The clinical spectrum of Castleman's disease

The clinical picture of Castleman disease: a systematic review and meta-analysis

ABSTRACT

Castleman disease (CD) encompasses a spectrum of rare disorders, including unicentric CD (UCD), idiopathic multicentric CD (iMCD), and human herpesvirus 8-associated MCD (HHV8+ MCD). We performed a systematic review of publications reporting ≥5 cases of CD between 1995 and 2021, following preferred reporting items for systematic reviews and meta-analyses guidelines, to describe and compare subtypes. We extracted data on clinical symptoms and laboratory parameters as stated in international consensus diagnostic criteria for iMCD and estimated the frequency of each criterion using meta-analyses. We analyzed 32 studies describing 559 UCD, 1023 iMCD, and 416 HHV8+ MCD cases. Although many symptoms and laboratory abnormalities occurred at similar rates in patients with iMCD and HHV8+ MCD, patients with HHV8+ MCD had significantly higher rates of constitutional symptoms (46.6% vs 98.6%; P = .038) and splenomegaly (48.2% vs 89.2%; P = .031). Renal dysfunction was significantly more common in patients with iMCD than in patients with HHV8+ MCD before adjustment (36.9% vs 17.4%; P = .04; adjusted P = .1). Patients with UCD had lower rates of symptoms and laboratory abnormalities, although these were present in 20% of patients and were particularly pronounced in pediatric UCD. There are many similarities in the symptomatology of iMCD and HHV8+ MCD; many patients experience constitutional symptoms and organ dysfunction. Differences between these subtypes likely reflect differences in pathophysiology and/or comorbidity burdens.

Unexpected diagnosis of rare mesenteric Castleman disease: A case report and literature review

In this report, we present an Asian male patient who was 30 years old and admitted to the hospital due to pancreatitis. While undergoing a CT scan, an isolated mass was unexpectedly discovered in the patient's abdomen. The patient's abdominal pain, which was caused by pancreatitis, had resolved before he underwent surgical resection to remove the mass. Subsequently, the patient was diagnosed with Castleman disease based on pathology. Castleman disease occurring in the mesentery is exceptionally rare. Therefore, we have reviewed the essential information regarding Castleman disease and have found that the crucial part lies in the diagnosis and the consideration of distinct treatment strategies based on different types.

Longitudinal, natural history study reveals the disease burden of idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare hematologic disorder with heterogeneous presentations ranging from moderate constitutional symptoms to life-threatening multiorgan system involvement. There are vastly different clinical subtypes, with some patients demonstrating thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin fibrosis/renal failure, and organomegaly (TAFRO) and others having milder/more moderate symptoms with potential for severe disease (not otherwise specified, NOS). Due to its rarity and heterogeneity, the natural history and long-term burden of iMCD are poorly understood. We investigated real-world medical data from ACCELERATE, a large natural history registry of patients with Castleman disease, to better characterize the long-term disease burden experienced by these patients. We found that iMCD-TAFRO patients face a significant hospitalization burden, requiring more time in the hospital than iMCDNOS patients during the year surrounding diagnosis (median [interquartile range]: 36 [18-61] days vs. 0 [0-4] days; P<0.001). In addition, we found life-sustaining interventions, such as mechanical ventilation (17%) and dialysis (27%), were required among iMCD patients, predominantly those with iMCD-TAFRO. iMCD-NOS patients, however, spent a significantly greater proportion of time following disease onset in a state of disease flare (median 52.3% vs. 18.9%; P=0.004). Lastly, we observed severe iMCD-related morbidities, such as acute renal failure, sepsis and pneumonia, among others, arising after iMCD diagnosis, impairing the patients' quality of life. These data demonstrate a substantial disease burden experienced by iMCD patients and emphasize the importance of ongoing research into iMCD to aid disease control.

Increase in Vascular Endothelial Growth Factor (VEGF) Expression and the Pathogenesis of iMCD-TAFRO

TAFRO (thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (F/R), renal failure (R), and organomegaly (O)) is a heterogeneous clinical subtype of idiopathic multicentric Castleman disease (iMCD) associated with a significantly poorer prognosis than other subtypes of iMCD. TAFRO symptomatology can also be seen in pathological contexts outside of iMCD, but it is unclear if those cases should be considered representative of a different disease entity or simply a severe presentation of other infectious, malignant, and rheumatological diseases. While interleukin-6 (IL-6) is an established driver of iMCD-TAFRO pathogenesis in a subset of patients, the etiology is unknown. Recent case reports and literature reviews on TAFRO patients suggest that vascular endothelial growth factor (VEGF), and the interplay of VEGF and IL-6 in concert, rather than IL-6 as a single cytokine, may be drivers for iMCD-TAFRO pathophysiology, especially renal injury. In this review, we discuss the possible role of VEGF in the pathophysiology and clinical manifestations of iMCD-TAFRO. In particular, VEGF may be involved in iMCD-TAFRO pathology through its ability to activate RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathways. Further elucidating a role for the VEGF-IL-6 axis and additional disease drivers may shed light on therapeutic options for the treatment of TAFRO patients who do not respond to, or otherwise relapse following, treatment with IL-6 targeting drugs. This review investigates the potential role of VEGF in the pathophysiology of iMCD-TAFRO and the potential for targeting related signaling pathways in the future.

Update: The molecular spectrum of virus-associated high-grade B-cell non-Hodgkin lymphomas

The vast spectrum of aggressive B-cell non-Hodgkin neoplasms (B-NHL) encompasses several infrequent entities occurring in association with viral infections, posing diagnostic challenges for practitioners. In the emerging era of precision oncology, the molecular characterization of malignancies has acquired paramount significance. The pathophysiological comprehension of specific entities and the identification of targeted therapeutic options have seen rapid development. However, owing to their rarity, not all entities have undergone exhaustive molecular characterization. Considerable heterogeneity exists in the extant body of work, both in terms of employed methodologies and the scale of cases studied. Presently, therapeutic strategies are predominantly derived from observations in diffuse large B-cell lymphoma (DLBCL), the most prevalent subset of aggressive B-NHL. Ongoing investigations into the molecular profiles of these uncommon virus-associated entities are progressively facilitating a clearer distinction from DLBCL, ultimately paving the way towards individualized therapeutic approaches. This review consolidates the current molecular insights into aggressive and virus-associated B-NHL, taking into consideration the recently updated 5th edition of the WHO classification of hematolymphoid tumors (WHO-5HAEM) and the International Consensus Classification (ICC). Additionally, potential therapeutically targetable susceptibilities are highlighted, offering a comprehensive overview of the present scientific landscape in the field.

Idiopathic multicentric Castleman disease: An update in diagnosis and treatment advances

Idiopathic multicentric Castleman disease (iMCD) is a rare disease, and it is likely underdiagnosed because of the heterogeneity of clinical manifestations and laboratory findings. While the disease leads to significant morbidity and mortality, its causes are not yet fully elucidated. There have been significant advances in diagnosis and treatment of iMCD in the past decade, including the approval of the anti-IL-6 antibody siltuximab. In this review, we provide an update of the many new developments and publications surrounding iMCD.

