Castleman Disease

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.

Urologic Presentation of Unicentric Pediatric Castleman Disease in the Setting of Acute Renal Colic

An 11-year-old otherwise healthy female presented with renal colic and during computed tomography imaging evaluation, she was found to have a right distal ureteral stone with associated hydroureteronephrosis, medially deviated ureter, and 4-cm solid retroperitoneal mass. The mass was palpable on physical exam and was further categorized with magnetic resonance imaging, ultrasound, and laboratory testing. A multidisciplinary team approach, including pediatric surgery, radiology, oncology, and urology, led to the patient undergoing a right retrograde pyelogram, ureteroscopy with stent placement, and laparoscopic excision of retroperitoneal mass. Her pathology revealed lymphoid hyperplasia with histologic features of Castleman disease.

Fifth Edition of the World Health Classification of Tumors of the Hematopoietic and Lymphoid Tissues: B-cell Neoplasms

We review B-cell neoplasms in the 5th edition of the World Health Organization classification of hematolymphoid tumors (WHO-HEM5). The revised classification is based on a multidisciplinary approach including input from pathologists, clinicians, and other experts. The WHO-HEM5 follows a hierarchical structure allowing the use of family (class)-level definitions when defining diagnostic criteria are partially met or a complete investigational workup is not possible. Disease types and subtypes have expanded compared with the WHO revised 4th edition (WHO-HEM4R), mainly because of the expansion in genomic knowledge of these diseases. In this review, we focus on highlighting changes and updates in the classification of B-cell lymphomas, providing a comparison with WHO-HEM4R, and offering guidance on how the new classification can be applied to the diagnosis of B-cell lymphomas in routine practice.

Primary hepatic Castleman disease

Castleman disease (CD) is a rare, benign lymphoproliferative disorder with characteristic histopathological features, but variable aetiology, presentation, treatment and prognosis. It is broadly classified based on its location and histopathological features, with unicentric hyaline vascular disease presenting most commonly. We present a case of primary, unicentric hepatic CD that was incidentally found on imaging and managed with laparoscopic resection.

Unicentric Castleman Disease: Illustration of Its Morphologic Spectrum and Review of the Differential Diagnosis

CONTEXT.—

Unicentric Castleman disease (UCD) is a dynamic entity with a wide spectrum of morphologic findings. UCD can be further subdivided into hyaline-vascular and mixed/plasmacytic variants. Hyaline-vascular UCD has both follicular and interfollicular (stromal) changes, and occasionally these lesions show a skewed representation of either the follicular or stromal compartments. Plasmacytosis is usually minimal in the hyaline-vascular variant. The mixed/plasmacytic variant of UCD is composed of sheets of plasma cells often associated with a variable number of follicles with regressive changes.

OBJECTIVE.—

To illustrate the differential diagnosis of UCD, as it is quite broad and includes lymphomas, plasma cell neoplasms, stromal neoplasms such as follicular dendritic cell sarcoma and vascular neoplasms, immunoglobulin G4-related disease, infections, and other rare lesions. An additional objective is to enhance awareness of the morphologic features of UCD in excisional and in small core-needle biopsy specimens, the latter of which may inadvertently target follicle- or stroma-rich areas, causing diagnostic challenges.

DATA SOURCES.—

In this review, we provide readers a concise illustration of the morphologic spectrum of UCD that we have encountered in our practice and a brief discussion of entities in the differential diagnosis.

CONCLUSIONS.—

UCD exhibits a broad spectrum of morphologic changes, and awareness of these morphologic variations is key to avoid misdiagnosis.

Mesenteric Castleman Disease Misdiagnosed as Lymph Node Metastasis of Rectal Cancer on 18 F-FDG PET/CT

ABSTRACT

Two years ago, a 64-year-old man underwent an 18 F-FDG PET/CT for staging rectal cancer. Besides the hypermetabolic rectal lesion, the image revealed a mesenteric lymph node with intense activity and multiple lung nodules with slight FDG uptake, which were highly suspected of metastases. After surgery and multiple cycles of chemotherapy, the follow-up 18 F-FDG PET/CT showed remission of all lesions except for the enlarged mesenteric lymph node with higher metabolic activity. Serum CEA remained normal during the follow-up. Postoperative pathology of the mesenteric lymph node confirmed Castleman disease.

