Multicentric angiofollicular lymph node hyperplasia (Castleman's disease) followed by Kaposi's sarcoma in two homosexual males with the acquired immunodeficiency syndrome (AIDS)

Immunology and targeted therapy in Castleman disease

INTRODUCTION

Castleman disease (CD) is a benign lymphoproliferative disease causing severe systemic inflammation. Interleukin-6 (IL-6) is a major pathogenesis of multicentric CD (MCD), but only 30-60% of patients respond to IL-6 inhibitors. Novel agents for IL-6 inhibitor-refractory cases are needed. Clinical data and samples are being collected on a large scale and the clinical, pathological, and pathogenetic aspects are being elucidated.

AREAS COVERED

The pathological and clinical classification of CD is outlined. Focusing on idiopathic MCD (iMCD), this review identifies therapeutic targets and summarizes currently recommended drugs and promising therapeutic candidates.

EXPERT OPINION

The pathogenesis of MCD has been implicated in the activation of the Janus kinase (JAK)-transcriptional signaling activator (STAT) 3 pathway and the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanical target of rapamycin (mTOR) signaling pathway. iMCD-TAFRO (thrombocytopenia, anasarca, fever/elevated CRP, reticulin myelofibrosis/renal dysfunction, organ enlargement) is resistant to IL-6 inhibitors, and cyclosporine and mTOR inhibitors are sometimes effective. JAK inhibitors and mTOR inhibitors may be therapeutic agents for iMCD. Recently, we have shown that peripheral helper T (Tph) cell abnormalities are at the core of iMCD pathogenesis. Therapies targeting chemokine (C-X-C motif) ligand 13 (CXCL13) produced by Tph cells and blocking the Tph-CXCL13-B cell pathway may satisfy unmet need in refractory cases.

The application of a multidisciplinary approach in the diagnosis of Castleman disease and Castleman-like lymphadenopathies: A 20-year retrospective analysis of clinical and pathological features

BACKGROUND

Castleman disease (CD) comprises a group of rare and heterogeneous haematological disorders, including unicentric (UCD) and multicentric (MCD) forms, the latter further subdivided into HHV8-MCD, POEMS-MCD and idiopathic-MCD (iMCD). However, according to the Castleman Disease Collaborative Network guidelines, the diagnosis of CD can only be achieved through collaboration between clinicians and pathologists.

METHODS

We applied these clinical and pathological criteria and implement with clonality testing to a retrospective cohort of 48 adult and paediatric Italian patients diagnosed with reactive lymphadenitis with CD-like histological features.

RESULTS

We confirmed the diagnosis of CD in 60% (29/48) of the cases, including 12 (41%) UCD and 17 (59%; five HHV8-MCD, three POEMS-MCD and nine iMCD) MCD. Of the remaining 19 cases (40%) with multiple lymphadenopathy, 5 (26%) were classified as autoimmune diseases, 1 (5%) as autoimmune lymphoproliferative disorder, 1 (5%) as IgG4-related disease, 11 (83%) as reactive lymphadenitis and 1 (5%) as nodal marginal zone lymphoma.

CONCLUSIONS

Our study emphasizes the importance of the multidisciplinary approach to reactive lymphadenitis with CD-like features in order to achieve a definitive diagnosis and choose the appropriate treatment.

Retroperitoneal paraduodenal unicentric Castleman disease: case report and review of the literature

Castleman disease is a rare and benign disorder, characterized by enlarged lymph nodes and angiofollicular lymphoid hyperplasia. We report a case of a 57-year-old male, who was admitted to our surgical department because of a retroperitoneal nodular mass measuring about 4 cm in maximum diameter, incidentally discovered on a radiologic exam performed for the onset of vague abdominal pain with posterior irradiation. The patient was subdue to laparoscopic removal of the mass and no intra- and post-operative complications were recorded. Histologic diagnosis of hyaline-vascular variant of the Castleman disease was confirmed. Only two cases have been found in the literature reporting the paraduodenal unicentric Castleman disease localization like our case. Although rare, the Castleman disease must be considered in the differential diagnosis among all the lymph nodes diseases, for avoiding improper therapies.

HHV-8-associated multicentric Castleman disease with concurrent Kaposi sarcoma

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder typically manifesting with bulky lymphadenopathy in multiple lymph node stations. We describe an atypical presentation of human herpes virus 8 (HHV8)-associated MCD in a middle-aged man with no significant medical history who presented with 1 month of systemic symptoms. He was found to be HIV-1 positive. A physical examination did not reveal palpable lymphadenopathy. A contrast-enhanced CT scan was notable for hepatosplenomegaly and mildly enlarged scattered lymph nodes in the abdomen and pelvis. A positron emission tomography/CT scan demonstrated hypermetabolic cervical chain lymph nodes. Posterior cervical lymph node pathology showed HHV8-positive MCD with concurrent HIV-associated Kaposi sarcoma. The patient was treated with rituximab and liposomal doxorubicin without response. We emphasise the lack of the hallmark of bulky lymphadenopathy in this patient, and the importance of a timely pathological diagnosis in MCD.

Historical and pathological overview of Castleman disease

Castleman disease consists of several lymphoproliferative subtypes that share some histological features in the lymph nodes. On the other hand, numerous clinical findings and etiologies make the disease challenging to understand. The origin of the disease is the hyaline vascular-type unicentric Castleman disease (UCD), first reported by Benjamin Castleman et al. in 1954. Although UCD is characterized by localized lesions and lack of symptoms, multicentric Castleman disease (MCD) with multiple lesions and systemic symptoms was reported by Frizzera in 1983. MCD is further divided according to KSHV/HHV8 infection status. In KSHV/HHV8-related MCD, viral infection signals lead to excessive cytokine production, and cause clinical and pathologic abnormalities. Some cases of plasma cell-type KSHV/HHV8-negative MCD can be found in association with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-proteins, and skin changes), which is a paraneoplastic syndrome. The others are idiopathic MCD, which are currently considered a heterogeneous group of diseases with overlapping pathological and clinical features. In this article, we summarize the historical evolution of Castleman disease to help understand the disease concept. We also review the latest ideas and definitions of the subtypes within the MCD spectrum and summarize the histopathological findings.