Immune-mediated thrombocytopenia and IL-6-mediated thrombocytosis observed in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare haematological disorder characterized by generalized lymphadenopathy with atypical histopathological features and systemic inflammation caused by a cytokine storm involving interleukin-6 (IL-6). Three clinical subtypes are recognized: thrombocytopenia, anasarca, fever, renal dysfunction, organomegaly (iMCD-TAFRO); idiopathic plasmacytic lymphadenopathy (iMCD-IPL), involving thrombocytosis and hypergammaglobulinaemia; and iMCD-not otherwise specified (iMCD-NOS), which includes patients who do not meet criteria for the other subtypes. Disease pathogenesis is poorly understood, with potential involvement of infectious, clonal and/or autoimmune mechanisms. To better characterize iMCD clinicopathology and gain mechanistic insights into iMCD, we analysed complete blood counts, other clinical laboratory values and blood smear morphology among 63 iMCD patients grouped by clinical subtype. Patients with iMCD-TAFRO had large platelets, clinical severity associated with lower platelet counts and transfusion-resistant thrombocytopenia, similar to what is observed with immune-mediated destruction of platelets in immune thrombocytopenic purpura. Conversely, elevated platelet counts in iMCD-IPL were associated with elevated IL-6 and declined following anti-IL-6 therapy. Our data suggest that autoimmune mechanisms contribute to the thrombocytopenia in at least a portion of iMCD-TAFRO patients whereas IL-6 drives thrombocytosis in iMCD-IPL, and these mechanisms likely contribute to disease pathogenesis.

Retroperitoneal Castleman's disease in a young Nepalese girl: A rare cause of childhood abdominal mass

Introduction

Castleman's disease (CD), or benign angio-follicular lymph node hyperplasia, is an uncommon condition in childhood. When a child presents with a huge retroperitoneal mass and inconclusive findings on clinico-radiological evaluation or tissue sampling, management becomes exceedingly difficult. CD herein becomes an uncommon presentation of an uncommon diagnosis.

Case presentation

A six-year-old girl with no past medical problems presented to the office with a slowly progressive, painless mass over the right lumbar region for a year. Abdominal ultrasound showed a well-defined oval mass in the right periumbilical region, further evaluation of which with a computed tomography scan suggested lymphoma. A preoperative core-cut biopsy could not confirm the findings and suggested a neoplastic lesion, probably an inflammatory myofibroblastic tumour or small round cell tumour. She underwent an exploratory laparotomy with in-toto excision of the mass. Intraoperatively, a solid retroperitoneal tumour measuring 8×8×6 cm was found. Histopathology and immunohistochemistry confirmed a unicentric CD of the hyaline-vascular type. At two years of follow-up, she remained asymptomatic and disease-free.

Conclusion

While CD in children is rare, retroperitoneal localization of the same can further add to the diagnostic conundrum. However, if carefully considered, an en-bloc surgical resection offers complete treatment.

Retrospective cohort evaluation of non-HIV Castleman disease from a single academic center in Beijing, China

The purpose is to ascertain the clinical impact of Castleman disease (CD) by reassessment of the real-world data from Peking University First Hospital (PKUFH). The results will contribute to the standardization of diagnosis and treatment on CDs. Based on the last 15-year retrospective real-world data from Peking University First Hospital (PKUFH), we reclassified and re-evaluated the clinical and pathological information of patients with pathologically suspected diagnosis of CD. A total of 203 patients were included in our study, in which the diagnosis of CD was confirmed in 189 cases, including 118 patients with unicentric CD (UCD, n = 118, 62.4%) and 71 patients with multicentric CD (MCD, n = 71, 37.6%). A total of 44.1% (n = 52) of UCDs in our cohort were complicated with paraneoplastic pemphigus (PNP). The treatment of UCD is primarily surgical, with a 5-year overall survival (OS) of 88.1%. Patients with PNP had a poorer prognosis than those without PNP (82.9% (95% CI 123-178) vs 92.8% (95% CI 168-196), log-rank p = 0.041). The rate of concurrent systemic symptoms was 74.6% (n = 53), and renal involvement occurred in 49.3% (n = 35) MCD patients. The MCD treatments were mainly chemotherapy regimens, with a 5-year OS of 77.6% (95% CI, 143-213). Patients with UCD demonstrate a better overall prognosis than patients with MCD. But the prognosis of those complicated with PNP was poor. The differential diagnosis of MCD is extensive. MCD treatment in China is heterogeneous. The inaccessibility of anti-IL-6-targeted drugs in China may contribute to the poor prognosis for patients with MCD.A preprint has previously been published (Guo et al. 34).

Castleman disease: Experience from a single institution

Castleman disease (CD) describes a group of rare heterogeneous lymphoproliferative disorders characterized by enlarged hyperplastic lymph nodes. It is classified into unicentric CD (UCD) and multicentric CD (MCD). The present retrospective study examined the data of 11 patients with CD diagnosed and treated at a tertiary cancer center from 2017 to 2022. The median age of the study group was 41 years (range, 24 to 68 years). There were 8 males and 3 females. In total, 7 patients were diagnosed with UCD and 4 patients with MCD. The hyaline-vascular variant was the most common histology in both UCD and MCD. Among the 7 patients with UCD, 5 patients underwent excision, 1 patient underwent debulking followed by radiotherapy and 1 patient received single agent rituximab. Of the patients with UCD, 6 had a complete response (CR) and 1 patient had a partial response (PR). All 4 patients with MCD received systemic treatment, which included single agent rituximab (2 patients), rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (RCHOP) (1 patient) and CHOP (1 patient). Among the patients with MCD, 1 patient attained a CR, 2 patients had a PR and 1 patient succumbed. The 3-year survival rate for the study population was 91%. In summary, CD is a rare disease occurring in immunodeficient patients. UCD is more common and is associated with better outcomes. Surgery is the mainstay of management in UCD whereas MCD requires combination chemotherapy.

POEMS syndrome in the 21st century: A bibliometric analysis

Background

POEMS syndrome is a rare and complex plasma cell disorder characterized by polyneuropathy, organomegaly, endocrinopathy, high M protein levels, and skin changes. Understanding of POEMS syndrome has advanced rapidly since the 21st century. This study aims to summarize and evaluate the research status of POEMS syndrome in the past 23 years through a bibliometric and visualization analysis, and identify research focuses and emerging hotspots for the future.

Methods

POEMS syndrome-related articles published between January 1, 2000, and March 8, 2023, were systematically retrieved from the Web of Science Core Collection. Data processing and visualization analysis were carried out using a combination of R software, HistCite, VOSviewer, and CiteSpace.

Results

Since entering the 21st century, 3677 authors from 1125 institutions in 68 countries/regions have published 830 original and review articles on POEMS syndrome in 408 journals so far, among which the USA, Japan, and China published the most articles, and Mayo Clinic, Udice French Research Universities, and Peking Union Medical College listed the top three most prolific institutions. However, collaborative research across countries and groups in the study of POEMS syndrome remain significantly limited. Angela Dispenzieri ranked first in POEMS syndrome research from every aspect of authors, producing the most papers and contributing the most-cited article, followed by Satoshi Kuwabara and Sonoko Misawa. Internal medicine was the most productive journal on POEMS syndrome. "endothelial growth factor" was the keyword with the highest occurrence except for "POEMS syndrome", and "bevacizumab", "lenalidomide", "dexamethasone", and "management" were recognized as emerging topics.

