Castleman disease

What is Castleman disease?

Castleman disease is a rare group of disorders affecting the lymph nodes and immune system, characterized by abnormal growth of lymphatic tissue and excessive inflammation throughout the body. The condition can occur as a localized form affecting single lymph nodes or as a more serious multicentric form causing widespread lymph node enlargement and life-threatening complications. Approximately 6,500-7,700 new cases are diagnosed annually in the United States across all types. While some cases are linked to the human herpesvirus-8 (HHV-8), many cases have no identifiable cause, making diagnosis and treatment particularly challenging.

Key statistics

Symptoms

Common symptoms: Enlarged lymph nodes, fatigue, fever, night sweats, weight loss, weakness, skin rash, difficulty breathing, abdominal swelling

Unicentric Castleman disease typically presents with a single enlarged lymph node mass, often in the chest or abdomen, and may cause no symptoms or only localized pressure effects. Patients might experience chest pain, difficulty swallowing, or abdominal discomfort depending on the location.

Multicentric Castleman disease causes more severe, systemic symptoms including multiple enlarged lymph nodes throughout the body, persistent high fevers, drenching night sweats, and severe fatigue. Patients often develop cytopenias (low blood cell counts), leading to anemia, increased infection risk, and easy bruising or bleeding. Fluid retention may cause swelling in the legs, abdomen, or around the lungs. Neurological symptoms can include confusion, weakness, and peripheral neuropathy.

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Additional manifestations may include enlarged liver and spleen, skin changes such as rashes or kaposi sarcoma-like lesions (particularly in HHV-8 positive cases), and autoimmune complications affecting kidneys or other organs.

Causes and risk factors

Castleman disease has multiple potential causes, though many cases remain idiopathic (unknown cause). The multicentric form is often associated with human herpesvirus-8 (HHV-8) infection, particularly in patients with compromised immune systems. This viral connection explains the higher incidence in individuals with HIV/AIDS.

Other cases appear to result from dysregulated immune responses, where the body’s inflammatory pathways become overactive without a clear trigger. Interleukin-6 (IL-6), a key inflammatory protein, plays a central role in disease progression by promoting excessive B-cell proliferation and systemic inflammation.

Risk factors include HIV infection, immunosuppression from organ transplantation or medications, older age, and potentially genetic factors that affect immune regulation. Unlike hereditary cancers, Castleman disease is not passed down through families and shows no clear inheritance pattern.

Prevention

Currently, no established prevention strategies exist for Castleman disease due to its unclear etiology in most cases. Since HHV-8 infection contributes to some cases, maintaining good immune system health and practicing safe behaviors to prevent viral infections may theoretically reduce risk, though this has not been proven.

For individuals with HIV, maintaining optimal viral suppression through antiretroviral therapy may help reduce the risk of developing HHV-8-associated Castleman disease. Regular medical care and prompt treatment of infections can support overall immune function.

Genetic testing is not applicable since Castleman disease is not inherited, and no screening tests exist for early detection in asymptomatic individuals.

Complications

Without treatment, multicentric Castleman disease can be life-threatening. Progressive organ dysfunction may occur as inflammatory proteins damage the kidneys, liver, lungs, and bone marrow. Severe anemia can develop, requiring blood transfusions, while low platelet counts increase bleeding risks.

The chronic inflammatory state may lead to secondary infections due to immune dysfunction, cardiovascular complications from persistent inflammation, and increased risk of developing other cancers, particularly lymphomas. In HHV-8-positive cases, patients may develop Kaposi sarcoma or primary effusion lymphoma.

Kidney dysfunction ranges from mild protein loss to complete kidney failure requiring dialysis. Neurological complications can include progressive weakness, cognitive impairment, and painful neuropathy that significantly impacts daily functioning.

Diagnosis

Diagnosing Castleman disease requires a combination of clinical evaluation, laboratory testing, imaging studies, and tissue biopsy. The diagnostic journey often involves multiple specialists and can take months to years due to the rarity and nonspecific symptoms.

Laboratory tests typically reveal elevated inflammatory markers including C-reactive protein and erythrocyte sedimentation rate, along with characteristic findings such as anemia, low albumin levels, and elevated interleukin-6. Additional blood work may show abnormal immunoglobulin levels and kidney function abnormalities.

