkin lymphoma in Uganda: a case-control study

BACKGROUND

Lymphomas are a relatively common complication of AIDS in western countries, but little is known of the impact of the AIDS epidemic in Africa on the risk of these tumours.

OBJECTIVE

To investigate the types of non-Hodgkin lymphoma (NHL) occurring in Kampala, Uganda, their association with Epstein-Barr virus (EBV), and how their risk is modified by HIV and other variables.

METHODS

A case-control study comparing NHL cases with age/sex-matched controls. Lymphoma cases included 50 histologically diagnosed adults (31 with validation and phenotyping) and 132 histologically diagnosed children (61 with validation and phenotyping). Controls were adults with cancers unrelated to HIV and children with non-infectious diseases.

RESULTS

Most (90%) childhood lymphomas were EBV-positive Burkitt's lymphoma (BL), with no association with HIV. Adult lymphoma cases were mainly BL (mostly EBV positive) or diffuse B cell lymphomas (71%). Only a weak association was found with HIV infection; a more precise estimate was obtained with the total series (OR 2.2, 95% CI 0.9-5.1) than validated/phenotyped cases (OR 2.1, 95% CI 0.3-6.7). Higher socioeconomic status adults, who travelled away from home, or had a history of sexually transmitted diseases, appeared to have a moderately increased risk of lymphoma.

CONCLUSION

Childhood lymphomas were predominantly endemic BL, the risk of which was not modified by HIV. In adults, the risk associated with HIV was much lower in Uganda than in western countries, possibly because of the poor survival of immunosuppressed HIV-positive individuals. Future studies will require careful attention to subtyping of lymphomas, to investigate the possible differences between them.

EBV-associated primary lymphomas in salivary glands of HIV-infected patients

The lymph nodes within and around salivary glands are commonly involved in inflammatory processes, but rarely the site of primary lymphomas. We observed six cases of primary salivary gland lymphoma in HIV-infected patients and studied them in parallel with three cases of primary salivary gland lymphoma unrelated to HIV and three cases of HIV-related salivary gland lymphadenopathies in order to characterize this new entity. We found that all salivary gland lymphomas in HIV-infected patients were of high histologic grade while salivary gland lymphomas unrelated to HIV were predominantly of low grade MALT type. All lymphomas in both categories expressed the B-cell phenotype. Just as HIV-unrelated lymphomas frequently arise on the background of chronic inflammatory lymphoid processes, lesions characteristic of HIV-lymphadenopathy were still present in some lymphomas of HIV-infected patients. EBV RNA transcripts (EBER) were demonstrated in three, and latent membrane protein (LMP) in two of the six HIV-related and in none of the three HIV-unrelated lymphomas. The three EBER-positive lymphomas were of the histologic types known to express the virus in most cases. The presence of HIV in the form of the core protein p24 and envelope glycoprotein gp41 on the dendritic reticular cells of germinal centers was ascertained in the cases of HIV-related lymphadenopathies but also in the coexistent lymphadenopathies of lymphomas. The practical importance of diagnosing the salivary lymphadenopathies and lymphomas associated with the HIV-infection resides in avoiding their misdiagnosis and surgical removal as tumors of salivary glands.

Splenic para-amyloid material: a possible vasculopathy of the acquired immunodeficiency syndrome

We have observed perivascular para-amyloid in the spleens of acquired immune deficiency syndrome (AIDS) patients at autopsy. Whether this phenomenon is unique to AIDS patients or is a common degenerative phenomenon in the spleen has not been determined. Autopsy spleens from 355 patients (171 AIDS, 184 non-AIDS) were graded for presence of splenic para-amyloid material (SPAM) on a scale of 0 to 3. The average ages of the AIDS and non-AIDS groups were 38.4 and 60.4 years, respectively. All SPAM-positive AIDS cases had age-matched non-AIDS controls. Selected positive cases were examined ultrastructurally. Of the 171 AIDS patients, 55 had SPAM; in 30 cases, it was considered grade 2 or 3. Although none of the non-AIDS cases were graded 2 or 3, eight of them were grade 1. SPAM is highly correlated with AIDS (32.1 v 4.3%; P < .0001), with a specificity of 95.6% and a positive predictive value of 87.3%. These perivascular deposits correspond to areas of periarteriolar lymphoid sheaths and appear to be in continuity with arteriolar adventitia. Ultrastructurally, they contain collagen, long-spaced collagen, fibrillin, and occasional residual cells. No viral particles were noted. SPAM appears to be more prevalent and in greater quantity in AIDS patients. It does not correlate with advanced age; it can be mistaken for amyloid. Its consistent association with the adventitia of vessels raises the possibility of a new vasculopathy of AIDS; it also may be related to follicular involution and hyalinization associated with regression of prior follicular hyperplasia.

Development of lymphoid hyperplasia in transgenic mice expressing the HIV tat gene

During HIV infection, individuals experience multiorgan disorders such as adenopathy, splenomegaly, and lung and brain diseases. There is an increasing body of evidence that the HIV trans-activating tat gene product possesses multiple activities. First, it can activate several cellular genes; second, in its extracellular soluble form, it plays the role of growth factor in some cells such as Kaposi's sarcoma cells. Thus, we introduced the HIV tat gene, under the control of the cellular proteolipoprotein promoter, into the germline of mice and demonstrate that, when expressed, the tat gene product induces lymphoid hyperplasia in spleen, lymph nodes, and lung, as is observed in AIDS patients, but not in the brain or testes. Our findings indicate that HIV, through some of its genes, directly participates in the pathogenesis of AIDS.

