The full spectrum of Castleman disease: 273 patients studied over 20 years

Castleman disease coexisting with papillary thyroid carcinoma: A case report

Castleman disease (CD) is a rare lymphoproliferative disorder of unknown etiology characterized by lymph node enlargement. CD cannot be confirmed by preoperative puncture cytology, and definitive diagnosis depends on postoperative histopathology. Due to the lack of characteristic clinical manifestations and imaging features, in clinical practice, CD is often easily missed or misdiagnosed, and it is frequently mistaken for lymphoma or autoimmune diseases. Cases of CD that coexist with papillary thyroid carcinoma (PTC) are particularly rare and are often misdiagnosed as PTC with lymph node metastasis. The present study discusses the diagnosis, treatment process and prognosis of a case involving PTC that is complicated with unilateral, single-center CD. This patient was diagnosed with a right lobe nodal gland of the thyroid gland combined with a mass in the left supraclavicular fossa. The postoperative pathological examination revealed a right lobe papillary carcinoma of the thyroid gland with metastasis of the right cervical lymph node combined with CD in the left supraclavicular fossa. The immunohistochemical results of the right cervical lymph node were thyroglobulin (+), thyroid transcription factor-1(+). Immunohistochemical results of left supraclavicular fossa mass: Bcl-2 (low expression in the germinal center, high expression outside), Bcl-6 (germinal center +), Cyclin D1 (-), cluster of differentiation 38 (focally+). In future clinical practice, when encountering PTC with mediastinal masses, clinicians should consider not only common lymph node metastases but also the possibility of CD. Overall, this study aims to provide valuable insights and experience for clinicians regarding CD and PTC.

Characterizing the heterogeneity of Castleman disease and oligocentric subtype: findings from the ACCELERATE registry

ABSTRACT

Castleman disease (CD) describes a group of rare lymphoproliferative disorders that exhibit a wide range of symptomatology and degree of lymphadenopathy, particularly across the 2 forms of CD with unknown etiology, unicentric CD (UCD), and human herpesvirus-8-negative/idiopathic multicentric CD (iMCD). Whereas UCD cases typically present with localized lymphadenopathy and mild symptoms, iMCD involves multicentric lymphadenopathy and cytokine storm-driven symptoms with 3 recognized clinical phenotypes. Increasingly, there are anecdotal reports of cases that do not fit into this framework, but these cases have not been systematically described. Herein, we use the ACCELERATE natural history registry to characterize the spectrum of CD based on disease features, symptomatology, and severity. Our results characterize a cohort of 179 CD cases, which were reviewed and confirmed by an expert panel of clinicians and hematopathologists. We show that patients with CD present on a continuous spectrum of clinical phenotypes, and we describe oligocentric CD (OligoCD), an intermediate phenotype that does not fit the criteria for UCD or iMCD. These cases tend to have "oligocentric" lymphadenopathy (median [interquartile range] regions of lymphadenopathy, 3.0 [2.0-4.0]) in a regional pattern and exhibit a mild clinical phenotype that is more similar to UCD than iMCD. We also show that patients with OligoCD are inconsistently categorized as UCD vs iMCD, highlighting the need for this characterization. Future data collected through ACCELERATE may further elucidate the natural history and risk profile of these patients.

Spatial transcriptomics study of Castleman disease

BACKGROUND

Castleman Disease (CD) is a rare lymphoproliferative disorder of uncertain etiology, primarily characterized by painless lymphadenopathy. To further understand the possible pathogenesis of the disease, we utilized spatial transcriptomics to explore CD.

METHODS

Spatial transcriptomics was performed on FFPE samples from lymph nodes of three CD patients with different histologic types and one normal lymph node.

RESULTS

The sample was categorized by analysis into 14 clusters, including B cells, plasma cells, BECs, LECs, CD4 + T cells, CD8 + T cells, macrophages, monocytes, cycling cells, myofibroblasts, mDCs, NKCs, Tfh and NESCs. Our study showed that the lesion cells of CD might be B cells. In addition to this, we found that mesenchymal cells, especially myofibroblasts, play an important role in disease progression and there was a large heterogeneity of cellular communication between cell clusters in different histologic types of CD.

CONCLUSIONS

Through this study we have gained a better understanding of the pathogenesis of CD. It provides new ideas for the subsequent exploration of CD and directions for the development of new clinical drugs.

Pelvic unicentric Castleman's disease mimicking accessory spleen: A rare presentation of Castleman's disease, a case report and literature report

INTRODUCTION AND IMPORTANCE

Castleman disease, a rare, mostly benign lymphoproliferative disorder, is classified as unicentric or multicentric Castleman disease, with HHV-8 association affecting the latter. Unicentric Castleman disease typically presents as a single enlarged lymph node, most often mediastinal, while multicenter Castleman disease involves multiple lymph nodes. Treatment depends on the type and severity, ranging from surgical resection for unicentric Castleman disease to chemotherapy for multicentric Castleman disease.

CASE PRESENTATION

A 28-year-old Ethiopian man presented with three months of pelvic pain, altered bowel habits, and urinary frequency. The physical examination was unremarkable. Investigations revealed a retroperitoneal pelvic mass, initially suspected to be an accessory spleen. Surgery revealed a 10 × 8 × 4 cm mass. Histopathology showed features consistent with unicentric Castleman disease, confirmed by characteristic "onion skin" and "lollipop" appearances, CD20 positivity, and negative HHV-8 and Bcl-2. The patient recovered well after surgical resection.

CASE DISCUSSION

Pelvic unicentric Castleman disease is a rare presentation of this uncommon disorder, typically affecting the mediastinum. While its pathogenesis is unclear, it's not associated with HHV-8, IL-6 overproduction, or human immunodeficiency virus in all cases (as in this patient). Unicentric Castleman disease is characterized by localized symptoms or may be asymptomatic, unlike multicentric Castleman disease which presents with systemic manifestations. Imaging (ultrasound and CT in this case) guides diagnosis, with histopathology confirming the characteristic "onion skin" and "lollipop" appearances. Surgical excision is the treatment of choice for unicentric Castleman disease, offering excellent outcomes (as seen in the patient). Multicentric Castleman disease requires more extensive treatment, with a less favorable prognosis. Long-term follow-up is crucial due to the risk of malignant transformation.

CONCLUSION

Unicentric pelvic Castleman disease, a rare condition sometimes confused with accessory spleen, requires histopathological diagnosis. While often linked to HIV/AIDS or HHV-8, it can occur without risk factors and usually responds well to surgical excision.