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.

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.

From the archives of MD Anderson Cancer Center Castleman disease involving the thymus gland: Case report and literature review

Castleman disease is a nodal based disease and very rarely involves the thymus gland. We report a 52-year-old man who was found incidentally to have a single thymic mass by computerized tomography scan. Thymectomy was performed, and the gross specimen showed a well-circumscribed, multi-loculated cystic mass. Histologic examination showed thymus involved by Castleman disease, hyaline-vascular variant. The lesion was characterized by lymphoid follicles with wide mantle zones, variably lymphocyte-depleted germinal centers with sclerotic radial blood vessels, and prominent interfollicular/stromal changes including numerous endothelial venules with sclerotic walls and hyaline sclerosis, scattered and frequent dysplastic follicular dendritic cells and foci of dystrophic calcification. Immunohistochemical analysis showed that the follicle mantle zones were composed of numerous B-cells positive for CD20, PAX5, and IgD. Antibodies specific for CD21 and CD23 highlighted prominent follicular dendritic cell networks within follicles. There was no evidence of human herpes virus 8. We searched the literature and could identify only 10 additional cases of thymic CD. Previously reported cases included 8 unicentric and 2 multicentric, classified pathologically as plasma cell variant (n = 4), hyaline vascular variant (n = 3), and mixed (n = 3). Thymectomy, as was done in the currently reported case, most often leads to the diagnosis of Castleman disease and was a mainstay of treatment in other reported cases.

Novel Molecular Therapies and Genetic Landscape in Selected Rare Diseases with Hematologic Manifestations: A Review of the Literature

Rare diseases affect less than 1 in 2000 people and are characterized by a serious, chronic, and progressive course. Among the described diseases, a mutation in a single gene caused mastocytosis, thrombotic thrombocytopenic purpura, Gaucher disease, and paroxysmal nocturnal hemoglobinuria (KIT, ADAMTS13, GBA1, and PIG-A genes, respectively). In Castleman disease, improper ETS1, PTPN6, TGFBR2, DNMT3A, and PDGFRB genes cause the appearance of symptoms. In histiocytosis, several mutation variants are described: BRAF, MAP2K1, MAP3K1, ARAF, ERBB3, NRAS, KRAS, PICK1, PIK3R2, and PIK3CA. Genes like HPLH1, PRF1, UNC13D, STX11, STXBP2, SH2D1A, BIRC4, ITK, CD27, MAGT1, LYST, AP3B1, and RAB27A are possible reasons for hemophagocytic lymphohistiocytosis. Among novel molecular medicines, tyrosine kinase inhibitors, mTOR inhibitors, BRAF inhibitors, interleukin 1 or 6 receptor antagonists, monoclonal antibodies, and JAK inhibitors are examples of drugs expanding therapeutic possibilities. An explanation of the molecular basis of rare diseases might lead to a better understanding of the pathogenesis and prognosis of the disease and may allow for the development of new molecularly targeted therapies.

[Castleman disease]

The term "Castleman disease" covers a variety of entities that have very different clinical, biological, pathological and physiopathological features. In this issue, we review the characteristics of the unicentric Castleman disease, of the HHV8 associated multicentric Castleman disease and the idiopathic multicentric Castleman disease associated or not with TAFRO syndrome ("thrombocytopenia, anasarca, fever, reticulin myelofibrosis and/or renal insufficiency, organomegaly"). We detail the differential diagnostics of these entities.

The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5^th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4^th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5^th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

KSHV/HHV8-mediated hematologic diseases

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

Castleman Disease with MDM2/CDK4 Protein Expression: a Potential Mimic of Inflammatory Variant of Liposarcoma with Significant Consequences

Castleman disease is a rare benign lymphoproliferative disorder that includes a spectrum of distinct histopathological entities. The differential diagnosis of Castleman disease is broad and includes lymphomas, HIV-related lymphadenopathy, autoimmune disorders, and inflammatory liposarcoma. When Castleman disease occurs in the retroperitoneum, the distinction from the inflammatory variant of well-differentiated liposarcoma can be very challenging in small biopsies. Herein we report a case of Castleman disease that presented as a retroperitoneal mass and expressed MDM2 and CDK4 by immunohistochemistry. To our knowledge, this is the first report of Castleman disease staining positively for MDM2/CDK4, and it underscores how immunohistochemistry can potentially serve as a pitfall when differentiating this rare entity from retroperitoneal sarcomas.