Conclusion

This study utilized bibliometric and visualization analysis to systematically summarize the research of POEMS syndrome in the first two decades of the 21st century, offering a data-based and objective perspective on the field of POEMS syndrome and guiding researchers in the identification of novel research directions.

Classical Hodgkin Lymphoma on the Background of Castleman Disease: A Case Report

Castleman disease (CD) is a rare lymphoproliferative disorder that is associated with an increased risk for lymphoma. The association between CD and classical Hodgkin lymphoma (HL) is rare. The patient described here is a 44-year-old, HIV-seronegative male who presented with significant weight loss, fever, night sweats, and right axillary swelling. Imaging showed bulky infraclavicular, subpectoral, and axillary lymph nodes. A biopsy revealed classical HL on the background of a human herpesvirus-8 (HHV-8)-negative plasma cell variant of CD. The patient had a complete remission after six cycles of doxorubicin, bleomycin, vincristine, and dacarbazine (ABVD) that were followed by consolidative radiotherapy and continued to be disease-free for more than two years.

Cost-Effectiveness Analysis of Siltuximab for Australian Public Investment in the Rare Condition Idiopathic Multicentric Castleman Disease

OBJECTIVES

This paper presents an Australian model that formed part of the health technology assessment for public investment in siltuximab for the rare condition of idiopathic Multicentric Castleman Disease (iMCD) in Australia.

METHODS

Two literature reviews were conducted to identify the appropriate comparator and model structure. Survival gain based on available clinical trial data were modelled using an Excel-based model semi-Markov model including time-varying transition probabilities, an adjustment for trial crossover and long-term data. A 20-year horizon was taken, and an Australian healthcare system perspective was adopted, with both benefits and costs discounted at 5%. The model was informed with an inclusive stakeholder approach that included a review of the model by an independent economist, Australian clinical expert opinion and feedback from the Pharmaceutical Benefits Advisory Committee (PBAC). The price used in the economic evaluation reflects a confidential discounted price, which was agreed to with the PBAC.

RESULTS

An incremental cost-effectiveness ratio of A$84,935 per quality-adjusted life-year (QALY) gained was estimated. At a willingness-to-pay threshold of A$100,000 per QALY, siltuximab has a 72.1% probability of being cost-effective compared with placebo and best supportive care. Sensitivity analyses results were most sensitive to the length of interval between administrations (from 3- to 6-weekly) and crossover adjustments.

CONCLUSION

Within a collaborative and inclusive stakeholder framework, the model submitted to the Australian PBAC found siltuximab to be cost-effective for the treatment of iMCD.

Evolution of Pulmonary Involvement in Idiopathic Multicentric Castleman Disease-Not Otherwise Specified: From Nodules to Cysts or Consolidation

BACKGROUND

Previous studies about multicentric Castleman disease-associated pulmonary manifestations have been limited by small cohorts and not following the Castleman Disease Collaborative Network classification criteria of multicentric Castleman disease. The pulmonary manifestations in idiopathic multicentric Castleman disease-not otherwise specified (iMCD-NOS), a distinct clinical phenotype in the classification criteria, have not been reported.

RESEARCH QUESTION

Which pulmonary abnormalities in iMCD-NOS are advanced manifestations and which are reversible after effective treatment?

STUDY DESIGN AND METHODS

Patients diagnosed with iMCD-NOS with pulmonary involvement were enrolled. The baseline CT scan was evaluated for the presence and anatomic locations of pulmonary abnormalities. Patients were further divided into different subgroups according to baseline CT scan manifestations. Follow-up CT scan was reviewed to assess the changes in pulmonary lesions among patients without and with treatment.

RESULTS

Of 162 patients with iMCD-NOS, 58 individuals (35.8%) with pulmonary involvement were identified. Pulmonary manifestations included nodules (96.6%), cysts (65.5%), consolidation (22.4%), interstitial thickening (50.0%-87.9%), and ground-glass opacities (55.2%). Patients (n = 58) were further classified into nodule (n = 15), cyst (n = 33), and consolidation (n = 10) subgroups. Patients in the consolidation (median, 67 months) and cyst (median, 23 months) subgroups had a longer duration of symptoms before the baseline CT examination than those in the nodule subgroup (median, 12 months) (P = .016). During follow-up, the evolution of pulmonary lesions from nodules to cysts was observed in two patients without treatment. After treatment, pulmonary lesions, except for cysts, improved in most patients. Moreover, nodules or cysts progressed into consolidation in two patients.

INTERPRETATION

Pulmonary involvement is not rare in iMCD-NOS. Chest CT scan examination is very essential in finding potential pulmonary abnormalities. Pulmonary manifestations follow a unique pattern with evolution from nodules to cysts or consolidation, the latter of which can also form in cystic areas. Timely diagnosis of pulmonary involvement is crucial because of possible reversibility after treatment.

Unicentric form of Castleman´s disease, pitfalls of diagnosis and surgical treatment

Background

Castleman´s disease is an extremely rare heterogenous lymphoproliferative pathology with a mostly benign behavior. It is a localized or generalized lymph node enlargement of an unknown aetiology. Unicentric form is typically a slow-growing solitary mass occurring mostly in the mediastinum, abdominal cavity, retroperitoneum, pelvis and neck. Aetiology and pathogenesis of CD is probably diverse, varying in different types of this heterogeneous disease.

Materials and Methods

Authors present a review of this issue based on their extensive experience. The aim is to summarize the crucial factors in the management of diagnostics and a surgical treatment of the unicentric form of Castleman´s disease. One of the key issues in the unicentric form is precise preoperative diagnostics and thus choosing the right surgical treatment strategy. Authors highlight pitfalls of the diagnosis and surgical treatment.

Results

All histological types such as a hyaline vascular type, plasmacytic type and a mixed type are presented as well as options of surgical and conservative treatment. Differential diagnosis and malignant potential is discussed.

Conclusion

Patients with Castleman´s disease should be treated in the high- volume centers, with a great experience in major surgical procedures as well as with preoperative imaging diagnostic techniques. Specialized pathologists and oncologists focusing on this issue are also absolutely necessary to avoid misdiagnosis. Only this complex approach can lead to excellent outcomes in patients with UCD.

18F-FDG PET/CT and contrast-enhanced CT in the diagnosis of Castleman disease

OBJECTIVE

Castleman disease (CD) is a rare group of lymphoproliferative disorders, which is easily confused with lymphoma or other solid tumors. Hence, this study aimed to investigate the diagnostic role of ¹⁸F-FDG PET/CT and contrast-enhanced CT (CECT) in patients with CD.

METHODS

Clinicopathological characteristics, and ¹⁸F-FDG PET/CT and CECT findings and parameters were retrospectively reviewed in 32 patients with CD.