POEMS Syndrome: Presented as Idiopathic Multicentric Castleman Disease of Plasma Cell Variant for Eight Years and Dramatic Treatment with Siltuximab Followed by Autologous Peripheral Blood Stem Cell Transplantation

Background: POEMS syndrome (POEMS) is a rare plasma cell clonal paraneoplastic syndrome consisting of polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes presenting with idiopathic multicentric Castleman disease (iMCD) histology, the treatment of which has not yet been well established. iMCD is also a distinctive rare non-clonal lymphoproliferative disorder, of which dramatic response to Siltuximab, a monoclonal anti-IL-6 antibody, has been reported recently. Methods: the differential diagnosis between POEMS and iMCD can be very challenging because of the identical histology, overlapping similar symptoms such as polyneuropathy, and vital signs insidiously presented to diagnose POEMS. Results: here, we report the case of a 53-year-old man with iMCD treated for 8 years developing sequential polyneuropathy, monoclonal gammopathy, and bone lytic lesions, all of which were confirmed after his iMCD achieved complete remission resulting from siltuximab administration and finally confirmed as POEMS. Conclusions: we describe the clinical ambiguity of disease presenting that we can face in the real world between iMCD and POEMS and emphasise careful, enduring observation lasting several years.

KSHV/HHV8-mediated hematologic diseases

Kaposi sarcoma (KS) herpesvirus (KSHV), also known as human herpesvirus 8, is the causal agent of KS but is also pathogenetically related to several lymphoproliferative disorders, including primary effusion lymphoma (PEL)/extracavitary (EC) PEL, KSHV-associated multicentric Castleman disease (MCD), KSHV+ diffuse large B-cell lymphoma, and germinotropic lymphoproliferative disorder. These different KSHV-associated diseases may co-occur and may have overlapping features. KSHV, similar to Epstein-Barr virus (EBV), is a lymphotropic gammaherpesvirus that is preferentially present in abnormal lymphoid proliferations occurring in immunecompromised individuals. Notably, both KSHV and EBV can infect and transform the same B cell, which is frequently seen in KSHV+ EBV+ PEL/EC-PEL. The mechanisms by which KSHV leads to lymphoproliferative disorders is thought to be related to the expression of a few transforming viral genes that can affect cellular proliferation and survival. There are critical differences between KSHV-MCD and PEL/EC-PEL, the 2 most common KSHV-associated lymphoid proliferations, including viral associations, patterns of viral gene expression, and cellular differentiation stage reflected by the phenotype and genotype of the infected abnormal B cells. Advances in treatment have improved outcomes, but mortality rates remain high. Our deepening understanding of KSHV biology, clinical features of KSHV-associated diseases, and newer clinical interventions should lead to improved and increasingly targeted therapeutic interventions.

Kidney biopsy findings in two patients with TAFRO syndrome: case presentations and review of the literature

Background

TAFRO syndrome is a clinical subtype of idiopathic multicentric Castleman disease (iMCD) that is characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis (or renal dysfunction), and organomegaly. TAFRO syndrome has only recently been described, and many clinicians are unaware of this disease, leading to delays in diagnosis and treatment. We present two patients with TAFRO syndrome in whom renal biopsies were performed.

Case presentation

Both patients had subacute onset and exhibited renal insufficiency, edema, anemia, thrombocytopenia, polyserositis and lymphadenopathy over the disease course. However, there were many differences in their clinical manifestations. Case 1 was a 30-year-old woman admitted due to intermittent vaginal bleeding for 3 weeks. Laboratory tests on admission showed severe renal insufficiency (creatinine: 624 μmol/L), severe anemia (Hb: 41 g/L), and moderate thrombocytopenia (61 × 10⁹/L). Case 2 was a 42-year-old man. Acute epigastric pain was his initial complaint, and computed tomography (CT) revealed retroperitoneal exudation around the pancreas. He was diagnosed with acute pancreatitis, and after treatment with a proton pump inhibitor (PPI) and somatostatin, his abdominal pain still recurred. During treatment, renal failure gradually increased, with oliguria, fever, anemia, thrombocytopenia, edema and massive ascites. Lymph node histologies were consistent with the hyaline-vascular (HV) type and mixed type, respectively, and renal histopathologies were consistent with thrombotic microangiopathy (TMA)-like renal lesions and membranoproliferative glomerulonephritis (MPGN), respectively. Their general conditions improved after glucocorticoid therapy, but their renal functions did not recover completely. On the basis of glucocorticoids, second-line treatments with tocilizumab and rituximab, respectively, were applied.

Conclusions

The diagnosis of TAFRO syndrome is based mainly on clinical manifestations and lymph node biopsies. A reliable early diagnosis and appropriate rapid treatment are essential to improve patient outcomes. Clinicians should deepen their understanding of this disease and similar conditions. Once the disease is suspected, lymph node biopsies should be performed as soon as possible. In addition, renal biopsies should be actively performed in patients with renal involvement.

Overview of Castleman disease

Castleman disease (CD) describes a group of at least 4 disorders that share a spectrum of characteristic histopathological features but have a wide range of etiologies, presentations, treatments, and outcomes. CD includes unicentric CD (UCD) and multicentric CD (MCD), the latter of which is divided into idiopathic MCD (iMCD), human herpes virus-8 (HHV8)-associated MCD (HHV8-MCD), and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD (POEMS-MCD). iMCD can be further subclassified into iMCD-thrombocytopenia, ascites, reticulin fibrosis, renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS). Advances in diagnosis, classification, pathogenesis, and therapy are substantial since the original description of UCD by Benjamin Castleman in 1954. The advent of effective retroviral therapy and use of rituximab in HHV8-MCD have improved outcomes in HHV8-MCD. Anti-interleukin-6-directed therapies are highly effective in many iMCD patients, but additional therapies are required for refractory cases. Much of the recent progress has been coordinated by the Castleman Disease Collaborative Network (CDCN), and further progress will be made by continued engagement of physicians, scientists, and patients. Progress can also be facilitated by encouraging patients to self-enroll in the CDCN's ACCELERATE natural history registry (#NCT02817997; www.CDCN.org/ACCELERATE).

[Idiopathic multicentric Castleman's disease]

Idiopathic multicentric Castlemans disease is a rare lymphoproliferative disorder that has many similar laboratory, radiological, clinical and pathological manifestations with various conditions, including IgG4-related disease. Increased activity of cytokines, especially interleukin-6, leads to systemic inflammatory symptoms with the development of lymphadenopathy and rarely extranodal lesions. Histological changes in the lymph nodesin hyaline vascular and plasma cell variants of Castlemans disease are hardly distinguishable from the pattern of reactive, tumor and IgG4-related lymphadenopathy. Idiopathic multicentric Castlemans disease can be diagnosed only when infection with human herpesvirus-8 type and human immunodeficiency virus is excluded. In the article, the authors describe two cases of idiopathic multicentric Castlemans disease, including the first world literature description of extranodal damage of the hip muscle in this disorder. In addition, the authors gave a review of the literature on the main clinical, laboratory and morphological manifestations, which allow confirming the diagnosis of Castlemans disease.