A diagnostic and therapeutically challenging presentation of unicentric mesenteric Castleman disease: A case report

Castleman disease (CD) is a rare lymphoproliferative disorder primarily manifesting as either Multicentric CD (MCD) or Unicentric CD (UCD), with Unicentric Mesenteric CD (UMCD) representing a less common subtype within the UCD category. The present study presented an encounter with a 29-year-old male patient afflicted by UMCD, presenting with significant morbidity attributed to a sizable mesenteric mass. The diagnostic and therapeutic management of this condition posed notable challenges. In the absence of any additional abnormalities detected in auxiliary examinations, a distinct soft tissue density lesion in the abdominal region was revealed by computed tomography (CT). Despite the patient's reluctance to pursue further diagnostic procedures such as fine needle aspiration, a surgical approach was adopted under the suspicion of malignancy to establish a definitive diagnosis and implement treatment, confirming the condition as UMCD. Subsequent adjuvant chemotherapy was performed postoperatively. Fortunately, the patient achieved complete recovery, with no tumor recurrence observed during the 5-year follow-up period post-surgery. Due to the special location of UMCD, its preoperative diagnosis posed challenges and the most effective treatment remains a topic of debate. The prevalent instances of delayed diagnosis and misdiagnosis underscore a deficiency in comprehending the etiology and features of the disease, essential for advancing novel therapeutic strategies. CT imaging and pathological examination both play a crucial role in UMCD diagnosis. The present study supported surgery as the primary treatment modality for UMCD, with chemotherapy and immunotherapy offering additional benefits for appropriately selected patients.

Unicentric Castleman disease-associated paraneoplastic pemphigus successfully managed with surgical resection and rituximab

We report a case of a woman in her early 20s who presented with chronic and refractory oro-oesophageal ulcers and significant weight loss. The common causes of refractory ulcers were ruled out. Biopsy from the oesophageal ulcers was suggestive of paraneoplastic pemphigus (PNP). The patient underwent a PET scan that revealed an incidental mass. PET-guided biopsy from the infrarenal mass was suggestive of unicentric Castleman disease (UCD). She was managed with local surgical resection, steroids and rituximab. The current case highlights that PNP can be the presenting manifestation of an underlying UCD. In addition, it also highlights the adjunctive role of rituximab in the management of UCD-associated PNP in patients with suboptimal response to steroids and surgical resection.

18F-FDG PET/CT metabolic parameters are correlated with clinical features and valuable in clinical stratification management in patients of castleman disease

BACKGROUND

Castleman disease (CD) is a rare lymphoproliferative disorder. This study is to evaluate the correlation between 18F-flurodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) and clinical features in CD patients, and exploring its value in distinguishing disease severity and assisting in risk stratification.

METHODS

We retrospectively enrolled 93 patients with newly diagnosed CD. Traditional semi-quantitative 18F-FDG PET/CT parameters including the maximum standardized uptake value (SUVmax), total metabolic lesion volume (MLV), total lesion glycolysis (TLG) were measured, and the lymph node to liver ratio of SUVmax (LLR), lymph node to mediastinal blood pool of SUVmax (LMR), spleen to liver ratio of SUVmax (SLR) and No. of involved lymph node stations (LNS) were calculated. The correlation between these metabolic parameters and clinical features were studied using a univariate analysis. The influencing factors of CD severity were determined by univariate and multivariate analysis. The optimal cut-off values for metabolic parameters were obtained by receiver operating characteristic (ROC) curve.

RESULTS

A total of 20 unicentric CD (UCD) and 73 multicentric CD (MCD) cases were included, with the highest SUVmax of Lymph nodes ranged 1.40 ~ 28.18 (median, 4.86). The metabolic parameters (SUVmax, MLV, TLG, LLR, LMR, SLR) in MCD were significantly higher than those in UCD (p < 0.05). There were significant differences in MLV, TLG, LLR and SLR among different histological subtypes (p < 0.05). The No. of involved lymph node stations (LNS) and spleen-to-liver ratio (SLR) were significantly correlated with laboratory findings. In univariate and multivariate analyses, SLR (p = 0.011; OR value = 14.806) and HGB (p = 0.004; OR value = 0.044) exhibited an independent correlation with disease severity. The ROC curve revealed that SLR had a sensitivity of 77.4%, specificity of 69.4% and AUC of 0.761 (cut-off value = 1.04; p < 0.001) in discriminating severity of CD. SLR also showed significant statistical differences between severe and non-severe idiopathic MCD (iMCD) (p = 0.016).

CONCLUSIONS

SLR is closely related to clinical features of CD, and can relatively effectively differentiate the severity of CD and assist in the clinical risk stratification of iMCD.

Unicentric Castleman Disease: Updates and Novel Insights Into Spindle Cell Proliferations and Aggressive Forms of a Localized Disease

Castleman Disease (CD) is a rare lymphoproliferative disorder that can be separated into two primary forms: Unicentric Castleman disease (UCD) and multicentric Castleman disease (MCD). UCD is localized, while MCD is systemic. Though UCD generally has a favorable prognosis following surgical resection, more aggressive forms of this disease have been identified, including cases associated with dendritic and spindle cell proliferation. Genetic analysis has deepened our understanding of UCD. Despite advancements in better understanding the pathophysiology of UCD, challenges persist in the diagnosis, management, and treatment due to its rarity and heterogeneity. Here, we review current knowledge on UCD, highlighting the epidemiology, clinical presentation, diagnostic criteria, and treatment options while emphasizing the need for further research and innovation in therapeutic strategies.

Unraveling the Kaposi Sarcoma-Associated Herpesvirus (KSHV) Lifecycle: An Overview of Latency, Lytic Replication, and KSHV-Associated Diseases

Kaposi sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus and the etiological agent of several diseases. These include the malignancies Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD), as well as the inflammatory disorder KSHV inflammatory cytokine syndrome (KICS). The KSHV lifecycle is characterized by two phases: a default latent phase and a lytic replication cycle. During latency, the virus persists as an episome within host cells, expressing a limited subset of viral genes to evade immune surveillance while promoting cellular transformation. The lytic phase, triggered by various stimuli, results in the expression of the full viral genome, production of infectious virions, and modulation of the tumor microenvironment. Both phases of the KSHV lifecycle play crucial roles in driving viral pathogenesis, influencing oncogenesis and immune evasion. This review dives into the intricate world of the KSHV lifecycle, focusing on the molecular mechanisms that drive its latent and lytic phases, their roles in disease progression, and current therapeutic strategies.