RESULTS

These 32 patients (12 males, 20 females; median age, 41 years) consisted of 17 unicentric CD (UCD) patients and 15 multicentric CD (MCD) patients. Compared with MCD, UCD had a higher prevalence in female (82.4% vs. 40.0%) and hyaline vascular subtype (94.1% vs. 40.0%) (P < 0.05). FDG uptake was avid in all cases, including moderate uptake in 7 cases and intense uptake in 25 cases. The median SUVmax, SUVmean, MLV, and TLG of all cases were 4.4 (range, 1.4-23.6), 2.7 (range, 1.1-15.2), 26.6 (range, 4.8-393.0), and 78.8 (range, 9.4-1545.6), respectively. The lesions of 29 cases showed homogeneous enhancement, and marked enhancement was observed in 27 cases. ¹⁸F-FDG PET/CT corrected 6.3% CECT diagnoses, while CECT corrected 37.5% PET/CT diagnosis. The accuracy of combined PET/CT and CECT was superior to PET/CT or CECT alone (78.1%, 31.3%, and 62.5%). Besides, higher SUVmax and SUVmean were found in male subjects, MCD, and plasma cell subtype (P < 0.05), while higher MLV and TLG were observed in larger lesion size and volume (P < 0.05).

CONCLUSION

Castleman disease most commonly appears as marked and homogeneous enhancement meanwhile with moderate or intense FDG uptake. ¹⁸F-FDG PET/CT combined with CECT was the effectively diagnostic modality for CD. The glucose metabolism of CD was associated with gender, clinical classification, histopathological classification, and lesion size and volume.

A Case of Castleman's Disease during the Long-Term Course of Membranous Nephropathy

Concomitant with nephrotic syndrome and multicentric castleman's disease (MCD) has only been described in a limited number of small studies and case reports. Among those, none confirmed the renal pathology prior to the onset of MCD, and none of the cases had a history of nephrotic syndrome. A 76 year-old Japanese man visited a nephrologist because of incident nephrotic syndrome. He had previously experienced three episodes of nephrotic syndrome, the last one 13 years ago, and had been diagnosed with membranous nephropathy by renal biopsy. Apart from these previous episodes, he also suffered from systemic lymphadenopathy, anemia, elevated C-reactive protein, polyclonal hypergammopathy, and elevated interleukin (IL)-6. An inguinal lymph node biopsy revealed CD138-positive plasma cells in the interfollicular region. Based on these findings, MCD was diagnosed. Renal biopsy indicated primary membranous nephropathy with spike lesions and bubbling in the basement membranes and deposition of immunoglobulin (Ig) G, IgA, IgM, and phospholipase A2 receptor along the glomerular basement membrane. Corticosteroid monotherapy successfully reduced the edema, proteinuria, and IL-6, but hypoalbuminemia was not sufficiently improved due to castleman's disease and remission of the nephrotic syndrome was not achieved. Later, tocilizumab was administered for remission induction in another facility. To the best of our knowledge, this represents the first report of Castleman's disease with previously diagnosed membranous nephropathy. This case does not provide a causal mechanism for the pathophysiology, but it may be worth suggesting possible involvement of MCD as a trigger for recurrence of membranous nephropathy.

Glucocorticoids combined with tofacitinib in the treatment of Castleman's disease: A case report

BACKGROUND

Castleman's disease (CD), also known as vascular follicular lymphadenopathy is a rare proliferative disease of lymphoid tissue of unknown etiology that is clinically classified as unicentric CD (UCD) or multicentric CD (MCD) depending on lymph node involvement. At present, idiopathic MCD (iMCD) is treated with interleukin-6 inhibitors, but some patients have poor clinical outcomes. This paper reports on a case of iMCD that achieved a good therapeutic effect after treatment with glucocorticoids combined with tofacitinib. The relevant data are summarized and reported below.

CASE SUMMARY

This paper reports on a case of MCD in a 49-year-old female with persistent peritoneal effusion as the first manifestation and combined with multiple lymphadenopathies. Lymph node biopsy showed Castleman's disease-like changes. The ascites subsided after treatment with glucocorticoids and tofacitinib, indicating that the treatment was effective.

CONCLUSION

The combination of glucocorticoids with tofacitinib is an effective regimen for the treatment of CD.

Multicentric Castleman Disease: The Hyaline Vascular Type Without HIV Association in a Young Male With Cutaneous Manifestation and Renal Impairment

Castleman disease (CD), a heterogenous lymphoproliferative disorder resulting from immune dysregulation, is a very rare disease in clinical practice. The clinical spectrum of Castleman disease is wide and its treatment options are mostly based on case reports and case series. To date, two clinical and four histological types have been described. It has recently been successfully demonstrated that the pathogenesis of multicentric Castleman disease (MCD) has a direct association with human immunodeficiency virus (HIV) and human herpes virus 8 (HHV-8) infection which is why further studies are necessary. Here, we report an unusual case of MCD not associated with HIV and having a histological diagnosis of the hyaline vascular type that presented with acute renal impairment and subcutaneous abnormal lymphatic proliferation.

Siltuximab is associated with improved progression-free survival in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare, heterogeneous disorder involving multicentric lymphadenopathy, systemic inflammation, and cytokine-driven organ dysfunction. Despite the approval of siltuximab-a monoclonal antibody against interleukin-6-for the treatment of iMCD, it is not known how long patients should receive siltuximab before determining whether the treatment is beneficial and should be continued. We performed post hoc analyses of the phase 2 randomized, double-blind, placebo-controlled trial of siltuximab for the treatment of patients with iMCD (NCT01024036) to determine the sequence of normalization of laboratory, clinical, and lymph node responses in patients who responded to siltuximab. Seventy-nine patients were enrolled in the trial (n=53 siltuximab; n=26 placebo plus best supportive care). Progression-free survival (PFS) was significantly improved in siltuximab-treated patients compared with placebo (P=0.0001). The median PFS was 14.5 months (95% CI, 13.6-upper bound not reached) for patients on placebo, but not reached for patients on siltuximab. In siltuximab-treated patients who achieved a durable tumor (radiologic) and symptomatic response (18/53 [34%]), the median time to normalization of abnormal laboratory tests and clinical endpoints occurred in the following sequence: thrombocytosis, symptomatic response, elevated C-reactive protein, hypoalbuminemia, anemia, lymph node response, hyperfibrinogenemia, and elevated immunoglobulin G. Siltuximab treatment prolongs PFS, rapidly improves symptomatology, and provides meaningful clinical benefit despite some laboratory tests and enlarged lymph nodes taking months to normalize in treatment responders. These data support the continued front-line use of siltuximab for iMCD, as recommended by international guidelines.

Efficacy and Safety of Regimens Used for the Treatment of Multicentric Castleman Disease: A Systematic Review

OBJECTIVES

Treatment options for multicentric Castleman disease (MCD) remain limited. The only FDA-approved drug is siltuximab for idiopathic MCD (iMCD), but the response rate with siltuximab is less than 50%. We performed a systematic review to examine the efficacy and safety of various regimens used for the treatment of MCD.

METHODS

A database search on PubMed, Embase, Cochrane, Web of Science, and Clinicaltrials.gov using the terms "Castleman disease," "treatment outcome" and "patient safety" was done.