Is TAFRO syndrome a subtype of idiopathic multicentric Castleman disease?

Castleman disease (CD) is a rare lymphoproliferative disorder that can be unicentric or multicentric. Multicentric CD (MCD) is further subdivided into human herpesvirus type-8-associated, POEMS syndrome-associated, and idiopathic (iMCD). TAFRO syndrome is a newly identified disorder of unknown etiology characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly. The TAFRO syndrome is sometimes regarded as a subtype of iMCD (TAFRO-iMCD), whereas iMCD without TAFRO syndrome is considered "not otherwise specified" (iMCD-NOS). However, a proportion of patients with TAFRO syndrome have been diagnosed without lymph node biopsies (TAFRO syndrome without proven iMCD; TAFRO-w/op-iMCD). To clarify the clinical features of iMCD-NOS, TAFRO-iMCD, and TAFRO-w/op-iMCD, we retrospectively analyzed 220 patients extracted from the database of the Multicenter Collaborative Retrospective Study for Establishing the Concept of TAFRO Syndrome. The patients included 87 with iMCD-NOS, 63 with TAFRO-iMCD, and 19 with TAFRO-w/op-iMCD. Patients in all three groups exhibited anemia, hypoalbuminemia, and elevated serum C-reactive protein and interleukin-6 levels. No significant differences in clinical, laboratory, and prognostic features were noted between the TAFRO-iMCD, and TAFRO-w/op-iMCD groups. However, the iMCD-NOS group exhibited polyclonal hyper-γ-globulinemia. The five-year survival rates of patients in the iMCD-NOS and TAFRO-involved groups were 100% and 66.5%, respectively (dropping markedly during the first few months in the latter). The iMCD-NOS and the TAFRO-iMCD samples typically showed plasma cell and mixed-type histologies, respectively. Thus, iMCD can be classified into two distinct subtypes, iMCD-NOS and TAFRO-iMCD. As such, TAFRO-iMCD and TAFRO-w/op-iMCD may be considered the same entity, requiring prompt diagnosis and intensive care.

Osteosarcoma Manifesting Systemic Inflammation and Histological Features Mimicking Plasma Cell-type Castleman Disease

A 73-year-old man was referred to our hospital with a persistent fever, anemia, and a mass in the left pubic region. The findings of biopsy evaluations of the mass and a left inguinal lymph node were consistent with Castleman disease (CD) of plasma cell type. His serum interleukin 6 (IL-6) level was remarkably elevated, supporting the diagnosis of CD. However, imaging analyses revealed destruction of the pubic bone by the mass, which was atypical for CD. Therefore, another deeper biopsy was performed, which finally led to the diagnosis of IL-6-producing osteosarcoma. We conclude that clinicians should carefully exclude malignancies prior to making a CD diagnosis.

AIDS-Associated Malignancies

Malignancies were one of the earliest recognized manifestations that led to the description of the acquired immune deficiency syndrome (AIDS). The majority of cancers in AIDS patients are associated with coinfection with oncogenic viruses, such as Epstein-Barr virus, human herpesvirus 8, and human papillomavirus, with resulting malignancies occurring secondary to diminished immune surveillance against viruses and virus-infected tumor cells. Over 50% of AIDS lymphomas are associated with Epstein-Barr virus (EBV) and/or HHV8 infection. HHV8-associated diseases include Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). EBV is associated with several malignancies, including Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Coinfection with HIV and HPV is associated with an increased risk of various squamous cell carcinomas of epithelial tissues. HAART has significantly impacted the incidence, management, and prognosis of AIDS-related malignancies. In addition to changing the natural history of HIV infection in regard to incidence and survival, HAART has dramatically decreased the incidence of certain virally mediated HIV-associated malignancies such as KS and primary CNS lymphoma. The beneficial effects of HAART on these tumors are attributed to drug-mediated HIV suppression and immune reconstitution. However, HAART has had a less favorable impact on EBV- and HPV-related malignancies. This chapter presents an overview of HIV-associated malignancies mediated by HHV-8, EBV, and HPV, and reviews the effect of HAART on the epidemiology, presentation, treatment, and outcomes of these cancers.

International, evidence-based consensus treatment guidelines for idiopathic multicentric Castleman disease

Castleman disease (CD) describes a group of heterogeneous hematologic disorders with characteristic histopathological features. CD can present with unicentric or multicentric (MCD) regions of lymph node enlargement. Some cases of MCD are caused by human herpesvirus-8 (HHV-8), whereas others are HHV-8-negative/idiopathic (iMCD). Treatment of iMCD is challenging, and outcomes can be poor because no uniform treatment guidelines exist, few systematic studies have been conducted, and no agreed upon response criteria have been described. The purpose of this paper is to establish consensus, evidence-based treatment guidelines based on the severity of iMCD to improve outcomes. An international Working Group of 42 experts from 10 countries was convened by the Castleman Disease Collaborative Network to establish consensus guidelines for the management of iMCD based on published literature, review of treatment effectiveness for 344 cases, and expert opinion. The anti-interleukin-6 monoclonal antibody siltuximab (or tocilizumab, if siltuximab is not available) with or without corticosteroids is the preferred first-line therapy for iMCD. In the most severe cases, adjuvant combination chemotherapy is recommended. Additional agents are recommended, tailored by disease severity, as second- and third-line therapies for treatment failures. Response criteria were formulated to facilitate the evaluation of treatment failure or success. These guidelines should help treating physicians to stratify patients based on disease severity in order to select the best available therapeutic option. An international registry for patients with CD (ACCELERATE, #NCT02817997) was established in October 2016 to collect patient outcomes to increase the evidence base for selection of therapies in the future.

Kaposi's Sarcoma: A Clinico-Pathologic Overview

A careful overview of the classical appearances of Kaposi's sarcoma (KS) as well as of its variants were reviewed from the clinical and pathological point of view. The growth phases (stages) and the cellular patterns were histopathologically compared with emphasis on the developmental progression of disease as well as mitotic activity. Other morphological aspects were also assessed such as the features of the early phases and the incidence of hyaline bodies. One hundred and forty-three lesions from 96 patients mostly of the Italian sporadic type were investigated. A complete list of those entities which should be considered in differential diagnosis is shown and the dilemma of whether KS is a neoplasia or a hyperplasia is discussed.