The maedi-visna virus Tat protein induces multiorgan lymphoid hyperplasia in transgenic mice

Sheep infected with maedi-visna virus experience immunological disorders leading to progressive chronic diseases involving the brain, lung, spleen, and lymph nodes. To study the biological activity of the viral transactivating Tat protein, we generated transgenic mice carrying the tat gene. Analysis of the transgenic mouse tissues for tat mRNA revealed that while low at the messenger level, the expression of the transgene correlated with dramatic follicular lymphoproliferative disorders involving the lung, spleen, lymph nodes, and skin. This finding suggests that the viral protein possesses a high pathological potency. Our findings show that the maedi-visna virus tat gene product contributes to the pathogenesis of multiorgan proliferative disorders associated with maedi-visna virus infection.

Characterization of morphologic changes and lymphocyte subset distribution in lymph nodes from cats with naturally acquired feline immunodeficiency virus infection

Lymph nodes were collected at biopsy or necropsy from 18 cats with naturally acquired symptomatic feline immunodeficiency virus (FIV) infection and from 18 seronegative cats. Thirty-five of the cats were domestic shorthairs and one was a Persian cross. The cats ranged from 7 months to 16 years of age and were mainly obtained from California veterinary practitioners, a California cattery, and a Veterinary Teaching Hospital. Based on clinical signs present at tissue collection, ten FIV-infected cats fell into the acquired immunodeficiency syndrome (AIDS)-related complex (ARC) clinical stage and eight in the terminal (AIDS) stage of FIV disease. All cats were FeLV negative by antigen ELISA. Histologic sections of lymph nodes from each cat were examined blindly and were categorized as hyperplastic, involuting, mixed hyperplastic and involuting, depleted, or normal based upon subjective evaluation of follicles and paracortex. The relative abundance of plasma cells was evaluated in methyl green pyronin (MGP) and hematoxylin and eosin-stained sections. Similar numbers of FIV-seropositive and -seronegative cats fell into each lymph node category. The only difference evident between FIV-infected cats and control cats was in the degree of plasmacytosis present; moderate to marked plasmacytosis was present in 13/18 FIV-infected cats but in only 3/18 control cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural pathology of human immunodeficiency virus infection

The electron microscope has been used with great skill in many aspects of the acquired immunodeficiency syndrome. It has played a critical role in classifying the human immunodeficiency virus, in characterizing the morphogenesis and gene products of the virus, and in elucidating the host cell targets and interactions. With the aid of the electron microscope, new opportunistic pathogens are being identified, and particularly difficult diagnoses are being made. Extrapolations from observations made at the ultrastructural level to the light microscopic level have provided criteria for the diagnosis of several infectious agents. As with any powerful scientific tool, observations must be interpreted with great care by scientists experienced in electron microscopy.

Syndrome of severe skin disease, eosinophilia, and dermatopathic lymphadenopathy in patients with HTLV-II complicating human immunodeficiency virus infection

Two intravenous drug users dually infected with human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type II (HTLV-II) developed an unusual severe dermatitis characterized by progressive brawny induration, fissuring, and ulceration of the skin, with an associated CD8 cell infiltration in one patient. Both patients had persistent eosinophilia. Lymph node biopsy revealed dermatopathic lymphadenopathy, an unusual pathologic finding in HIV-1 infection but one seen in association with mycosis fungoides and other skin disorders. Two new isolates of HTLV-II virus were established from these patients and were identified as HTLV-II by Southern blotting. This type of skin disease and lymph node pathology has not been found in other intravenous drug users who have been infected with HIV-1 alone or in patients in other risk groups for HIV-1 infection. HTLV-II may play a role in this unique new disease pattern in patients infected with HIV-1.

Acquired immunodeficiency syndrome-associated lymphomas: clinical, pathologic, immunologic, and viral characteristics of 111 cases

The incidence of lymphomas in individuals infected with the human immunodeficiency virus has increased progressively since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic. The present series includes 111 patients, all diagnosed and studied at one hospital in New York City. There were 108 men and three women; the average age was 39 years and male homosexuality was the predominant risk factor. The materials examined originated from 138 surgical specimens and 24 autopsies. There were 11 cases of Hodgkin's lymphoma and 100 cases of non-Hodgkin's lymphomas (NHL), a proportion strongly skewed in favor of the latter. Hodgkin's lymphoma in AIDS patients was characterized by advanced clinical stage, high histologic grade, and frequent bone marrow involvement. Non-Hodgkin's lymphoma in AIDS patients, in contrast to the general population, originated predominantly in extranodal locations (61 cases) versus locations in which the lymph nodes were the site of the primary tumors (39 cases). In the digestive tract, the unusual oral and anal primary locations were often noted and were possibly related to specific risk factors. There were 15 cases of NHL of the central nervous system, an incidence 14 times greater than that recorded in the general population. The majority of NHLs were of high histologic grade, Burkitt's and large cell immunoblastic, representing most of the cerebral and gastrointestinal tumors. All NHLs were of B-cell immunophenotype. Lymphadenopathies with the histologic features of human immunodeficiency virus infection, particularly of the late stage (type C), often preceded NHL. Probing for Epstein-Barr virus genome was more frequently positive in Hodgkin's lymphoma than in NHL. Immunologic evaluations showed severely depressed T cell counts and CD4 to CD8 cell ratios as well as markedly increased levels of antilymphocyte antibodies. Reflecting the background of profound immune deficiency, the AIDS-associated lymphomas were characterized by high aggressiveness, early tendency to generalization, frequent post-treatment relapse, and short periods of survival.