RESULTS AND CONCLUSIONS

Results from a randomized controlled trial (RCT) and an extension study highlighted the efficacy and long-term safety of siltuximab for iMCD; other trials showed tocilizumab to be a suitable alternative. A recent trial reported high response rates with thalidomide in iMCD patients. Promising results were reported for bortezomib in relapsed/ refractory MCD. For human herpesvirus 8 (HHV-8) associated MCD, rituximab along with doxorubicin therapy followed by maintenance with zidovudine and valganciclovir is the most effective therapy. A single-arm trial has highlighted the potential role of tocilizumab in HHV-8 MCD. Data for these regimens are limited and mostly comprise non-randomized trials. Further research on emerging agents could have a major impact on the treatment of this rare disease.

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.

Clinical and Molecular Characteristics of 60 Patients With Human Immunodeficiency Virus-Negative Castleman Disease

Castleman disease (CD) is a rare lymphoproliferative disorder. The mechanistic target of rapamycin (mTOR) pathway is a key regulator of various cellular functions, which may be related with the potential mechanisms of CD occurrence. We retrospectively collected the clinical information of 60 CD patients diagnosed in the First Affiliated Hospital of Zhengzhou University. And FFPE biopsy specimens were collected from 31 patients (12 unicentric CD patients and 19 multicentric CD patients) to detect the mTOR pathway protein expression. We are the first to demonstrate that thrombocytopenia and hypoalbuminemia are independent poor prognostic factors for CD. Moreover, mTOR activation was higher in CD compared to reactive lymphoid hyperplasia (used as a control group). This study offers some elucidation for the management and treatment of CD patients.

Comprehensive analysis of 65 patients with Castleman disease in a single center in China

This study aimed to investigate the epidemiologic, clinical, pathological characteristics, and treatment of patients with Castleman disease (CD) in a single center in China. We retrospectively analyzed the data of 65 Chinese CD patients, divided into unicentric CD (UCD) and multicentric CD (MCD) groups, and also microscopic subtypes as hypervascular (HV), plasmacytic (PC) and Mixed. Based on whether HHV-8 infection existed, MCD was subdivided into HHV-8-associated MCD and idiopathic Castleman disease (iMCD). Detailed epidemiologic, clinicopathological, and treatment data were analyzed and discussed. Of total 65 patients (UCD 33, MCD 32), HV (81.8%) accounted for the most of UCD and total. More females in UCD (60.6%) and more males in MCD (65.6%) were observed. CD occurred in all age groups, most commonly in 40-49 years. The mean age of onset of total was 38.5 years with PC higher than HV (45.5 vs. 35.1 years, P = 0.0413). The median diagnosis delay of MCD was longer than that of UCD (3.00 vs. 1.25 months, P = 0.0436). Abdomen (39.4%) and neck (30.3%) were the most-seen locations of lymphadenopathy in UCD, with neck (65.6%) being predominant in MCD. Mean major diameter of specimens of UCD was greater than MCD (6.4 vs. 3.1 cm, P < 0.0001). These results provided the featured and detailed profile of Castleman disease in Henan province in China with a considerable number of cases, which presented distinct evidence with other studies.

The disease course of Castleman disease patients with fatal outcomes in the ACCELERATE registry

Castleman disease (CD) describes a group of rare, potentially fatal lymphoproliferative disorders. To determine factors associated with mortality in CD, we analysed data from deceased patients in the ACCELERATE registry and compared them with matched controls. We analysed demographic, treatment and laboratory data from all deceased CD patients, matched controls and a subgroup of idiopathic multicentric Castleman disease (iMCD) patients. Of the 140 patients in ACCELERATE with a confirmed CD diagnosis, 10 had died. There were 72 patients with confirmed iMCD; six were deceased. The deceased CD cohort had more hospitalisations per year, higher overall hospitalisations and more days hospitalised per month, and received more treatment regimens per year than the matched‐control group. Analysis of laboratory values showed a significantly decreased absolute lymphocyte count at months 3 and 6 in the deceased cohort compared with controls. Among iMCD patients, there was a higher proportion of iMCD‐TAFRO (thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction and organomegaly) cases in the deceased group. The deceased iMCD group had significantly lower immunoglobulin M, international normalised ratio and platelet count. These data demonstrate that there may be differences between patients who have fatal and non‐fatal outcomes, and provide preliminary suggestions for parameters to evaluate further.

Multicentric Castleman disease: A single center experience of treatment with a focus on autologous stem cell transplantation

Castleman disease (CD) is a rare lymphoproliferative disease characterized by diverse clinical and pathologic features. Due to its rarity, there are limited studies comparing currently available therapies. The role of autologous stem cell transplantation (ASCT) in CD has not yet been established. In this paper, we describe the clinical characteristics, treatment choices, and outcomes in 34 Mayo Clinic patients diagnosed with multicentric CD from July 1, 2003 to April 30, 2018. Eighteen patients (53%) also met the criteria for POEMS, including 14 with the osteosclerotic variant. The first-line treatments included: steroid monotherapy (4), cytotoxic chemotherapy (6), rituximab alone (8) or with chemotherapy (2), anti-IL6 treatment (3), and ASCT (10). The median follow-up was 4.8 (range: 0.1-15.2) years. The 5- and 10-year overall survival rates were 84% and 71%, respectively. Sixteen patients received high-dose chemotherapy followed by ASCT during their disease course. Among those, 14 had multicentric CD associated with POEMS. There were no transplant-related deaths. All patients had at least a partial response to ASCT, most of whom achieved a complete response. The favorable outcomes seen with ASCT in this cohort suggest that transplantation may have a role in multicentric CD, particularly for patients with multicentric CD associated with POEMS.

Transcriptome and unique cytokine microenvironment of Castleman disease

Castleman disease (CD) represents a group of rare, heterogeneous and poorly understood disorders that share characteristic histopathological features. Unicentric CD (UCD) typically involves a single enlarged lymph node whereas multicentric CD (MCD) involves multiple lymph node stations. To understand the cellular basis of CD, we undertook a multi-platform analysis using targeted RNA sequencing, RNA in-situ hybridization (ISH), and adaptive immune receptor rearrangements (AIRR) profiling of archived tissue from 26 UCD, 14 MCD, and 31 non-CD reactive controls. UCD showed differential expression and upregulation of follicular dendritic cell markers (CXCL13, clusterin), angiogenesis factors (LPL, DLL4), extracellular matrix remodeling factors (TGFβ, SKIL, LOXL1, IL-1β, ADAM33, CLEC4A), complement components (C3, CR2) and germinal center activation markers (ZDHHC2 and BLK) compared to controls. MCD showed upregulation of IL-6 (IL-6ST, OSMR and LIFR), IL-2, plasma cell differentiation (XBP1), FDC marker (CXCL13, clusterin), fibroblastic reticular cell cytokine (CCL21), angiogenesis factor (VEGF), and mTORC1 pathway genes compared to UCD and controls. ISH studies demonstrated that VEGF was increased in the follicular dendritic cell-predominant atretic follicles and the interfollicular macrophages of MCD compared to UCD and controls. IL-6 expression was higher along interfollicular vasculature-associated cells of MCD. Immune repertoire analysis revealed oligoclonal expansions of T-cell populations in MCD cases (2/6) and UCD cases (1/9) that are consistent with antigen-driven T cell activation. The findings highlight the unique genes, pathways and cell types involved in UCD and MCD. We identify potential novel targets in CD that may be harnessed for therapeutics.