Possible Association of Multicentric Castleman's Disease with Autoimmune Lymphoproliferative Syndrome

Multicentric Castleman's disease (MCD) is lymphoproliferative disorder characterized by systemic inflammatory symptoms such as fever and weight loss. Human herpes virus-8 (HHV-8) is thought to be a causable pathogen in all HIV-positive and some HIV-negative MCD patients. Furthermore, the term idiopathic MCD (iMCD) was recently proposed to represent a group of HIV-negative and HHV-8-negative patients with unknown etiologies. Although the international diagnostic criteria for iMCD require exclusion of infection-related disorders, autoimmune/autoinflammatory diseases and malignant/lymphoproliferative disorders to make an iMCD diagnosis, the relationships and differences between these disorders and MCD have not yet been clarified. We recently reported the first case of MCD with autoimmune lymphoproliferative syndrome (ALPS). Although ALPS was included in the iMCD exclusion criteria as an autoimmune/autoinflammatory disease according to the international diagnostic criteria, there is a lack of evidence on the association between MCD and ALPS. In this study, we review the recent understanding of MCD and discuss the possible association between MCD with ALPS.

Multicentric Castleman disease: Where are we now?

Multicentric Castleman disease (MCD) encompasses a spectrum of conditions that give rise to overlapping clinicopathological manifestations. The fundamental pathogenetic mechanism involves dysregulated cytokine activity that causes systemic inflammatory symptoms as well as lymphadenopathy. The histological changes in lymph nodes resemble in part the findings originally described in the unicentric forms Castleman disease, both hyaline vascular and plasma cell variants. In MCD caused by Kaposi sarcoma-associated herpesvirus/human herpesvirus-8 (KSHV/HHV8), the cytokine over activity is caused by viral products, which can also lead to atypical lymphoproliferations and potential progression to lymphoma. In cases negative for KSHV/HHV8, so-called idiopathic MCD, the hypercytokinemia can result from various mechanisms, which ultimately lead to different constellations of clinical presentations and varied pathology in lymphoid tissues. In this article, we review the evolving concepts and definitions of the various conditions under the eponym of Castleman disease, and summarize current knowledge regarding the histopathology and pathogenesis of lesions within the MCD spectrum.

Castleman's Disease and Interleukin 6

Castleman's disease is a rare condition characterized by benign hyperplastic lymph nodes. Based on the morphological features, it has been divided into hyaline-vascular, plasma cell and intermediate types. The latter two types are frequently associated with a wide variety of clinical pictures such as fever, anemia with hypotransferrinemia, hyperimmunoglobulinemia and an increase in the concentration of C-reactive protein (CRP). Although immunological disturbances have been suggested to play important roles in the pathophysiology of Castleman's disease, the precise mechanisms for the generation of its clinical pictures are still unsettled. In this respect, we have reported a pediatric case with spontaneous production of high levels of B cell differentiation factor (BCDF) activity by the hyperplastic lymph node, and we demonstrated here the strong expression of interleukin 6 (IL-6) gene in the lymph node cells. On the other hand, recent studies have revealed that IL-6 is a multifunctional cytokine; IL-6 not only induces the immunoglobulin production but also induces the acute phase reaction, and functions as an endogeneous pyrogen. In the acute phase reaction, IL-6 may induce an increase in CRP concentration and hypotransferrinemia. These studies indicate that the overproduction of IL-6 by the hyperplastic lymph node may be closely related to the pathophysiology of Castleman's disease. Therefore, it is considered that this disease is a "disorder of IL-6 production".

Idiopathic multicentric Castleman's disease: a systematic literature review

BACKGROUND

Multicentric Castleman's disease describes a group of poorly understood lymphoproliferative disorders driven by proinflammatory hypercytokinaemia. Patients have heterogeneous clinical features, characteristic lymph node histopathology, and often deadly multiple organ dysfunction. Human herpesvirus 8 (HHV8) causes multicentric Castleman's disease in immunosuppressed patients. The cause of HHV8-negative multicentric Castleman's disease is idiopathic; such cases are called idiopathic multicentric Castleman's disease. An absence of centralised information about idiopathic multicentric Castleman's disease represents a major challenge for clinicians and researchers. We aimed to characterise clinical features of, treatments for, and outcomes of idiopathic multicentric Castleman's disease.

METHODS

We did a systematic literature review and searched PubMed, the Cochrane database, and ClinicalTrials.gov from January, 1995, with keywords including "Castleman's disease" and "giant lymph node hyperplasia". Inclusion criteria were pathology-confirmed Castleman's disease in multiple nodes and minimum clinical and treatment information on individual patients. Patients with HHV8 or HIV infection or diseases known to cause Castleman-like histopathology were excluded.

FINDINGS

Our search identified 626 (33%) patients with HHV8-negative multicentric Castleman's disease from 1923 cases of multicentric Castleman's disease. 128 patients with idiopathic multicentric Castleman's disease met all inclusion criteria for the systematic review. Furthermore, aggregated data for 127 patients with idiopathic multicentric Castleman's disease were presented from clinical trials, which were excluded from primary analyses because patient-level data were not available. Clinical features of idiopathic multicentric Castleman's disease included multicentric lymphadenopathy (128/128), anaemia (79/91), elevated C-reactive protein (65/79), hypergammaglobulinaemia (63/82), hypoalbuminaemia (57/63), elevated interleukin 6 (57/63), hepatomegaly or splenomegaly (52/67), fever (33/64), oedema, ascites, anasarca, or a combination (29/37), elevated soluble interleukin 2 receptor (20/21), and elevated VEGF (16/20). First-line treatments for idiopathic multicentric Castleman's disease included corticosteroids (47/128 [37%]), cytotoxic chemotherapy (47/128 [37%]), and anti-interleukin 6 therapy (11/128 [9%]). 49 (42%) of 116 patients failed first-line therapy, 2-year survival was 88% (95% CI 81-95; 114 total patients, 12 events, 36 censored), and 27 (22%) of 121 patients died by the end of their observed follow-up (median 29 months [IQR 12-50]). 24 (19%) of 128 patients with idiopathic multicentric Castleman's disease had a diagnosis of a separate malignant disease, significantly higher than the frequency expected in age-matched controls (6%).

INTERPRETATION

Our systematic review provides comprehensive information about clinical features, treatment, and outcomes of idiopathic multicentric Castleman's disease, which accounts for at least 33% of all cases of multicentric Castleman's disease. Our findings will assist with prompt recognition, diagnostic criteria development, and effective management of the disease.

FUNDING

None.

Multicentric Castleman's Disease Associated with Inherited Epidermolysis Bullosa

Multicentric Castleman's disease (MCD) is a rare disorder characterized by fever, polyclonal hypergammaglobulinemia, and generalized lymphadenopathy. It has three histological characteristics: a recognizable architecture, germinal center abnormalities, and plasmacytosis. Inherited epidermolysis bullosa (EB) is also a rare disorder caused by a genetic defect. We report a 43-year-old patient with dystrophic EB, non-Hallopeau-Siemens recessive type or dominant type, displaying clinicopathologic features of MCD. In addition, his serum interleukin-6, which is thought to be responsible for the clinical symptoms in MCD, was elevated.