Epstein-Barr virus reactivation influences clonal evolution in human herpesvirus-8-related lymphoproliferative disorders

Background

Human herpesvirus‐8 (HHV8) is a lymphotropic virus associated with different lymphoproliferative disorders, including primary effusion lymphoma (PEL), multicentric Castleman’s disease (MCD), diffuse large B‐cell lymphomas, not otherwise specified, and the rare entity known as germinotropic lymphoproliferative disorder (GLPD). In PELs and GLPD the neoplastic cells also contain Epstein–Barr virus (EBV). In addition, occasional cases with atypical and overlapping features among these entities have been recognised, suggesting that the spectrum of the HHV8‐related lesions may not be fully characterised.

Aims

Here, we report two cases of lymphoproliferative disorder associated with HHV8 and EBV that further expand the spectrum of HHV8/EBV‐positive lymphoproliferative disease.

Methods and results

Case 1 represented HHV8/EBV‐positive extracavitary nodal PEL followed by pleural PEL. The striking characteristic of this case was the almost focal and intrasinusoidal localisation of the neoplastic cells and the association with Castleman’s disease features. In the second case, we found the entire spectrum of HHV8‐related disorders, i.e. MCD, GLPD, and PEL, coexisting in the same lymph node, underlining the variability, possible overlap and evolution among these entities. Both cases were well analysed with immunohistochemistry, determination of the EBV latency programme, and molecular analysis for clonality of immnoglobulin genes. In both patients, the disease followed an unexpected indolent course, both being still alive after 8 and 12 months, respectively.

Conclusion

Our findings represent further evidence of the overlap among HHV8/EBV‐positive lymphoproliferative disorders, and underline a grey zone that requires further study; they further confirm the experimental evidence that lytic EBV replication influences HHV8‐related tumorigenesis.

Castleman's disease masquerading as pancreatic neuroendocrine tumour

Castleman's disease (CD) is a rare lymphoproliferative disorder. This case report, to the best of our knowledge, is the first report of CD simulating a pancreatic neuroendocrine tumour . The patient was a 58-year-old woman who initially presented with bilateral iritis and underwent investigation for possible systemic rheumatological disease. CT of the chest demonstrated an incidental finding of a well-demarcated retropancreatic mass. As the mass was found to enhance on DOTATATE (tetraazacyclododecanetetraacetic acid-DPhe1-Tyr3-octreotate) positron emission tomography, a diagnosis of pancreatic neuroendocrine tumour was made. The patient underwent an open distal pancreatectomy and splenectomy. Histopathological examination revealed the unexpected diagnosis of hyaline vascular CD of a lymph node posterior to the pancreas. After 2 years of follow-up, there is no evidence of disease recurrence.

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.

Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997

Clinical Analysis of Castleman's Disease of the Lacrimal Gland

Objective

To explore the clinical manifestations, imaging characteristics, and pathological characteristics of Castleman's disease of the lacrimal gland, enhance the knowledge of the disease, and improve the level of its diagnosis and treatment.

Methods

In the retrospective study, the data of 5 patients diagnosed with Castleman's disease of the lacrimal gland in Tianjin Medical University Eye Hospital from 2014 to 2018 were analyzed, and the relevant literature was reviewed.

Results

All the 5 patients were confirmed by pathological examination. Clinical manifestations were characterized by mass occupying lesions in the lacrimal gland area, without obvious pain, accompanied by eyelid swelling and ptosis, as well as space-occupying symptoms. Imaging examination showed that there was a soft tissue mass in the enlarged lacrimal gland area, and the mass was rich in blood flows while showing no obvious specificity, which could invade the surrounding muscles. All patients underwent surgical resection. Pathological results showed that 1 case was of the hyaline-vascular type, 3 cases were of the plasma cell type, and 1 case showed malignant transformation to plasma cell tumor.