Siltuximab-Related Favorable Clinical Outcome for a Patient Suffering from Idiopathic Multicentric Castleman Disease

RationalCastleman disease is a rare lymphoproliferative disorder that can be subdivided into unicentric and multicentric forms, the latter of which causes a spectrum of serious medical conditions. Here, we present a case of idiopathic multicentric Castleman disease in the eighth decade of life. Patient Concerns. First hospitalized due to unexplained progressive anemia, the patient was readmitted to the hospital 18 months later with suspected lymphoma. Clinical examination revealed a progressive lymphadenopathy. Diagnoses. Histopathologic lymph node features, anemia, elevated CRP and IL6 levels, splenomegaly, and hypoalbuminemia indicated multicentric Castleman (MCD) disease. Interventions. The patient was treated intravenously with a dose of 11 mg/kg siltuximab every 3 weeks. Outcomes. Timely correct diagnosis through the stringent use of consensus diagnostic criteria and sufficient siltuximab therapy has considerably promoted favorable clinical outcomes in a patient suffering from MCD.

Bone Marrow Findings of Idiopathic Multicentric Castleman Disease: A Histopathologic Analysis and Systematic Literature Review

Idiopathic multicentric Castleman disease (iMCD) is a polyclonal lymphoproliferative disorder characterized by constitutional symptoms, generalized lymphadenopathy, cytopenias, and multi-organ dysfunction due to excessive cytokines, notably Interleukin-6. iMCD is often sub-classified into iMCD-TAFRO, which is associated with thrombocytopenia (T), anasarca (A), fever/elevated C-reactive protein (F), renal dysfunction (R), and organomegaly (O), and iMCD-NOS, which is typically associated with thrombocytosis and hypergammaglobulinemia. The diagnosis of iMCD is challenging as consensus clinico-pathological diagnostic criteria were only recently established and include several non-specific lymph node histopathological features. Identification of further clinico-pathological features commonly found in iMCD could contribute to more accurate and timely diagnoses. We set out to characterize bone marrow (BM) histopathological features in iMCD, assess differences between iMCD-TAFRO and iMCD-NOS, and determine if these findings are specific to iMCD. Examination of BM specimens from 24 iMCD patients revealed a high proportion with hypercellularity, megakaryocytic atypia, reticulin fibrosis, and plasmacytosis across patients with both iMCD-NOS and iMCD-TAFRO with significantly more megakaryocytic hyperplasia (p=0.001) in the iMCD-TAFRO cases. These findings were also consistent with bone marrow findings from 185 published cases of iMCD-NOS and iMCD-TAFRO. However, these findings are relatively nonspecific as they can be seen in various other infectious, malignant, and autoimmune diseases. This article is protected by copyright. All rights reserved.

Castleman disease

Castleman disease (CD), a heterogeneous group of disorders that share morphological features, is divided into unicentric CD and multicentric CD (MCD) according to the clinical presentation and disease course. Unicentric CD involves a solitary enlarged lymph node and mild symptoms and excision surgery is often curative. MCD includes a form associated with Kaposi sarcoma herpesvirus (KSHV) (also known as human herpesvirus 8) and a KSHV-negative idiopathic form (iMCD). iMCD can present in association with severe syndromes such as TAFRO (thrombocytopenia, ascites, fever, reticulin fibrosis and organomegaly) or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes). KSHV-MCD often occurs in the setting of HIV infection or another cause of immune deficiency. The interplay between KSHV and HIV elevates the risk for the development of KSHV-induced disorders, including KSHV-MCD, KSHV-lymphoproliferation, KSHV inflammatory cytokine syndrome, primary effusion lymphoma and Kaposi sarcoma. A CD diagnosis requires a multidimensional approach, including clinical presentation and imaging, pathological features, and molecular virology. B cell-directed monoclonal antibody therapy is the standard of care in KSHV-MCD, and anti-IL-6 therapy is the recommended first-line therapy and only treatment of iMCD approved by the US FDA and EMA.

Clinical and Pathological Characteristics of Hyaline-Vascular Type Unicentric Castleman Disease: A 20-Year Retrospective Analysis

The first case of hyaline vascular type of unicentric Castleman disease (HV-UCD) was reported more than six decades ago. Since patients with HV-UCD are often asymptomatic and this condition is generally discovered incidentally on imaging tests, most of the previous reports were of mediastinal origin detected by chest radiography. In recent years, improved access to imaging modalities has provided new insights in the diagnosis of this condition. In this study, we reviewed the detailed clinical and pathological findings of 38 HV-UCD cases (20 males and 18 females, mean age: 42.8 years). The most common site involved was the abdominal cavity (34.2%), followed by mediastinum (23.7%) and retroperitoneum (15.8%). In the abdominal cavity, mesenteric origin was the most common. The mean size of masses was 4.8 cm. Pathologically, thick hyalinized collagen fibers surrounding large blood vessels and calcification were observed (81.6% and 23.7%, respectively). Multinucleated giant cells resembling Warthin–Finkeldey cell were also observed in occasional cases (23.7%). This is a unique paper that summarizes detailed clinical and pathological findings of a large series of a rare disease. The clinical information presented in this paper is more plausible than previous views and is useful for accurate diagnosis and understanding of the disease.

Epidemiology and treatment patterns of idiopathic multicentric Castleman disease in the era of IL-6 directed therapy

We developed a novel algorithm based on a disease-specific ICD code and diagnostic criteria to calculate incidence and prevalence of iMCD.

Treatment with siltuximab is uncommon in those with iMCD, despite being the only US Food and Drug Administration– approved therapy.

The epidemiology of human herpesvirus-8–negative/idiopathic multicentric Castleman disease (iMCD) remains incompletely understood. Prior epidemiologic studies of CD and iMCD have been hampered by difficulties in accurate case ascertainment resulting from a lack of uniform diagnostic criteria and a disease-specific International Classification of Diseases (ICD) code. In this study, we provide reliable estimates of CD and iMCD in the United States using a novel claims-based algorithm that includes a CD-specific ICD (10th revision) diagnosis code (D47.Z2) supported by the presence of ≥2 claims codes corresponding to the minor criteria from the international evidence-based diagnostic criteria for iMCD. We additionally analyzed the treatment classes and patterns in the clinical course of patients with iMCD. Using an administrative claims database of 30.7 million individuals enrolled between 1 January 2017 and 31 December 2018, we identified 254 patients with iMCD, with an estimated annual incidence and prevalence of 3.4 (95% confidence interval [CI], 1.4-9.2) and 6.9 (95% CI, 3.7-13.3) cases per million, respectively. Among patients with iMCD, 39% received corticosteroid monotherapy, 33.1% received no iMCD-directed treatment, and 9.8% received interleukin-6 (IL-6)–targeted therapy with tocilizumab or siltuximab. Siltuximab, which is the only US Food and Drug Administration–approved treatment and established first-line treatment recommendation, was used in only 8.7% of patients with iMCD. This study provides the most up-to-date understanding of the iMCD disease burden in the United States and identifies a major unmet treatment need for IL-6–directed therapy in this vulnerable cohort.