No evidence for active viral infection in unicentric and idiopathic multicentric Castleman disease by Viral-Track analysis

Castleman disease (CD) is a rare hematologic disorder characterized by pathologic lymph node changes and a range of symptoms due to excessive cytokine production. While uncontrolled infection with human herpesvirus-8 (HHV-8) is responsible for the cytokine storm in a portion of multicentric CD (HHV-8-associated MCD) cases, the etiology of unicentric CD (UCD) and HHV-8-negative/idiopathic MCD (iMCD) is unknown. Several hypotheses have been proposed regarding the pathogenesis of UCD and iMCD, including occult infection given the precedent established by HHV-8 infection. To investigate potential active infections in UCD and iMCD, we implemented Viral-Track, a computational method that identifies viral mRNA sequences from next-generation sequencing data. We applied Viral-Track to short sequencing reads from a cohort of UCD (n = 22), iMCD (n = 19), and controls (n = 86). While viral sequences for several unusual viruses were identified in individual CD patients,  sequences for the same virus were not found across multiple CD patients or they were not specific to CD samples and were also found in non-CD samples. These results suggest that active viral infection is unlikely to be a pathological driver of UCD or iMCD.

Identifying Castleman disease from non-clonal inflammatory causes of generalized lymphadenopathy

Idiopathic multicentric Castleman disease (iMCD) is a rare, life-threatening subtype of Castleman disease (CD), which describes a group of rare, polyclonal lymphoproliferative disorders that demonstrate characteristic histopathology and variable symptomatology. iMCD involves a cytokine storm that occurs due to an unknown cause. Rapid diagnosis is required to initiate appropriate, potentially life-saving therapy, but diagnosis is challenging and impeded by clinical overlap with a wide spectrum of inflammatory, neoplastic, and infectious causes of generalized lymphadenopathy. Diagnosis, which requires both consistent histopathologic and clinical criteria, can be further delayed in the absence of close collaboration between clinicians and pathologists. A multimodal assessment is necessary to effectively discriminate iMCD from overlapping diseases. In this review, we discuss a pragmatic approach to generalized lymphadenopathy and clinical, laboratory, and histopathological features that can aid with identifying iMCD. We discuss diagnostic barriers that impede appropriate recognition of disease features, diagnostic criteria, and evidence-based treatment recommendations that should be initiated immediately following diagnosis.

Interleukin-6 transcripts up-regulation in lymph nodes from unicentric and multicentric Castleman disease

Introduction

Castleman disease (CD) represents a spectrum of heterogeneous lymphoproliferative disorders sharing peculiar histopathological features, clinically subdivided into unicentric CD (UCD) and multicentric CD (MCD) and presenting with variable inflammatory symptoms. Interleukin (IL)-6 and other cytokines play a major role in mediating CD inflammatory manifestations. Although the local microenvironment seems to be among the major sources of hypercytokinemia, the precise cellular origin of IL-6 production in CD is still debated.

Methods

A series of five nodal CD of different subtypes (one UCD, two idiopathic MCDs [iMCDs], one HIV-negative human herpesvirus 8 (HHV8)-associated MCD, and one HIV-positive HHV8-associated MCD) and a non-CD reactive control were tested using RNAscope analysis and a dual in situ hybridization (ISH)/immunohistochemistry technique, in order to quantify IL-6 expression and its spatial distribution. Quantitative analyses of in situ mRNA were performed on digitalized slides using the HISTOQUANT software (3DHISTECH) and differences between cases were evaluated by the Kruskal-Wallis test.

Results

RNA-ISH documented increased IL-6 expression in all CD lymph nodes, independently from clinical and pathological subtypes, however, the highest levels were found in HHV8+ cases and statistically significant differences in IL-6 expression were found only between HHV8+ MCD and control case. Dual RNA-ISH for IL6 coupled with immunohistochemistry analysis showed that IL-6 was overexpressed in CD31-positive endothelial cells in 5/5 CD tested cases but not in the control case.

Conclusion

Our findings suggest that nodal IL-6 expression seems to be significantly upregulated in HHV8+ MCD, but a trend toward increased nodal IL-6 expression was noticed also in UCD and iMCD-not otherwise specified. CD31+ endothelial cells probably represent one of the major sources of IL-6 production in the nodal microenvironment.

Molecular Mechanisms of Kaposi Sarcoma-Associated Herpesvirus (HHV8)-Related Lymphomagenesis

Approximately 15-20% of cancers are caused by viruses. Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), is an oncogenic virus that is the etiologic agent of not only Kaposi sarcoma but also the lymphoproliferative disorders, primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD). KSHV can infect a broad tropism of cells, including B lymphocytes, wherein KSHV encodes specific viral proteins that can transform the cell. KSHV infection precedes the progression of PEL and MCD. KSHV establishes lifelong infection and has two phases of its lifecycle: latent and lytic. During the latent phase, viral genomes are maintained episomally with limited gene expression. Upon sporadic reactivation, the virus enters its replicative lytic phase to produce infectious virions. KSHV relies on its viral products to modulate host factors to evade immune detection or to co-opt their function for KSHV persistence. These manipulations dysregulate normal cell pathways to ensure cell survival and inhibit antiviral immune responses, which in turn, contribute to KSHV-associated malignancies. Here, we highlight the known molecular mechanisms of KSHV that promote lymphomagenesis and how these findings identify potential therapeutic targets for KSHV-associated lymphomas.

Clinicopathological characteristics of unicentric Castleman disease: A single-center experience of 12 patients

BACKGROUND

Castleman disease (CD) is an uncommon lymphoproliferative disorder with distinct pathological characteristics. Unicentric Castleman disease (UCD) presents as a single lymph node enlargement, often without significant symptoms. Complete surgical resection is the standard treatment for UCD. This study aimed to explore the clinicopathological features of UCD in a Taiwanese population.

METHODS

We retrospectively identified 12 patients with UCD who had undergone surgical treatment between January 1, 2006 and June 30, 2022 at the National Taiwan University Hospital. Clinical and radiological findings were retrieved from medical records. All available pathological slides were reviewed.

RESULTS

The patients' mean age was 38.1 years (range, 17 to 69); five (41.7%) were male, and seven (58.3%) were female. Nearly all cases of UCD were in the mediastinum, except for one case in the neck. Most patients were asymptomatic and without abnormal laboratory test results. Computed tomography revealed well-defined tumor borders, contrast enhancement, and occasional calcification. Ten patients underwent en bloc tumor resection, while the remaining two underwent partial resection. Among them, seven (58.3%) underwent video-assisted thoracoscopic surgery (VATS), and four (33.3%) underwent thoracotomy. The mean follow-up duration was 92 months. The patients who underwent total resection had no recurrence.

CONCLUSION

Detailed clinicopathological information on UCD in the Taiwanese population is present in our article. Both complete and partial surgery are effective for treatment. VATS may be preferred over thoracotomy due to less operative time and bleeding.