The great mimickers: Castleman disease

Castleman disease (CD) was first described and most commonly occurs in the form of classic hyaline-vascular-type CD with hyperenhancing localized (unicentric) nonneoplastic lymphadenopathy. CD may affect any body region including unusual locations for isolated lymph node enlargement. This makes CD a great mimicker of more common benign and malignant masses in the neck, chest, abdomen, and pelvis. CD masses commonly raise the suspicion of lymphoma, paraganglioma, neuroendocrine tumor, metastatic adenopathy, solid parenchymal tumors, and infectious or inflammatory diseases. The less common plasma cell-type CD, mixed CD, and human herpes virus-8-associated CD (HHV8-CD) are more prone to lead to generalized (multicentric) adenopathy without the typical nodal hyperenhancement and are associated with B symptoms and hematologic and immunologic manifestations. The generalized forms of CD have a worse prognosis, which can approach that of malignancies. CD has multiple known associations with neoplasms, skin diseases, blood dyscrasias, and immunodeficiency, which include certain forms of lymphoma; paraneoplastic pemphigus; polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome; and plasma cell dyscrasias. Cytokine overproduction (IL-6) is an important pathogenetic factor in the development of CD. The treatment is accordingly variable, from curative or diagnostic resection of a solitary lesion to systemic chemotherapy or anti-IL-6 therapy.

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.

Human herpesvirus 8-related Castleman disease in the absence of HIV infection

BACKGROUND

Castleman disease (CD) in the context of human immunodeficiency virus (HIV) infection is well described. It is almost always multicentric (MCD) and linked to human herpesvirus 8 (HHV-8). There are limited published data surrounding HHV-8-related CD among HIV-negative patients.

METHODS

From January 1995 through June 2012, we identified in a single center 18 HIV-seronegative patients with HHV-8-related CD. We report on their clinical, pathological, and laboratory features.

RESULTS

All cases were multicentric. Patients were aged 42-83 years and were referred with a relapsing remitting syndrome of fever (94%), constitutional symptoms (100%), peripheral lymphadenopathy (100%), splenomegaly (72%), hepatomegaly (50%), and edema (28%). Kaposi sarcoma was observed in 9 cases. Anemia and serum markers of inflammation were present in all cases. Polymerase chain reaction for HHV-8 DNA was positive on blood samples in all cases, whereas only 12 of 16 patients tested had positive HHV-8 serology at diagnosis. All cases showed the classic histological features of MCD, and LANA-1 immunostaining identified HHV-8-infected plasmablasts in 16 of 16 tested cases. Reactive hemophagocytic syndrome (44%), autoimmune hemolytic anemia (33%), and lymphoma (22%) were the commonest associated complications. Remission was obtained with etoposide in 13 of 15 cases. Rituximab allowed prolonged remission off therapy in 10 cases. Death occurred in 3 patients not treated with rituximab. These features were similar to those described in HIV-positive HHV-8-related MCD. Comparison between these 18 cases and 12 HIV-negative HHV-8-unrelated MCD cases showed marked discrepancies.

CONCLUSIONS

HHV-8-associated MCD may be considered as a single clinicopathological entity regardless of HIV status.

The clinical spectrum of Castleman's disease

Castleman's disease (CD) is a rare, poorly understood lymphoproliferative disease. The spectrum of symptoms and course of disease are broad, but there is no large study describing the natural history of this disease. Basic clinic and laboratory data from the records of 113 patients with CD evaluated at the Mayo Clinic and University of Nebraska were abstracted. The impact of these variables on overall survival (OS) from time of diagnosis was evaluated. Sixty patients had multicentric disease. Of the patients with multicentric CD, 32% had criteria sufficient for a diagnosis of POEMS syndrome. For all patients, 2, 5, and 10-year OS was 92%, 76%, 59%, respectively. Most of the factors identified as risk factors for death on univariate analysis cosegregated with diagnostic criteria for POEMS syndrome, which supported the concept of four categories of CD, which are (along with their 5-year OS): (1) unicentric CD (91%); (2) multicentric CD associated with the osteosclerotic variant of POEMS syndrome (90%); (3); multicentric CD without POEMS syndrome (65%); and (4) multicentric CD with POEMS syndrome without osteosclerotic lesions (27%). We have demonstrated that CD represents a spectrum of disease that can be differentiated by simple prognostic factors that provide a framework for further study.

Castleman disease

Castleman and Towne described a disease presenting as a mediastinal mass resembling thymoma. It is also known as "giant lymph node hyperplasia", "lymph node hamartoma", "angiofollicular mediastinal lymph node hyperplasia", and "angiomatous lymphoid hyperplasia". The pathogenesis is unknown, but the bulk of evidence points toward faulty immune regulation, resulting in excessive B-lymphocyte and plasma-cell proliferation in lymphatic tissue. In addition to the mediastinal presentation, extrathoracic involvement in the neck, axilla, mesentery, pelvis, pancreas, adrenal gland, and retroperitoneum also have been described. There are 2 major pathologic variations of Castleman disease: (1) hyaline-vascular variant, the most frequent, characterized by small hyaline-vascular follicles and capillary proliferation; and (2) the plasma-cell variant, in which large lymphoid follicles are separated by sheets of plasma cells. The hyaline-vascular cases usually are largely asymptomatic, whereas the less common plasma-cell variant may present with fever, anemia, weight loss, and night sweats, along with polyclonal hypergamma-globulinemia. Castleman disease is a rare lymphoproliferative disorders. Few cases have been described world widely. In this article we reviewed the classification, pathogenesis, pathology, radiological features and up to date treatment with special emphasis on the role of viral stimulation, recent therapeutic modalities and the HIV-associated disease.

HIV-associated multicentric Castleman disease

PURPOSE OF REVIEW

HIV-associated multicentric Castleman disease (HIV MCD) is a rare lymphoproliferative disorder, the incidence of which appears to be increasing in the highly active antiretroviral therapy era. Current knowledge of the disease is limited and this review will discuss what is known about the pathophysiology, diagnosis, management, and prognosis of HIV MCD.

RECENT FINDINGS

HIV MCD has been shown to be associated with infection with human herpesvirus-8. Vascular endothelial growth factor and the cytokine interleukin-6 (IL-6) are also thought to play a role in the pathogenesis of MCD. Currently, rituximab is often used alone or in combination with chemotherapy for treatment of MCD. Novel monoclonal antibodies targeting IL-6 and the IL-6 receptor are also being studied for the management of this disease.