Conclusion

Castleman's disease of the lacrimal gland is a rare orbital lymphoproliferative disease lacking specificity in clinical manifestations and imaging examination. As there are difficulties in differentiating the disease from orbital inflammatory pseudotumor and orbital lymphoma, its diagnosis still depends on pathological examination. The disease is mainly treated with surgical resection, and the pathological type is determined postoperatively.

A lymphoproliferative pericardial mass

Castleman disease (CD) is a rare lymphoproliferative disorder with variable presentation and prognosis. Most CD cases are unicentric and correspond to the hyaline-vascular variant, a histopathological classification associated with better outcomes, which commonly presents as an enhancing hypervascular mediastinal mass. CD is often asymptomatic and surgically resectable. Nonetheless, surgical resection can be difficult when the lymphoid mass is causing compression of vital structures. We discuss a rare case of hyaline-vascular unicentric CD presenting as an incidental pericardial mass.

Non-neoplastic conditions mimicking peritoneal carcinomatosis at CT imaging

The general appearance of peritoneal carcinomatosis at abdominal CT and other cross-sectional imaging modalities consists of varying amounts of peritoneal-based soft tissue implants (mass-forming or infiltrative), peritoneal fluid, and occasionally calcification. However, a wide variety of common and uncommon neoplastic and non-neoplastic conditions can closely mimic peritoneal carcinomatosis at imaging. Neoplastic mimics of peritoneal carcinomatosis include primary peritoneal and sub peritoneal tumors, as well as peritoneal lymphomatosis and sarcomatosis.Broad categories of non-neoplastic mimics of peritoneal carcinomatosis include tumor-like conditions, systemic processes, atypical infections, and fat-based conditions. For many entities, suggestive or specific patient information and/or CT imaging findings exist that may allow the radiologist to narrow the differential diagnosis. In this article, we review the salient clinical and cross-sectional imaging features of non-neoplastic mimics of peritoneal carcinomatosis and malignancy, with emphasis on the CT findings and the additional clues that may suggest the correct benign diagnosis.

Afebrile Pneumonia in a Patient With Multicentric Castleman Disease on Siltuximab: Infection Without Fever on Anti-Interleukin-6 Therapy

Castleman disease is a lymphoproliferative disorder characterized by atypical lymph node hyperplasia and systemic symptoms; it can also affect the skin and blood counts. The condition is categorized by the extent of involvement (unicentric or multicentric) and the observed lymph node pathology (hyaline-vascular, plasma cell or mixed cellularity). Pathogenesis also has a role in the classification and treatment of multicentric Castleman disease; this variant can either be related to the presence of human herpesvirus-8 (HHV-8) infection or associated with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal proteins and skin changes) syndrome, or idiopathic. The principal cytokine responsible for causing idiopathic multicentric Castleman disease (IMCD) is interleukin-6 (IL-6). Therefore, treatment with agents that bind to IL-6 (such as siltuximab) or block the IL-6 receptor (such as tocilizumab) has been used. We report a woman with IMCD who was successfully being treated with siltuximab; her cutaneous manifestations and systemic disease (lung and lymph nodes) improved within three months. However, nine months after starting siltuximab, she developed a worsening cough and new infiltrates in the right lung on positron emission tomography/computed tomography (PET/CT) scan; there were no other constitutional symptoms such as fever, night sweats or fatigue. Differential diagnosis included Castleman disease recurrence, lung neoplasm and infection. Her pulmonary symptoms and infiltrates on scan resolved after treatment with systemic levofloxacin, indicating that she had an antibiotic-sensitive afebrile pneumonia. We postulate that her siltuximab therapy blocked the IL-6-associated fever and constitutional symptoms that normally are a hallmark of pneumonia. Therefore, patients who are receiving medications such as siltuximab and tocilizumab that block the IL-6 pathway and impair the acute phase inflammatory response may fail to manifest constitutional symptoms such as fever when infected.