Overview of Research Status in Castleman Disease

Castleman disease (CD) is characterized by the proliferation of lymphoid tissue and encompasses a range of disorders that vary in clinical presentation, histopathological features, and therapeutic approaches. This article presents a comprehensive review of the current state of CD research, emphasizing the etiology, pathogenesis, clinical manifestations, diagnostic criteria, treatment options, and prognostic factors. CD is a relatively rare condition infrequently encountered in clinical practice. Certain subtypes of CD progress rapidly and pose a significant threat to patient health. Consequently, a timely and accurate diagnosis is crucial. This article aimed to equip clinicians and researchers with an updated and detailed understanding of CD, thereby enhancing the management of this complex condition.

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.

Clinical features and outcomes of retroperitoneal unicentric Castleman disease resected as sarcomas: insights from a high-volume sarcoma center

Background

Castleman disease (CD) is a rare lymphoproliferative disorder that can occur anywhere along the lymphatic pathway. Retroperitoneal unicentric Castleman disease (UCD) is an extremely rare manifestation. This study aims to explore the clinical features and surgical treatment of retroperitoneal UCD.

Methods

We retrospectively reviewed patients who underwent retroperitoneal tumor surgery and were diagnosed with CD based on postoperative pathology before December 31, 2022. Data from these patients were collected and analyzed.

Results

A total of 15 patients were included in the final analysis. All patients underwent radical resection under general anesthesia. Two out of 15 patients (13.3%) experienced serious complications but recovered well. There were no perioperative deaths. The median follow-up time was 78.5 months (range: 18-107.5 months), and no deaths or recurrences occurred during this period.

Conclusions

Surgical treatment for retroperitoneal UCD is safe. Patients with retroperitoneal UCD can achieve long-time survival through complete resection.

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.

A rare presentation of unicentric Castleman's disease in the thigh: A case report and review of literature

BACKGROUND

Castleman's disease (CD) is a rare lymphoproliferative, emulating both benign and malignant diseases. The diagnosis of CD is formulated upon the combination of clinical and laboratory criteria and ultimately confirmed by histopathological assessment. Due to its rarity, CD presents a challenge in treatment selection, with available options encompassing surgery, chemotherapy, and autologous stem cell transplantation. However, studies suggest that surgical resection of the lesion is the most effective treatment modality, especially for unicentric CD (UCD).

CASE SUMMARY

Here, we describe the case of a 25-year-old woman who presented with painless left thigh swelling for 10 wk. She had been following a low-fat diet to lose weight and had normal laboratory results. Magnetic resonance imaging revealed a well-circumscribed, demarcated cystic lesion located in the left inguinal region with eccentrically positioned signal void vascular structures, measuring 4.3 cm × 3 cm × 3.2 cm, likely of lymphoid origin. The patient underwent surgical resection, and the final histopathology showed a vascular proliferation and hyalinization of the vessel walls, along with atretic germinal centers traversed by penetrating vessels, consistent with CD. The patient was discharged home one day after the procedure in good condition, with a follow-up appointment scheduled in our outpatient clinic.

CONCLUSION

Although surgical resection is the mainstay for UCD, a multidisciplinary approach is needed due the lack of specific diagnostic features and treatments.

Ten-year anemia as initial manifestation of Castleman disease in the abdominal cavity: A case report

Castleman disease (CD) is a relatively rare lymphoproliferative disorder. Lesions predominantly originate on the chest and neck and rarely occur on the abdomen. A 34-year-old female presented to our hospital with an unexplained 10-year history of anemia. A pathological diagnosis of plasma cell-type CD was established. One cycle of chemotherapy (thalidomide, cyclophosphamide, and prednisolone) improved her anemia significantly. Prompt etiological diagnosis and early intervention are essential to address systemic manifestations in patients with CD, and it is crucial to consider CD as a differential diagnosis when intra-abdominal masses are detected.

Lymphadenopathy in the rheumatology practice: a pragmatic approach

Lymphadenopathy is a common clinical finding and diagnostic challenge within general medicine and rheumatology practice. It may represent a primary manifestation of an underlying immune-mediated disease or indicate an infectious or neoplastic complication requiring differing management. Evaluating lymphadenopathy is of particular relevance in rheumatology, given that lymph node enlargement is a common finding within the clinical spectrum of several well-known rheumatologic disorders including RA, SLE and SS. In addition, lymphadenopathy represents a hallmark manifestation of rare immunological diseases such as Castleman disease and IgG4-related disease that must be considered in the differential diagnosis because effective targeted treatments can now impact the prognosis of these conditions. In this review we present an overview of the clinical significance of lymphadenopathy in common and rare rheumatologic diseases and propose a practical approach to lymphadenopathy in the rheumatology practice. Differential diagnosis of Castleman disease and therapeutic options for this condition of increasing rheumatologic interest will be discussed in detail.

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.

Unicentric Castleman disease: A case report of an atypical presentation and successful management

INTRODUCTION

Castleman Disease (CD) is a rare benign disorder characterized by abnormal lymphoid tissue growth. It can be classified as unicentric CD (UCD) affecting a single lymph node region or multicentric CD (MCD) involving multiple regions. While UCD typically occurs in the mediastinum, MCD is associated with inflammatory symptoms and abnormal lab findings. We present a case of a young Syrian male with pelvic UCD, exhibiting unusual symptoms. Surgical excision led to complete recovery.

CASE PRESENTATION

A 27-year-old male presented with a well-defined pelvic mass discovered during routine ultrasonography. Symptoms included fever, fatigue, weight loss, and lower extremity numbness. Laboratory analysis revealed lymphocytopenia. Imaging identified a retroperitoneal pelvic mass, raising concerns of lymphoma. Surgical resection confirmed Castleman disease, specifically the hyaline vascular variant, dispelling malignancy concerns. Post-surgery, the patient demonstrated complete recovery, with normalized lymphocyte count and resolution of symptoms, affirming the effectiveness of the treatment.

DISCUSSION

Castleman Disease (CD) is characterized by abnormal lymphoid tissue growth. It presents as Unicentric (UCD) or Multicentric (MCD) forms. UCD cases are usually asymptomatic or show compressive symptoms due to mass effect, while MCD is associated with systemic symptoms. The estimated UCD incidence is 16 cases per million person-years, with median age at diagnosis around 30-34 years. Histologically, UCD is categorized into hyaline vascular (HV) and plasma cell (PC) variants. In this case, systemic symptoms and lymphocytopenia deviated from typical UCD presentation, leading to initial lymphoma suspicions. Surgical intervention facilitated recovery without adjuvant therapies.

CONCLUSION

This study emphasizes the spectrum of Castleman Disease (CD) manifestations, distinguishing Unicentric (UCD) and Multicentric (MCD) forms crucial for accurate management. It highlights atypical pelvic UCD presentation and successful surgical treatment's importance.