SUMMARY

Because HIV MCD is an uncommon diagnosis, comprehensive clinical studies have not been done, and understanding of the disease is incomplete. Further studies are needed to make definitive conclusions regarding optimal treatment of HIV MCD.

Castleman's disease of the mesorectum: report of a case

Castleman's disease is a benign lymphoid proliferative disorder, which most commonly presents as a solitary mass in the mediastinum, although extrathoracic sites have been reported in the neck, axilla, pelvis, mesentery, pancreas, and retroperitoneum. We report a case of asymptomatic, isolated Castleman's disease in the mesorectum, which is extremely rare. The patient was a 34-year-old woman who underwent investigations for vaginal spotting. A presacral mass was located on the left side of the rectum, 10 cm from the anal verge. Contrast-enhanced computed tomography showed a large, well-demarcated, strongly enhancing mass with internal radiating septa in the mesorectum. The mass was well circumscribed and isointense to muscle on T1-weighted magnetic resonance imaging, appearing as a slightly hyperintense mass on T2-weighted imaging. We performed laparoscopic mesorectal mass excision, and histological examination revealed features typical of the hyaline-vascular type of Castleman's disease. Thus, when a mesorectal mass is being investigated, Castleman's disease should be considered in the differential diagnosis.

How I treat HIV-associated multicentric Castleman disease

HIV-associated plasmablastic multicentric Castleman disease is an increasingly frequent diagnosis. Kaposi sarcoma herpesvirus is found in the monotypic polyclonal plasmablasts that characterize this disease. Unlike Kaposi sarcoma, the incidence does not correlate with CD4 cell count or use of highly active antiretroviral therapy. It is a relapsing and remitting illness, and diagnostic criteria are emerging that define disease activity based on the presence of a fever and raised C-reactive protein coupled with a list of clinical features. Treatment protocols increasingly stratify therapy according to performance status and organ involvement. I advocate rituximab monotherapy for good performance status patients without organ involvement and rituximab with chemotherapy for more aggressive disease. The success of antiherpesvirus agents in controlling active disease is limited, but valganciclovir may have a role as maintenance therapy in the future.

A critical role of surgery in the treatment for paraneoplastic pemphigus caused by localized Castleman's disease

Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease associated with lymphoproliferative tumors, and sometimes with a very rare tumor, Castleman's disease (CD). PNP can present as a variety of dermatological diseases, and so far, only limited studies of PNP caused by CD have been reported, resulting in its higher possibility of misdiagnosis. Because of the variability of clinical presentation of PNP caused by CD, selection of the appropriate therapeutic approach remains unclear. To investigate the efficacy of surgery to patients with PNP caused by localized CD, the clinical, laboratory and pathological data of 5 patients with PNP caused by localized CD, 3 females and 2 males, aged 34 years (ranging from 29 to 42), with the tumor size from 6 x 4 x 4 cm(3) to 8 x 8 x 7 cm(3), located in the mediastinum (n = 3) and retroperitoneum (n = 2), were compared before and after surgery. All patients underwent surgery, and the diagnosis was confirmed by pathological examination. Surgery significantly improved mucosal lesions, cured skin lesions and decreased serum pemphigus autoantibody 6 months after surgery. Most patients were followed up for 6-48 months, and they all had no clinical or radiological recurrence and remain disease free. Therefore, surgery is an effective approach to cure patients with PNP caused by localized CD.

Castleman disease: an update on classification and the spectrum of associated lesions

Since its initial description, researchers have expanded the spectrum of Castleman disease to include not only the classic and well-recognized hyaline-vascular type, but also the plasma cell type and multicentric types of broader histologic range, including human herpes virus-8-associated Castleman disease. These less common subtypes of Castleman disease are less familiar, and may be under-recognized. Also of practical importance, current authors are restructuring the classification of multicentric Castleman disease to accommodate the emerging pathogenic role of human herpes virus-8 and its association with the recently described plasmablastic variant. In addition to an increased risk of lymphoma, patients with Castleman disease also are at increased risk for other related neoplasms, including Kaposi sarcoma and follicular dendritic cell tumors, which are of prognostic and therapeutic relevance. This review focuses on the histologic diagnosis of Castleman disease, current and emerging concepts in its pathogenesis and classification, and associated histopathologic entities.

Castleman's disease in the head of the pancreas: report of a rare clinical entity and current perspective on diagnosis, treatment, and outcome

BACKGROUND

Castleman's disease of the pancreas is a very rare condition that may resemble more common disease entities as well as pancreatic cancer.

CASE PRESENTATION

Here we report the case of a 58-year-old African American male with an incidentally discovered lesion in the head of the pancreas. The specimen from his pancreaticoduodectomy contained a protuberant, encapsulated mass, exhibiting microscopic features most consistent with localized/unicentric Castleman's disease. These included florid follicular hyperplasia with mantle/marginal zone hyperplasia along with focal progressive transformation of germinal centers admixed with involuted germinal centers.

CONCLUSION

To date, eight cases of Castleman's disease associated with the pancreas have been described in the world literature. We report the first case of unicentric disease situated within the head of the pancreas. In addition, we discuss the diagnostic dilemma Castleman's disease may present to the pancreatic surgeon and review current data on pathogenesis, treatment, and outcome.

Surgical outcome of superficial and deep Castleman disease

BACKGROUND

Castleman disease is a rare lymphoproliferative disease of low malignant potential occurring in two forms, unicentric and multicentric. Surgery, chemotherapy, immunotherapy and radiation therapy have all been used to manage the disease. In this study, we evaluate whether the site of the lesions, that is, superficial or deep, influences the surgical outcome.

METHODS

We retrospectively reviewed the records of 20 patients operated on for Castleman disease from 1994 to 2003, of whom 11 patients had superficial disease and 9 had deep lesions. The end-points of this study were survival and recurrence.

RESULTS

Of the 20 patients, 19 had unicentric (cervical in 8, mediastinal in 5, retroperitoneal in 2, axillary in 2, hepatic in 1, and mesenteric in 1) and 1 had multicentric Castleman disease. Among 19 patients who had complete resection (18 with unicentric and 1 with multicentric disease), there has been no evidence of recurrence.

CONCLUSION

Whether Castleman disease is superficial or deep has no effect on surgical outcome as long as resection is complete.