Unexplained cause of thrombocytopenia, fever, anasarca and hypothyroidism: TAFRO syndrome with thrombotic microangiopathy renal histology

TAFRO (thrombocytopenia, anasarca, fever, reticulin myelofibrosis or renal dysfunction and organomegaly) syndrome is a systemic inflammatory disease characterised by thrombocytopenia, anasarca, fever or inflammatory syndrome, reticulin myelofibrosis or renal dysfunction and organomegaly. It was first described as a subtype of idiopathic multicentric Castleman disease. Here, we report the case of a 42-year-old woman presenting with thrombocytopenia, anasarca, inflammatory syndrome, renal insufficiency, reticulin myelofibrosis at bone marrow biopsy and cervical and axillary lymph nodes. Kidney biopsy showed double contours of the glomerular basement membrane, mesangiolysis and endothelial swelling compatible with thrombotic microangiopathy (TMA) as well as with TAFRO syndrome. She was successfully treated by corticosteroids, tocilizumab and rituximab. This new case description of TAFRO syndrome underlines three features of this disease rarely described in the literature and never simultaneously in the same patient: the association to severe hypothyroidism, the presence of TMA-like lesions on kidney biopsy and the treatment by the association of steroids, tocilizumab and rituximab.

Excellent Outcomes with Surgery or Radiotherapy in the Management of Castleman Disease Including a Case of Oligocentric Disease

BACKGROUND

Castleman disease (CD) is a rare polyclonal lymphoproliferative disorder of unclear etiology. Standard therapy for unicentric CD is surgical resection. Radiotherapy can be used; however, its efficacy is poorly characterized.

PATIENTS AND METHODS

We reviewed patients with histologically confirmed CD undergoing definitive local therapy at our institution between 1990 and 2017. Overall survival was determined from the date of diagnosis. Local progression-free survival and distant failure-free survival were determined from the date of first definitive therapy. The Kaplan-Meier method was used to analyze survival.

RESULTS

Forty-four patients (29 female and 15 male) were identified with a median age at diagnosis of 40 years (range, 14-70 years). Thirty-five (80%) patients received surgery alone, 3 (7%) had surgery followed by radiotherapy, and 6 (14%) had radiotherapy alone. Thirty-nine (89%) patients had a single area of involvement, and 3 (7%) patients had limited regional involvement. Two (5%) patients had multicentric CD and received consolidative radiotherapy. The 3-year overall, local progression-free, and distant failure-free survival were 92%, 100%, and 100%, respectively. No distant failures were observed. The median radiation dose was 3960 cGy (range, 3600-5940 cGy) in 22 fractions (range, 18-33 fractions).

CONCLUSIONS

Unicentric CD is readily amenable to cure with local therapy. Surgical excision is preferred, but radiation appears to be an effective alternative for patients when surgery is high risk or not feasible. Patients with oligo- or multi-centric CD may experience prolonged disease-free survival with consolidative radiotherapy after partial response to systemic therapy.

Classic Hodgkin lymphoma and Castleman disease: an entity appears to be emerging

Hodgkin lymphoma is a B cell neoplasm characterized by Hodgkin and Reed-Sternberg (HRS) cells in an inflammatory background. Classic Hodgkin lymphoma (CHL) accounts for approximately 90% of all cases of HL and four types are recognized in the World Health Organization (WHO) classification: lymphocyte-rich, nodular sclerosis, mixed cellularity, and lymphocyte depleted. Castleman disease (CD) is a designation used for a heterogeneous group of diseases that involve lymph nodes. Histologically, there are hyaline vascular and plasma cell variants, the latter including human herpes virus 8 (HHV8)-positive and HHV8-negative subsets. In this study, we describe three men, 45-57 years of age, one HIV-positive, who had coexistent CHL and CD. All patients had the interfollicular variant of CHL and HHV8-negative plasma cell variant CD. Immunohistochemical analysis supported the diagnosis of CHL; the HRS cells were positive for CD15, CD30, and PAX-5 (dim). In two cases, the HRS cells and the plasma cells of CD expressed interleukin-6 (IL-6). Our review of the literature identified 34 cases of coexistent CHL and CD reported previously. In aggregate, about two-thirds of all cases of CHL have been the interfollicular variant and around 90% of CD cases were plasma cell variant, HHV8-negative in the subset of cases tested. We suggest that interfollicular variant CHL and plasma cell variant CD may be a distinct entity with a common pathogenesis, possibly related to IL-6 dysregulation. The few cases in the literature describing other forms of CHL and hyaline vascular variant CD are different from the entity reported here, with a different pathogenesis, likely similar to focal Castleman-like changes that have been described in association with various types of non-Hodgkin lymphoma.