Stroma-Rich Hyaline Vascular Type of Castleman Disease: A Case Report and Literature Review

Castleman disease (CD) is a rare lymphoproliferative disorder characterized by abnormal lymph node enlargement. We present the first documented case of a stroma-rich variant of hyaline vascular Castleman disease in Saudi Arabia. A 24-year-old Saudi female known to have acetylcholine receptor antibody-positive myasthenia gravis (MG) presented with shortness of breath, oral thrush, and an acute myasthenia gravis exacerbation, necessitating intensive care unit (ICU) admission. During her hospitalization, she was found to have a large pelvic mass. The mass was surgically excised. The diagnosis of stroma-rich hyaline vascular Castleman disease was rendered after histopathological examination. The patient's symptoms improved after the surgery. This case underscores the importance of considering Castleman disease in complex clinical presentations, especially in the context of autoimmune and paraneoplastic diseases. Recognition and timely intervention are crucial for patient management. Additionally, the report adds to the global literature on Castleman disease, emphasizing the need for further research into its clinical manifestations and associations.

[Castleman's disease in the rheumatological practice]

The term Castleman's disease encompasses a group of rare lymphoproliferative diseases that show histopathological similarities in lymph node biopsy. Diagnostic criteria and a specific ICD-10 code have been available for a few years. Case studies listed at the beginning illustrate that close cooperation between clinicians and pathologists is required to enable a reliable diagnosis. For an optimal histopathological assessment, the pathologist is also dependent on the removal of a complete lymph node. Before distinguishing a potentially fatal multicentric idiopathic Castleman's disease from the resectable unicentric form, which is important in terms of prognosis and treatment, early diagnosis presupposes that Castleman's disease is considered in the differential diagnosis. Various immune phenomena and overlaps with autoimmune diseases can increase the probability of misdiagnosis or undetected cases in the clinical routine of rheumatologists. The intention of the present overview is therefore to point out the similarities with autoimmune diseases that are relevant for differential diagnoses and to point out situations that justify a review of the previous diagnosis.

Hodgkin Lymphoma-related Inflammatory Modification-displayed Castleman Disease-like Histological Features and Positron Emission Tomography/Computed Tomography Usefulness for the Differential Diagnosis

Hodgkin lymphoma (HL) and idiopathic multicentric Castleman disease (iMCD) are markedly different conditions. However, in some cases, histological similarities caused by elevated cytokines, including interleukin-6, can lead to a misdiagnosis of HL as Castleman disease (CD). We herein report a patient with HL who had been diagnosed with CD by an expert panel and for whom an additional biopsy was useful for determining the correct diagnosis. Furthermore, we analyzed the positron emission tomography/computed tomography findings at the diagnosis and found that the maximum standardized uptake value was useful for distinguishing HL from iMCD.

Kaposi sarcoma herpesvirus/human herpesvirus 8-positive diffuse large B-cell lymphoma characterized by malignant ascites: A case report

Herein, we report a rare case of Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8)-positive diffuse large B-cell lymphoma (DLBCL), which is characterized by malignant ascites and complex karyotypes. A 72-year-old male patient who tested negative for human immunodeficiency virus presented with thrombocytopenia and lymphadenopathies. He was diagnosed with KSHV/HHV8-associated multicentric Castleman disease (MCD). After three years, he developed progressive lymphadenopathies and massive ascites. The lymphoma cells in the ascitic fluid presented with characteristic immunophenotype and monoclonality, which support the diagnosis of KSHV/HHV8-positive DLBCL. Lymphadenopathies and massive splenomegaly are common manifestations of KSHV/HHV8-positive DLBCL. Nevertheless, peritoneal involvement, as observed in this case, is a rare presentation. This emphasizes the diagnostic complexities of KSHV/HHV8-associated lymphoproliferative disorders. Within the context of preexisting KSHV/HHV8-associated multicentric Castleman disease, the differential diagnosis of this disorder can be challenging.

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

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.

The Cytokine Storm of Multicentric Castleman Disease

As described throughout this book, different triggers can elicit a variety of different cytokine storm disorders that share overlapping clinical features (Fig. 31.1). Even within a particular cytokine storm disorder, multiple different triggers can elicit the syndrome. Like HLH, multicentric Castleman disease (MCD) serves as a great example of this as it can be caused by a viral infection, neoplastic cell population, or an unknown cause. Furthermore, the idiopathic subtype of MCD (iMCD) provides one of the first examples of a cytokine storm disorder that could be abrogated with targeted neutralization of a single cytokine when inhibition with the anti-interleukin-6 (IL-6) receptor monoclonal antibody tocilizumab was shown to effectively treat iMCD in the 1990s. Of course, this "iMCD treatment," tocilizumab, has been used in a variety of cytokine storm settings over the last 30+ years.

Clinical features and treatment outcomes of Castleman disease in children: a retrospective cohort in China

Castleman disease (CD) is a rare lymphoproliferative disorder of undetermined etiology. Unicentric CD (UCD) and multicentric CD (MCD) are two phenotypes of CD diagnosed by the histopathology of lymph nodes. We attempted to describe a pediatric CD cohort to optimize the management of this disease. We reviewed the medical records of pediatric patients diagnosed with CD between April, 2004, and October, 2022, at the Children's Hospital of Fudan University. Prognosis information was collected in January, 2023, by telephone inquiry. Twenty-two patients with UCD and 2 patients with MCD were identified, all with hyaline vascular (HV) type. The median ages at diagnosis were 10.75 years (IQR 8, 12.81) for UCD and 14.42 years (IQR 13.42, 15.42) for MCD. The most common lesion location of UCD was the neck (9/22, 40.91%) and abdomen (9/22, 40.91%). Systematic symptoms occurred on 10/22 (45.45%) patients with UCD and 1/2 (50%) patients with MCD, and abnormal laboratory indexes were detected in both. Resection and biopsy were performed on all patients. One out of two patients with MCD also received rituximab for upfront therapy. After a median of 4 years (IQR 1.5, 6) of follow-up time, the overall survival was 100% and the complete remission rate in UCD was 63%. There was no relapse or progression.

CONCLUSIONS

Our series demonstrated that HV-UCD was the most common type in children. Resection and biopsy were used for both deterministic diagnoses and treatments. Despite the high possibility to develop systematic inflammation, children with CD showed promising outcomes.

WHAT IS KNOWN

• Castleman disease is a rare lymphoproliferative disorder with limited cohort studies, especially in pediatrics. • The ubiquity of delayed confirmations and misdiagnoses points to a lack of knowledge about etiology and characteristics, which is a prerequisite for novel therapeutics.

WHAT IS NEW

• We retrospectively reviewed and analyzed the clinical and pathological symptoms, laboratory and imaging features, and treatment outcomes of a Chinese pediatric cohort with Castleman disease. • Our work may improve the recognition and optimize the management of this rare disease in children.