AIDS malignancies

Among individuals with HIV-infection, coinfection with oncogenic viruses including EBV, HHV-8, and HPV cause significant cancer-related morbidity and mortality. It is clear that these viruses interact with HIV in unique ways that predispose HIV-infected individuals to malignant diseases. In general, treatment directed specifically against these viruses does not appear to change the natural history of the malignant disease, and once the malignancy develops, if their health permits, HIV-infected patients should be treated using similar treatment protocols to HIV-negative patients. However, for the less frequent HIV-related malignancies, such as PEL, or MCD, optimal treatments are still emerging. For certain AIDS-defining malignancies, it is clear that the widespread access to HAART has significantly decreased the incidence, and improved outcomes. However, for other cancers, such as the HPV-related tumors, the role of HAART is much less clear. Further research into prevention and treatment of these oncogenic virally mediated AIDS-related malignancies is necessary.

Sarcoma Arising in Hyaline-Vascular Castleman Disease of Skin and Subcutis

We report on a case of a sarcoma arising in the hyaline-vascular variant of Castleman disease (HVCD) of the skin and subcutis. The patient was a 38-year-old man who clinically presented with a subcutaneous non-fixed cyst-like mass on his right shoulder with an unremarkable prior medical history. Histologic sections showed a biphasic tumor with numerous atretic lymphoid follicles located in the deep dermis and subcutis and a spindle-cell neoplasm mainly situated in the deep subcutis and adjacent soft tissue. The atretic lymphoid component fulfilled the criteria for HVCD, whereas the spindle-cell lesion showed all the criteria for sarcoma including nuclear atypia and frequent mitotic figures. The sarcomatous component was diffusely positive for fascin, nerve growth factor receptor, and CD34 with focal weak reactivity for CD21 and CNA.42. Stains for CD23, CD31, CD35, CD99, ALK-1, SMA, ASMA, desmin, factor XIIIa, AE1-AE3, EMA, bcl-2, S-100, Melan-A, HMB-45, Cam 5.2, and factor VIII were negative in the neoplastic spindle cells. No monoclonal population of lymphocytes was detected and we could not identify EBV or HHV-8 virus by PCR. Electron microscopy of the sarcomatous component showed spindle cells with labyrinth-like invaginations of the nucleus and numerous long, slender, interwoven cytoplasmic processes. The sarcomatous component in this case is most consistent with a poorly differentiated follicular dendritic cell sarcoma based upon the morphologic and ultrastructural findings.

Localized Castleman's Disease Presenting as a Vascular Right Iliac Fossa Mass

Castleman's disease is a rare lymphoproliferative disorder of unknown aetiology. The presentation is varied, diagnosis is difficult, and optimum management is still unknown. We report our experience with a case of Castleman's disease in a 34-year old woman who presented with pallor, hepatosplenomegaly, and a right iliac fossa mass that was 5 cm in diameter. this was initially diagnosed as a soft tissue sarcoma and preoperative tumour embolization was planned before excision. Mesenteric arteriogram revealed that the feeder arteries arose from the superior mesenteric artery and embolization was aborted for fear of causing bowel ischaemia. On laparotomy, lymphoid enlargement was found between the leaves of the jejunal mesentery. The tumour was relatively avascular and the overlying mesenteric vessels contributed to teh duplex ultrasound and computerized tomography appearance of hypervascularity. The tumour with the mesentery and the overlying segment of jejunum was excised completely. Histopathology confirmed Castleman's disease. The purpose of this report is to present this rare case that caused a diagnostic dilemma and to review the management of this disorder.

An unusual presentation of Castleman's disease:a case report

BACKGROUND

Castleman's disease (CD), a rare condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. We describe a patient with CD who presented with diffuse adenopathy involving the inguinal, paratracheal, retroperitoneal, axillary, and pelvic regions.

CASE PRESENTATION

Case report describing presentation, work-up, management and clinical course of a patient with Castleman's disease in the setting of a county hospital in metropolitan area. Patient was treated with chemotherapeutic agents.

CONCLUSIONS

To our knowledge, this represents the first case of CD involving an HIV-positive patient with a negative Human Herpes Virus (HHV-8) viral panel. Because patients with similar clinical histories are at high risk for the development of non-Hodgkin's lymphoma and Kaposi sarcoma, regular medical surveillance is recommended.

Castleman disease of the pleura: experience with eight surgically proven cases

BACKGROUND

Castleman disease of the pleura is unusual, and we present our experience with eight surgically proven cases.

METHODS

Between 1980 and 2002, 8 patients (7 women and 1 man; age range, 20 to 53 years; mean, 26.5 years) with surgically proven, pleural Castleman disease (six hyaline vascular type, one plasma cell type, and one mixed type) were encountered. Their clinical, imaging, and surgical findings were reviewed.

RESULTS

Five patients were asymptomatic, 1 had dyspnea, 1 had cough, and 1 experienced chest discomfort. Chest radiography showed a well-circumscribed interlobar, cardiophrenic, or paraaortic mass in 6 patients, a massive effusion in 1, and a focal diaphragmatic bulge in 1. Six tumors showed varying degrees of contrast enhancement (10 to 95 HU; mean, 46 HU) on computed tomography. Three cases appeared as well-defined, heterogeneously hyperintense pleural masses on magnetic resonance imaging. The masses varied in size from 3 to 10 cm (mean, 5.2 cm). Five masses greater than 5 cm had prominent pleural arterial blood supply and severe adhesions requiring thoracotomy and resection of nearby structures for radical tumor excision. Blood loss from patients varied between 100 and 850 mL (mean, 620 mL). No tumor recurrence was noted during follow-up (range, 1 to 16 years; mean, 6.5 years).

CONCLUSIONS

Pleural Castleman disease predominately affects young women and manifests as a well-circumscribed mass with a varying degree of contrast enhancement on computed tomography and heterogeneity on magnetic resonance imaging. Tumors greater than 5 cm have profuse pleural blood supplies and severe adhesion necessitating open thoracotomy and resection of neighboring structures. Radical resection can produce a satisfactory outcome.

Hyaline-vascular type Castleman's disease involving both orbits

PURPOSE

To describe a patient with hyaline-vascular type Castleman's disease (CD) whose initial examination revealed only upper eyelid mass. Further, to review all aspects of CD.

METHODS

Case report. An 18-year-old woman initially presented with swelling of both upper eyelids. She underwent an anterior orbitotomy with surgical excision followed by close observation.

RESULTS

Histopathological examination of the upper eyelid mass confirmed the presence of hyaline-vascular type CD. One year after surgical treatment, the patient is still asymptomatic, with no pathologic clinical or laboratory findings.

CONCLUSIONS

Castleman's disease is a rare but valid clinical entity. It should be considered in the differential diagnosis of asymptomatic orbital mass. Our understanding of CD has advanced recently. The treatment modalities for CD (e.g. surgical excision, radiation therapy and combination chemotherapy) are usually curative and optimizing. Castleman's disease involving the orbital area is now attracting ophthalmological interest.