Discovery and validation of a novel subgroup and therapeutic target in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a poorly understood hematologic disorder involving cytokine-induced polyclonal lymphoproliferation, systemic inflammation, and potentially fatal multiorgan failure. Although the etiology of iMCD is unknown, interleukin-6 (IL-6) is an established disease driver in approximately one-third of patients. Anti-IL-6 therapy, siltuximab, is the only US Food and Drug Administration-approved treatment. Few options exist for siltuximab nonresponders, and no validated tests are available to predict likelihood of response. We procured and analyzed the largest-to-date cohort of iMCD samples, which enabled classification of iMCD into disease categories, discovery of siltuximab response biomarkers, and identification of therapeutic targets for siltuximab nonresponders. Proteomic quantification of 1178 analytes was performed on serum of 88 iMCD patients, 60 patients with clinico-pathologically overlapping diseases (human herpesvirus-8-associated MCD, N = 20; Hodgkin lymphoma, N = 20; rheumatoid arthritis, N = 20), and 42 healthy controls. Unsupervised clustering revealed iMCD patients have heterogeneous serum proteomes that did not cluster with clinico-pathologically overlapping diseases. Clustering of iMCD patients identified a novel subgroup with superior response to siltuximab, which was validated using a 7-analyte panel (apolipoprotein E, amphiregulin, serum amyloid P-component, inactivated complement C3b, immunoglobulin E, IL-6, erythropoietin) in an independent cohort. Enrichment analyses and immunohistochemistry identified Janus kinase (JAK)/signal transducer and activator of transcription 3 signaling as a candidate therapeutic target that could potentially be targeted with JAK inhibitors in siltuximab nonresponders. Our discoveries demonstrate the potential for accelerating discoveries for rare diseases through multistakeholder collaboration.

Unusual Presentation of Castleman's Disease Encroaching on the Brachial Plexus

Castleman's disease is an uncommon benign lymphoproliferative disorder that commonly involves the mediastinum. We report an unusual case that involves the presentation of unicentric Castleman's disease in a 52-year-old female. The patient had a supraclavicular mass extending onto the brachial plexus. The approach to the treatment and plan for supraclavicular masses is complex due in part to the extensive list of differential diagnoses possible. In this case specifically, while the mass was ultimately determined to be benign, post-surgery, the location of the mass intraoperatively made for a very technically challenging and complex dissection. Post surgical resection, the patient reported no complications. This case highlights the importance of clinical judgement, imaging and surgical technique in removing a mass encroaching on the brachial plexus.

Adult-onset Still's disease in focus: Clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies

BACKGROUND

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology, characterized by a clinical triad of high spiking fever, arthralgia (± arthritis), and evanescent skin rash. Management of AOSD poses several challenges, including difficulty in diagnosis and limited therapeutic options. In this review, we examined whether AOSD and systemic juvenile idiopathic arthritis (SJIA) represent a continuum of the same disease. We also explored the latest available evidence related to prevalence, clinical and laboratory manifestations, complications, diagnostic challenges, novel biomarkers, and treatment options in the era of biologics and identified the unmet needs of patients with AOSD.

METHODS

A comprehensive systematic literature search was performed in the Embase and MEDLINE (via PubMed) literature databases. The search was limited to human studies published in English from inception up to March 2020. Additionally, abstracts presented at various conferences were screened and hand searches were performed. Publications were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 123 publications were identified through the literature search, majority of which were case series and retrospective observational studies. AOSD and SJIA are widely considered part of the same disease spectrum owing to similarities in their clinical and biological features. The clinical presentation of AOSD is highly variable, accompanied by a broad spectrum of disease manifestations. Recent evidence suggests that the AOSD disease course can be classified into two distinct categories: "systemic" and "articular." Furthermore, AOSD patients may experience various life-threatening complications, such as macrophage activation syndrome - reported in as high as 23% of AOSD patients and considered to be the most severe complication characterized by a high mortality rate. The ambiguity in presentation and lack of serologic markers make the diagnosis of AOSD difficult, often leading to a delay in diagnosis. Given these limitations, the Yamaguchi and Fautrel criteria are the most widely used diagnostic tools in clinical practice. It has been observed that a clinical diagnosis of AOSD is generally reached by exclusion while investigating a patient with fever of unknown origin. Recent advances have demonstrated a major role of proinflammatory cytokines, such as interleukin (IL)-1, IL-6, IL-18, and IL-37, and other biomarkers in the pathogenesis and management of AOSD. Owing to the rarity of the disease, there are very limited clinical trials evaluating management strategies for AOSD. The current AOSD treatment paradigm includes non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids initially, conventional synthetic disease-modifying anti-rheumatic drugs in steroid-refractory patients, and biologics in those resistant to conventional treatment. Only a few country-specific guidelines for the management of AOSD have been published, and a treat-to-target approach, as previously recommended for SJIA, is still lacking. Canakinumab is the only FDA-approved biologic for the treatment of AOSD.

CONCLUSION

Emerging evidence supports that AOSD and SJIA represent a continuum of the same disease entity. Despite advancements in the understanding of AOSD, it continues to pose a substantial burden on patients and the healthcare systems, and substantial unmet needs exist across key domains such as the pathway to diagnosis, use of biomarkers in clinical practice, and standardized treatment strategies. Further research and collaboration is crucial for optimizing the diagnosis and management of AOSD patients.

A case of metastatic renal cell carcinoma with concomitant Castleman's disease treated with immunotherapy

Castleman's disease (CD) is an uncommon lymphoproliferative process that can present concurrent to other solid organ malignancy, especially in selected populations. Concomitant CD and renal cell carcinoma (RCC) are challenging in terms of diagnosis and treatment. Assessment of CD involvement is a crucial step in selecting the optimal treatment strategy. Here we report a case of metastatic RCC and concurrent CD treated with surgery and immunotherapy.

International evidence-based consensus diagnostic and treatment guidelines for unicentric Castleman disease

Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms (multicentric CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)-associated MCD, POEMS-associated MCD, and HHV-8-/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti-interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

An Immunocompetent HIV-Negative Elderly Patient with Low-Grade Fever, Generalized Lymphadenopathy, Splenomegaly, and Acute Phase Response: Do Not Forget Castleman Disease

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder that mainly affects middle-aged patients with human immunodeficiency virus (HIV) infection. However, HIV-negative patients can also be affected representing a small proportion of the total MCD cases. Of note, recent studies from China in HIV-negative patients with MCD have suggested that the onset of the disease can be observed in younger age than previously thought. If undiagnosed and untreated, the MCD has a poor prognosis and may progress to lymphoma. We present an 82-year-old immunocompetent male patient who was admitted to our department because of low-grade fever, cachexia, anasarca, hepatosplenomegaly, and generalized lymphadenopathy. Laboratory findings showed anemia and increased markers of inflammation including hyperferritinemia and polyclonal hyperglobulinemia. Infectious causes including HIV were ruled out. Histological examination of a cervical lymph-node revealed lesions supportive of MCD diagnosis. Of note, the outer-zone plasmablasts' nuclei stained positive for human herpesvirus-8 (HHV8). The patient received 4 cycles of cyclophosphamide, vincristine, and dexamethasone with regression of all symptoms. This case underlines that HHV8-associated MCD should be considered as a rare cause of generalized lymphadenopathy even in HIV-negative immunocompetent patients when other causes have been appropriately excluded because a timely diagnosis can be life-saving.