Idiopathic multicentric castleman's disease mimicking immunoglobulin G4-related disease responding well to Bortezomib: a case report

BACKGROUND

Castleman's disease (CD) is a rare disease that has clinical and pathological similarities to lymphoma and is characterized by a high frequency of associated immunological dysfunction. ImmunoglobulinG4-related disease (IgG4-RD) is a collection of systemic disorders that affect numerous organs and are also referred to as IgG4-associated sclerosing diseases. CD and IgG4-RD are difficult to separate because they may manifest similar commin clinical features.

CASE PRESENTATION

This case describes a 53-year-old female who, during routine medical check-up, exhibited a progressive increase in serum globulin levels and a simultaneous worsening of anemia symptoms, raising concern for a clonal plasma cell disease such as myeloma. However, bone marrow punctures did not reveal any abnormal plasma cells. Also, serum and urine immunofixation electrophoresis demonstrated no abnormal monoclonal protein bands. In addition, several laboratory findings excluded chronic liver disease, chronic infections caused by bacteria or viruses. Later, we found elevated serum IgG4 levels (10,700 mg/L), and identified multiple enlarged lymph nodes throughout the patient's body. Axillary lymph node aspiration revealed no abnormal lymphocytes, ruling out the possibility of lymphoma. Pathological morphology of the axillary lymph revealed a large number of plasma cells in the lymphatic follicles. In addition, there was a reduction in lymphatic follicle size and apoptosis of the germinal centres. Immunohistochemistry revealed IgG4+/IgG + in > 40% of cells, and more than 100 IgG4 + cells per high powered field (HPF) of specimen. As of now, finding strongly suggested IgG4-RD. This patient was treated with glucocorticoids and various immunosuppressive drugs, such as prednisone, cyclosporine, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine and hydroxychloroquine. Unfortunately, the patient did not recover. Ultimately, idiopathic multicentric Castleman disease (iMCD) was diagnosed in relation to the patient's clinical presentation and laboratory tests, and after combination chemotherapy (VCD: Bortezomib, Cyclophosphamide and Dexamethasone), durable remission was achieved without serious adverse effects. During the follow-up period of one year and ten months, the patient remained stable.

CONCLUSION

The diagnosis of Castleman must be distinguished from other disorders such as IgG4-RD, malignant lymphoma, reactive hyperplasia of various lymph nodes (mostly caused by viral infections), plasmacytoma, advanced HIV and rheumatic diseases. Besides observing systemic symptoms, laboratory tests such as immunoglobulin levels, complement levels, interleukin levels, and C-reactive protein levels should also be performed in order to determine a diagnosis.

Higher rate of progression in HIV- than in HIV+ patients after rituximab for HHV8+ multicentric Castleman disease

Rituximab has revolutionized the treatment of Kaposi sarcoma-associated herpesvirus/human herpesvirus 8-associated multicentric Castleman disease (HHV8+ MCD), converting a rapidly fatal illness into a relapsing disease. HHV8+ MCD mainly affects patients with HIV infection but can also be observed in patients without HIV infection. We retrospectively analyzed a cohort of 99 patients (73 who tested HIV+ and 26 who tested HIV-), with HHV8+ MCD treated with rituximab-based therapy. Baseline characteristics were similar in patients who had HIV- and HIV+ results, although those who tested HIV- were older (65 vs 42 years) and presented less frequently with Kaposi sarcoma (15% vs 40%). Ninety-five patients (70 HIV+ and 25 HIV-) achieved complete remission (CR) after rituximab-based therapy. After a median follow-up of 51 months, 36 patients (12 HIV- and 24 HIV+) experienced disease progression. The 5-year progression-free survival (PFS) was 54%. The 5-year PFS was lower in HIV- patients than in HIV+ patients : 26% and 62%, respectively (P = .02). A multivariate prognostic factors analysis including time-dependent covariates revealed that HIV- status, reoccurrence of HHV8 DNA >3 log copies per mL, and serum C-reactive protein (CRP) >20 mg/mL were independently associated with an increased risk of progression after rituximab-induced CR (P = .001; P = .01; and P = .01, respectively). The lower rate of progression observed in the population with HIV+ results despite a longer follow-up period might have resulted from the possible immune restoration upon antiretroviral therapy. HHV8 viral load and serum CRP monitoring after rituximab therapy provide information on the progression risk and may help in the decision to resume specific therapy.

Unicentric Castleman's disease associated with malignant cardiac Amyloid-A amyloidosis: a case report

Background

Unicentric Castleman's disease (UCD), a lymphoproliferative disorder characterized by enlargement of the lymph nodes, is a rare cause of Amyloid-A amyloidosis. While patients usually present with impaired kidney function and proteinuria, heart involvement is neither common nor the main cause of signs and symptoms.

Case summary

We present a patient who was admitted to the hospital for impaired exercise capacity. Diagnostic work-up revealed severe left ventricular hypertrophy suggestive of cardiac amyloidosis. Although Congo red staining of endomyocardial biopsies was initially negative, subsequent immunohistochemical staining against serum amyloid A finally confirmed the diagnosis of cardiac amyloidosis. 18F-fluorodeoxyglucose positron emission tomography/computed tomography revealed a tumour located in dorsal of the duodenum. Fine-needle aspiration biopsy of the tumour was suggestive but could not confirm the presence of UCD beyond reasonable doubt. Rapid worsening of heart failure symptoms warranted urgent surgical tumourectomy, which resulted in immediate post-operative lowering of serum amyloid protein. However, post-operative cardiogenic shock could not be stabilized even with veno-arterial extracorporeal membrane oxygenation, and the patient eventually died. The UCD of the hyaline vascular (HV) subtype was confirmed by pathologic work-up of the excised tumour.

Discussion

This case report presents for the first time a patient with malignant cardiac Amyloid-A amyloidosis caused by unicentric Castleman's disease of the HV subtype. Since the disease progresses swiftly, rapid diagnosis is essential for potential curative treatment.

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.