Castleman's disease and spinal cord compression: case report

OBJECTIVE AND IMPORTANCE

Castleman's disease is a rare lymphoproliferative disorder most often found in the mediastinum. Localized forms are usually benign, whereas multicentric forms may be aggressive. We report a patient with Castleman's disease who presented with spinal cord compression, and we review previously published cases of Castleman's disease involving the central nervous system. To our knowledge, this is only the second case of Castleman's disease presenting as a spinal epidural mass with cord compression.

CLINICAL PRESENTATION

A 44-year-old otherwise healthy woman presented acutely with difficulty walking. Examination revealed mild myelopathy in her legs. Magnetic resonance imaging revealed a posterior epidural mass compressing the thoracic spinal cord at T3-T5.

INTERVENTION

Thoracic laminectomy and gross total resection of the lesion were performed. Pathological examination of the lesion identified the hyaline-vascular type of Castleman's disease. The patient's symptoms resolved postoperatively.

CONCLUSION

Castleman's disease presenting as a spinal epidural mass lesion with cord compression is rare. Surgical treatment can result in an excellent outcome.

Primary effusion lymphoma in HIV-infected patients with multicentric Castleman's disease

Multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL) are two B-cell lymphoproliferative diseases associated with Kaposi's sarcoma-associated herpes virus/human herpesvirus-8 (KSHV/HHV-8). Although MCD is considered a prelymphoma state, it is not known whether a pathogenetic link exists between MCD and PEL. This paper reports the clinico-pathological features of four cases of PEL (two pericardial, one pleural, and one peritoneal) developing in the context of HIV-associated MCD. Effusions, lymph nodes, spleen, and additional tissues from three autopsies were examined for morphology/immunophenotype, search for HHV-8 DNA, and assessment of immunoglobulin heavy chain gene (IgH) configuration using polymerase chain reaction (PCR)-based techniques. MCD and PEL samples contained HHV-8 DNA. Clonal IgH rearrangements were detected only in PEL, whereas MCD tissues were polyclonal. Light-chain immunostaining confirmed B-cell clonality in PEL (two lambda, one kappa, one not tested) and polyclonality in MCD. The autopsies revealed different morphological variants of visceral KS and multi-organ atypical infiltrates exhibiting immunoblastic/plasmablastic features reminiscent of PEL morphology, with a restriction of lambda-positive cells. In two cases, using microdissection and IgH PCR analysis, multiple/discrete bands were found in the infiltrates, compatible with polyclonality/oligoclonality. The case showing an oligoclonal IgH ladder contained a rearrangement of identical junctional size to the PEL clone; however, further analysis with PEL-derived clonotypic primers and sequencing of PCR products showed no amplification and nucleotide diversity, respectively, indicating that the two B-cell populations examined were clonally unrelated. These data show that MCD and PEL may co-exist in HIV-infected patients, suggesting a relevant association between these two HHV-8-related disorders. Although a definite clonal relationship between MCD and PEL was not demonstrated, it is hypothesized that in some MCD cases, within expanded polyclonal B-cell populations secondary to HHV-8 infection, clonal expansions may occur that localize into a body cavity, i.e. PEL.

Successful treatment of human immunodeficiency virus-related Castleman's disease with interferon-alpha

Multicentric Castleman's disease is an atypical lymphoproliferative disorder for which multiple chemotherapeutic regimens have been used without much success. Role of biological response modifiers like interferon used as a single agent is discussed in this case report.

Posttransplantation plasmacytic proliferations related to Kaposi's sarcoma-associated herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV), which was originally detected in Kaposi's sarcoma, also has been found in primary effusion lymphomas (PELs) and some cases of multicentric Castleman's disease. We describe two transplant recipients who developed Kaposi's sarcoma and a spectrum of non-neoplastic lymphoproliferative disorders that show pronounced plasmacytic and plasmacytoid features. The first patient had recurrent pleural effusions and Castleman's disease-like changes in lymph nodes. The second patient had systemic lymphadenopathy and hepatosplenomegaly secondary to diffuse infiltration by polyclonal plasma cells and plasmacytoid B lymphocytes that clinically mimicked Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease. In both cases, KSHV DNA was detected by polymerase chain reaction and Southern blotting, and KSHV vIL-6 protein expression was identified in affected tissues by immunohistochemical localization. In contrast, no evidence of KSHV coinfection was detected in any of 31 EBV-related posttransplant lymphoproliferative disorders or 112 non-PEL lymphomas tested. The pathologic findings in these two patients were not representative of malignancy by morphologic, immunophenotypic, or molecular criteria. This study underscores the marked propensity for hematolymphoid proliferations associated with KSHV infections to show plasmacytic features. Additionally, this study describes use of an antibody reactive against KSHV vIL-6 that can readily detect a subpopulation of KSHV-infected hematopoietic cells.

The management of unicentric and multicentric Castleman's disease: a report of 16 cases and a review of the literature

BACKGROUND

Castleman's disease (CD), or angiofollicular lymph node hyperplasia, creates both diagnostic and therapeutic dilemmas for most physicians. For patients with this rare and poorly understood disease, the optimal therapy is unknown. The authors report their experience during the years 1986-1997 with this uncommon clinicopathologic entity.

METHODS

Sixteen patients with a histologic diagnosis of CD were identified in the pathology database. Unicentric disease was defined as a solitary mass. Multicentric disease compromised patients with widespread lymphadenectomy. Clinical, radiologic, and laboratory data were analyzed to evaluate treatment response.

RESULTS

The study group consisted of 16 patients classified into 3 clinicopathologic groups: hyaline-vascular, plasma cell, and "mixed." Of those patients who underwent complete surgical excision of a unicentric hyaline-vascular CD mass (n = 8), all remain symptom free without clinical or radiographic recurrence. Two patients remain asymptomatic following partial resection or radiation therapy for an unresectable unicentric hyaline-vascular CD mass. Two patients with multicentric hyaline-vascular CD are currently in complete remission following adjuvant therapy. Multicentric plasma cell CD was present in a single patient. This patient (who underwent surgical and systemic therapy) died of disease within 4 months of presentation. Three patients with unicentric hyaline-vascular/plasma cell-CD remain symptom free following either complete resection or observation.

CONCLUSIONS

The authors recommend surgical resection for patients with the unicentric variant of CD. Surgical removal of a unicentric mass of hyaline-vascular or hyaline-vascular/plasma cell type is curative. Partial resection, radiotherapy, or observation alone may avoid the need for excessively aggressive therapy. Patients with multicentric disease, either hyaline-vascular or plasma cell type, do not benefit from surgical management and should be candidates for multimodality therapy, the nature of which has yet to be defined.