Cutaneous involvement as initial presentation of multicentric plasmacytic Castleman disease

Castleman disease (CD) is an unusual lymphoproliferative disorder characterized by multiple lymphadenopathy accompanied by marked systemic inflammatory symptoms. CD can be unicentric (UCD) or multicentric (MCD), and it can be classified into three types based on histopathology: hyaline vascular type, plasma cell type, and mixed hyaline vascular and plasma cell type. CD involving skin is an unusual clinical manifestation. Abnormalities including rash, hyperpigmentation, cherry hemangiomatosis, paraneoplastic pemphigus, and Kaposi sarcoma have been reported to occur in MCD. Here, we reported an unusual case of MCD which presented initially with disseminated dark brown papules, patches, and plaques, and pathologically demonstrated plasma cell type CD, a finding which is rarely reported. The peculiar clinicopathological features will be discussed.

The clinical, laboratory, and radiologic improvement due to siltuximab treatment in idiopathic multicentric Castleman's disease

BACKGROUND/AIMS

Idiopathic multicentric Castleman disease (iMCD) comprises approximately 30% of all cases of Castleman disease. It is characterized by constitutional symptoms, enlarged lymph nodes at multiple anatomical sites, and laboratory test abnormalities, which are primarily related to the overproduction of interleukin 6 (IL-6). Siltuximab is a human-mouse chimeric immunoglobulin G1κ monoclonal antibody against human IL-6. In view of the limited treatment options for iMCD, this study aimed to evaluate the efficacy and safety of siltuximab in the management of this condition.

METHODS

In this real-world retrospective study, we administered siltuximab to 15 patients with iMCD who previously received conventional chemotherapy and/or steroid pulse therapy. The median time to a durable symptomatic response was 22 days (range, 17 to 56). The serum hemoglobin and albumin levels and erythrocyte sedimentation rates significantly normalized after the first 3 months of siltuximab treatment. Lymph node involution, assessed using imaging, was relatively gradual, demonstrating a complete or partial response at 6 months.

RESULTS

On an average, the improvements in clinical, laboratory, and radiologic parameters of iMCD in responders were observed after one, three, and eight cycles of siltuximab treatment, respectively. Siltuximab demonstrated a favorable safety profile, and prolonged treatment was well-tolerated.

CONCLUSION

Despite the small sample size of the present study, the results are encouraging and demonstrate the potential of siltuximab as the first-line treatment of iMCD. Further large multicenter studies are needed to evaluate the clinical outcomes and adverse events associated with siltuximab.

ACCELERATE: A Patient-Powered Natural History Study Design Enabling Clinical and Therapeutic Discoveries in a Rare Disorder

Geographically dispersed patients, inconsistent treatment tracking, and limited infrastructure slow research for many orphan diseases. We assess the feasibility of a patient-powered study design to overcome these challenges for Castleman disease, a rare hematologic disorder. Here, we report initial results from the ACCELERATE natural history registry. ACCELERATE includes a traditional physician-reported arm and a patient-powered arm, which enables patients to directly contribute medical data and biospecimens. This study design enables successful enrollment, with the 5-year minimum enrollment goal being met in 2 years. A median of 683 clinical, laboratory, and imaging data elements are captured per patient in the patient-powered arm compared with 37 in the physician-reported arm. These data reveal subgrouping characteristics, identify off-label treatments, support treatment guidelines, and are used in 17 clinical and translational studies. This feasibility study demonstrates that the direct-to-patient design is effective for collecting natural history data and biospecimens, tracking therapies, and providing critical research infrastructure.

Idiopathic multicentric Castleman disease with Sjögren's syndrome and secondary membranous nephropathy: a case report and review of the literature

Background

Idiopathic multicentric Castleman disease (iMCD) is an uncommon lymphoproliferative disorder and lacks treatment consensus. Herein, we report a case of iMCD complicated with Sjögren’s syndrome (SS) and secondary membranous nephropathy (SMN).

Case presentation

A 45-year-old female with dry mouth for 3 months and anasarca and proteinuria for 2 months was admitted. She also experienced chest tightness, wheezing, fever, weight loss, moderate proteinuria and hypoalbuminemia. A computed tomography (CT) scan revealed a tissue mass in the thymus area and enlarged multiple lymph nodes. Her symptoms did not improve after resection of the thymus mass. The pathological findings were “reactive hyperplasia of the mediastinal lymph nodes and thymic hyperplasia”. Lymph node biopsy findings confirmed iMCD with human herpes virus-8 (HHV-8) negativity. Based on anti-nuclear antibody (ANA) 1:320, anti-SSA and anti-SSB antibody positivity, salivary flow less than 0.1 ml/min and lip biopsy with focal lymphocytic sialadenitis, SS was diagnosed. Kidney biopsy showed secondary membranous nephropathy with endocapillary cell proliferation and infiltration of plasma cells and lymphocytes in the tubulointerstitium. Serum interleukin-6 (IL-6) levels were significantly increased, and therapy with tocilizumab (anti-IL-6 receptor antibody) worked well. The combination of cyclophosphamide (CyS) with methylprednisolone (MP) maintained satisfactory remission.

Conclusions

Our case of iMCD with SS and SMN is rare. There is a need for increased awareness of the disease to avoid unnecessary procedures and misdiagnoses. IL-6 was extremely high, and there was a rapid response to anti-IL-6 receptor agents. The combination of CyS with MP maintained complete remission.

FDG PET/CT Findings of Castleman Disease Assessed by Histologic Subtypes and Compared with Laboratory Findings

Castleman disease (CD) is a relatively rare lymphoproliferative disorder and the pathophysiology of the subtypes are incompletely understood. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) demonstrates the metabolic activity of inflammatory and tumorous conditions. The FDG uptake intensity and sites of involved lesions on FDG PET/CT were assessed by histologic subtypes, and compared to the patient's hemoglobin, platelet, albumin, and high-sensitivity C-reactive protein (hs-CRP) levels. In total, 60 PET/CT images of 44 consecutive CD patients were included: 4 (9%) unicentric and 40 (91%) multicentric; 21 (48%) hyaline vascular subtype, 16 (36%) plasma cell, and 7 (16%) mixed or unclassified. The maximum standardized uptake value (SUVmax) and tumor-to-liver (T/L) ratio of involved lymph nodes (LNs) were 5.3 ± 2.4 (range, 1.6-11.5) and 2.8 ± 1.6 (range, 1.1-9.6), respectively, with no significant difference between the histologic subtypes. Higher number of involved LN stations and presence of extra-nodal involvement on FDG PET/CT were associated with thrombocytopenia, hypoalbuminemia, and elevated hs-CRP levels (p values < 0.05). FDG-avidity was not different by histologic subtypes and did not correlate with laboratory findings. However, the extent of nodal and extra-nodal involvement as noted on FDG PET/CT was significantly associated with abnormal laboratory findings in patients with CD.