Imaging of Castleman Disease

Castleman disease (CD) is a group of rare and complex lymphoproliferative disorders that can manifest in two general forms: unicentric CD (UCD) and multicentric CD (MCD). These two forms differ in clinical manifestation, imaging appearances, treatment options, and prognosis. UCD typically manifests as a solitary enlarging mass that is discovered incidentally or after development of compression-type symptoms. MCD usually manifests acutely with systemic symptoms including fever and weight loss. As a whole, CD involves lymph nodes throughout the chest, neck, abdomen, pelvis, and axilla and can have a wide variety of imaging appearances. Most commonly, lymph nodes or masses in UCD occur in the chest, classically with well-defined borders, hyperenhancement, and possible characteristic patterns of calcification and/or feeding vessels. Lymph nodes affected by MCD, while also hyperenhancing, tend to involve multiple nodal chains and manifest alongside anasarca or hepatosplenomegaly. The polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) subtype of MCD may demonstrate lytic or sclerotic osseous lesions in addition to features typical of MCD. Since a diagnosis of CD based solely on imaging findings is often not possible, pathologic confirmation with core needle biopsy and/or surgical excision is necessary. Nevertheless, imaging plays a crucial role in supporting the diagnosis of CD, guiding appropriate regions for biopsy, and excluding other potential causes or mimics of disease. CT is frequently the initial imaging technique used in evaluating potential CD. MRI and PET play important roles in thoroughly evaluating the disease and determining its extent, especially the MCD form. Complete surgical excision is typically curative for UCD. MCD usually requires systemic therapy. ^©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

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.

Multicentric Castleman disease of hyaline‑vascular variant with paraneoplastic pemphigus results in abnormal lung function: Report of 3 cases

Castleman disease (CD) is clinically divided into unicentric CD (UCD) and multicentric CD (MCD). Hyaline-vascular variant (HV) is the most common pathological type of UCD, while the plasma cell type (PC) is the most common type of MCD and thus, hyaline-vascular variant multicentric CD (HV-MCD) is a rare type of CD. In addition, its etiology has remained elusive. The present study retrospectively analyzed the medical records of 3 patients diagnosed as HV-MCD admitted to The First Affiliated Hospital of Guangxi Medical University (Guangxi, China) between January 2007 and September 2020. A total of 2 males and 1 female were admitted. The areas involved varied considerably. Respiratory symptoms were seen in 3 cases, along with fever, weight loss and splenomegaly. Damage to the skin and mucous membranes resulted in oral ulcers when accompanied by paraneoplastic pemphigus (PNP). Dry and wet rales were found in all patients. All 3 cases were complicated with PNP and had hypoxemia and obstructive ventilation dysfunction. In accordance with PC-MCD, it manifested as lymph node enlargement and may involve several lymph nodes. Computed tomography mainly indicated bronchiectasis and mediastinal lymph node enlargement. In 1 case, chemotherapy failed after local mass excision, 1 case remitted after chemotherapy but the lung lesion was irreversible and 1 case was untreated and soon died of respiratory failure. The cases of HV-MCD with pulmonary involvement were induced by small airway lesions and associated with poor prognosis. Respiratory symptoms along with systemic symptoms were common.

Unmet Clinical Needs in the Management of Idiopathic Multicentric Castleman Disease: A Consensus-based Position Paper From an ad hoc Expert Panel

Castleman disease describes a group of heterogeneous clinicopathological disorders now included in the tumor-like lesions with B-cell predominance of the World Health Organization classification. Managing idiopathic multicentric Castleman disease (iMCD) is challenging, because few systematic studies or comparative randomized clinical trials have been conducted. International, consensus evidence-based guidelines for iMCD were published in 2018, but gaps in the therapeutic options for difficult-to-treat patients, who do not respond to siltuximab and other conventional therapies, still exist. This article presents the results of group discussion among an ad hoc constituted Panel of Italian experts to identify and address unmet clinical needs (UCNs) in managing iMCD. Recommendations on the appropriateness of clinical decisions and proposals for new research concerning the identified UCNs were issued through formalized multiple-step procedures after a comprehensive analysis of the scientific literature. The following key UCNs were addressed: strengthening the diagnostic certainty in iMCD patients before planning first-line therapy; management of siltuximab therapy; choice and management of immune-modulating, or chemotherapy agents in patients resistant/intolerant to siltuximab therapy. While most of the conclusions reached by the Panel are consistent with the existing guidelines, some alternative therapeutic options were stressed, and the discussion contributed to bringing forth the issues that need further investigation. Hopefully, this comprehensive overview will improve the practice of iMCD and inform the design and implementation of new studies in the field.

Paraneoplastic pemphigus uncovers distinct clinical and biological phenotypes of western unicentric Castleman disease

Unicentric Castleman disease (UCD) is a lymphoproliferative disease of unknown cause. Paraneoplastic pemphigus (PNP) is a major complication shown to be associated with a poor prognosis, with particular severity in patients with bronchiolitis obliterans (BO). This study describes the clinical and biological characteristics of UCD-PNP patients in a large Western cohort. A total of 148 patients diagnosed with UCD were identified, including 14 patients with a defined PNP. PNP was significantly associated with myasthenia gravis (MG) and FDC sarcoma during follow-up (FDCS). PNP was also significantly associated with reduced survival. These data, together with a multivariate analysis by principal components, led to the identification of UCD-PNP as a group at risk of MG, FDCS and death. PDGFRB sequencing performed on UCD lesions from six patients found the gain-of-function p.N666S variant in two. Interestingly, both patients had hyaline-vascular UCD subtype, were in the UCD-PNP subgroup and had FDCS. Sera from 25 UCD-PNP patients and 6 PNP patients without UCD were tested for PNP-associated autoantibodies. Sera from UCD-PNP patients had a strong reactivity against the N-terminal domain of recombinant periplakin (rPPL, 82%) and showed reactivity against at least two domains of rPPL. These features were not found in patients with UCD alone or in the PNP group without UCD. These data indicate that UCD-PNP patients belong to a subgroup sharing strong clinical and biological identity that might help to decipher the different dynamics of UCD natural history.

Castleman's disease: A report of two cases at a tertiary hospital in Northern Tanzania

Castleman's disease is a rare lympho-proliferative disease entity characterized by variable clinical presentations, distinctive histological manifestations, and prognosis. Its incidence and etiology are unclear. An interplay of HIV and human herpesvirus-8 has been implicated. Although its localized variety is benign, other types can be multifocal with adverse systemic manifestations. Human herpesvirus-8 Castleman's disease affects mainly HIV-positive individuals; however, individuals who are immunocompromised from other causes can also be affected, thus necessitating investigations for HIV. Herein, we report two patients presenting with long-standing lymphadenopathy. Histopathology, immunohistochemical testing and clinico-pathological correlation confirmed the diagnosis of Castleman's disease. The patients were successfully treated with surgery and/or rituximab. They were symptoms free in the subsequent follow-up visits. A brief review of the literature is also provided.

A national, multicenter, retrospective study of Castleman disease in China implementing CDCN criteria

BACKGROUND

Castleman disease (CD) is a group of rare and heterogenous lymphoproliferative disorders including unicentric CD (UCD), human herpesvirus-8(HHV-8)-associated multicentric CD (HHV8-MCD), and HHV-8-negative/idiopathic multicentric CD (iMCD). Knowledge of CD mainly comes from case series or retrospective studies, but the inclusion criteria of these studies vary because the Castleman Disease Collaborative Network (CDCN) diagnostic criteria for iMCD and UCD were not available until 2017 and 2020, respectively. Further, these criteria and guidelines have not been systematically evaluated.

METHODS

In this national, multicenter, retrospective study implementing CDCN criteria, we enrolled 1634 CD patients (UCD, n = 903; MCD, n = 731) from 2000 to 2021 at 40 Chinese institutions to depict clinical features, treatment options, and prognostic factors of CD.

FINDINGS

Among UCD, there were 162 (17.9%) patients with an MCD-like inflammatory state. Among MCD, there were 12 HHV8-MCD patients and 719 HHV-8-negative MCD patients, which included 139 asymptomatic MCD (aMCD) and 580 iMCD meeting clinical criteria. Of 580 iMCD patients, 41 (7.1%) met iMCD-TAFRO criteria, the others were iMCD-NOS. iMCD-NOS were further divided into iMCD-IPL (n = 97) and iMCD-NOS without IPL (n = 442). Among iMCD patients with first-line treatment data, a trend from pulse combination chemotherapy toward continuous treatment was observed. Survival analysis revealed significant differences between subtypes and severe iMCD (HR = 3.747; 95% CI: 2.112-6.649, p < 0.001) had worse outcome.

INTERPRETATION

This study depicts a broad picture of CD, treatment options and survival information in China and validates the association between the CDCN's definition of severe iMCD and worse outcomes, requiring more intensive treatment.

FUNDINGS

Beijing Municipal Commission of Science and Technology, CAMS Innovation Fund and National High Level Hospital Clinical Research Funding.

T-Cells Subsets in Castleman Disease: Analysis of 28 Cases Including Unicentric, Multicentric and HHV8-Related Clinical Forms

Castleman disease (CD) is a rare lymphoproliferative disorder that includes various clinico-pathological subtypes. According to clinical course, CD is divided into unicentric CD (UCD) and multicentric CD (MCD). MCD is further distinguished based on the etiological driver in herpes virus-8-related MCD (that can occur in the setting of HIV); in MCD associated with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes); and idiopathic MCD (iMCD). The latter can also be divided in iMCD-TAFRO (thrombocytopenia, anasarca, fever, myelofibrosis, organomegaly) and iMCD not otherwise specified. To date, CD pathogenesis is still uncertain, but CD may represent the histological and clinical result of heterogeneous pathomechanisms. Transcriptome investigations in CD lymph nodes have documented the expression and up-regulation of different cytokines; furthermore, few recent studies have shown alterations of different T-cell subsets in CD patients, suggesting a possible role of the nodal microenvironment in CD development. On this basis, our study aimed to investigate the distribution of T-cell subsets in the clinico-pathological spectrum of CD. We evaluated the CD4/CD8 ratio and the number of T-regulatory (T-reg) FOXP3+ cells in 28 CD cases. In total, 32% of cases showed a decreased CD4/CD8 ratio due to increased CD8+ T-cells, including both UCD, iMCD, and HHV8+ MCD cases. The T-reg subset analysis revealed a statistically significant (p < 0.0001) lower mean number of FOXP3+ T-reg cells in CD cases when compared with non-specific reactive lymph nodes. We did not find statistically significant differences in T-reg numbers between the different CD subtypes. These findings may suggest that alterations in T-cell subpopulations that can lead to disruption of immune system control may contribute to the numerous changes in different cellular compartments that characterize CD.

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.

Clinical and histopathology characteristics of Castleman disease: a multicenter study of 51 Brazilian patients

Castleman's disease (CD) is a rare and heterogeneous lymphoproliferative disorder, with limited available clinical information in Brazil. A retrospective study was carried out through information contained in the medical records of 51 patients, between July 1999 and June 2020. Seven patients were excluded, and 44 were analyzed in total. The average age of unicentric CD (UCD) patients was 35 years old and of multicentric CD (MCD) patients was 49 years old (p = 0.013). Regarding gender, there was a predominance of females among patients with UCD (68.4%) and males in patients with MCD (57.9%) (p = 0.103). The most common site of involvement in UCD was the cervical region (36.8%). A total of 73.7% of patients with UCD and 68.4% of patients with MCD presented the histological form hialyne-vascular (HV) (p = 0.499). Most patients with laboratory abnormalities had MCD. A total of 78% of the patients were asymptomatic, with the majority of symptomatic patients with MCD (p = 0.042). Only two of the 27 patients evaluated for the presence of human immunodeficiency virus (HIV) had positive serology. HHV-8 was evaluated in 14 cases, being positive in two. Of the patients with UCD, 94.7% underwent excisional biopsy, against only 41.2% of patients with MCD (p = 0.01). The mean follow-up was 61 months. We observed similarities in the clinical profile between patients in our study and patients described in the literature, such as gender, mean age, B symptoms, visceromegaly, fluid accumulation, and treatment. Unlike the literature, the cervical region was the most affected site, besides the greater association of the HV histological subtype among patients with MCD.

Case report: Importance of early and continuous tocilizumab therapy in nephrotic syndrome associated with idiopathic multicentric Castleman disease: A case series

Idiopathic multicentric Castleman disease (iMCD) is a systemic and polyclonal lymphoproliferative disease involving multiple organs, including the kidneys, due to the overproduction of interleukin-6 (IL-6). Recently, several reports have suggested that excessive IL-6 actions in iMCD could have a causal relationship with the development of diverse histopathological renal manifestations that cause nephrotic syndrome. However, the treatment for such cases remains unclear. We report a series of three cases of nephrotic syndrome due to iMCD that helps to delineate the importance of early and continuous therapy with the anti-interleukin-6 receptor antibody tocilizumab. First, treatment was suspended for infectious control, and the patient presented with nephrotic syndrome due to diffuse mesangial and endocapillary hypercellularity without immune deposits complicating acute kidney injury. Second, iMCD was treated with prednisolone alone. The patient suddenly developed nephrotic syndrome due to immune-complex glomerulonephritis, not otherwise specified, complicated with acute kidney injury. In the third case, nephrotic syndrome secondary to membranous glomerulonephritis was diagnosed, with a skin rash and IgE antibodies to tocilizumab, and was therefore treated with prednisolone alone. In contrast to the first two cases, the third progressed to end-stage renal disease on hemodialysis. Taken together, this series suggests that clinicians should maintain clinical vigilance for iMCD as a possible underlying component of nephrotic syndrome, since iMCD presents with a variety of renal pathologies. Prompt initiation and continuous administration of tocilizumab are likely key determinants of renal outcomes in such cases. In particular, when tocilizumab is suspended due to infection or in the perioperative period, consideration of its expeditious resumption should be made, taking into account both the withdrawal period and systemic conditions.