Imaging studies including CT scans, MRI, and PET scans help identify enlarged lymph nodes and assess disease extent. These studies are crucial for distinguishing between unicentric and multicentric disease.

Lymph node biopsy remains the gold standard for diagnosis, revealing characteristic microscopic patterns including hyaline vascular, plasma cell, or mixed variants. Pathologists look for specific architectural changes and cellular patterns unique to Castleman disease.

HHV-8 testing through immunohistochemistry or PCR helps classify the disease subtype and guide treatment decisions. Additional testing may include HIV screening and assessment for other viral infections or autoimmune conditions.

Treatment

Treatment approaches vary significantly between unicentric and multicentric forms of Castleman disease. For unicentric disease, complete surgical removal of the affected lymph node often provides a cure, with excellent long-term outcomes.

Multicentric Castleman disease requires systemic therapy targeting the underlying inflammatory processes. Siltuximab, an anti-interleukin-6 monoclonal antibody, represents the first FDA-approved treatment specifically for this condition and has shown significant efficacy in clinical trials.

Rituximab, a monoclonal antibody targeting B-cells, is frequently used either alone or in combination with other therapies, particularly in HHV-8-positive cases. For patients with concurrent HIV, antiretroviral therapy forms an essential component of treatment.

Additional treatment options include corticosteroids for acute symptom management, chemotherapy regimens similar to those used in lymphomas, and supportive care measures such as blood transfusions, infection prevention, and nutritional support.

Emerging therapies under investigation include other cytokine inhibitors, immunomodulatory drugs, and targeted therapies aimed at specific molecular pathways involved in disease progression.

Prognosis

Prognosis varies dramatically between disease subtypes. Unicentric Castleman disease has an excellent outlook, with surgical removal typically providing complete cure and normal life expectancy. Long-term complications are rare following successful surgery.

Multicentric Castleman disease presents a more complex picture, with outcomes depending on disease subtype, patient immune status, and response to treatment. HHV-8-positive cases in HIV-infected patients historically had poor outcomes, but improved treatments have significantly enhanced survival rates.

With current therapies including siltuximab and rituximab, many patients achieve sustained remissions and maintain good quality of life. However, the disease can be progressive and life-limiting in some cases, particularly when complicated by organ dysfunction or secondary malignancies.

Early diagnosis and prompt treatment initiation significantly improve outcomes, emphasizing the importance of clinical awareness and rapid specialist referral when Castleman disease is suspected.

Quality of life

Living with Castleman disease requires ongoing medical management and lifestyle adaptations. Regular monitoring through blood tests and imaging helps track disease activity and treatment response. Patients often work closely with hematology-oncology teams and may require frequent clinic visits during active treatment phases.

Daily activities may be limited during disease flares due to fatigue, but many patients maintain good functional status between episodes or during treatment remissions. Energy conservation strategies and paced activities help manage fatigue effectively.

Diet and nutrition play important roles, with emphasis on maintaining adequate protein intake and hydration. Some patients may require nutritional supplements or dietary modifications based on kidney function or medication side effects.

Mental health support is crucial given the uncertainty and chronic nature of the condition. Counseling, support groups, and stress management techniques help patients cope with diagnosis-related anxiety and treatment challenges.

Work and education accommodations may be necessary during treatment periods, but many patients successfully continue their careers with appropriate workplace flexibility and medical leave when needed.

Pregnancy and fertility

Limited data exists regarding pregnancy outcomes in women with Castleman disease, requiring individualized management by maternal-fetal medicine specialists and hematologists. Active disease may complicate pregnancy through effects on blood counts, kidney function, and overall maternal health.

Treatment medications such as siltuximab and rituximab have limited safety data in pregnancy, necessitating careful risk-benefit discussions. Some treatments may need to be delayed or modified during pregnancy and breastfeeding.

Fertility preservation discussions should occur before starting treatment, particularly for younger patients requiring intensive therapies. Male fertility may be affected by certain treatments, making sperm banking an important consideration.

Genetic counseling is generally not required since Castleman disease is not inherited, though counseling regarding pregnancy risks and medication effects remains valuable.

Children

Castleman disease can occur in children and adolescents, though it remains rare in pediatric populations. Unicentric disease is more common in younger patients and often presents with localized lymph node masses that may be discovered incidentally or cause symptoms related to their location.

Pediatric diagnosis follows similar principles to adults but requires specialized pediatric pathology expertise. Treatment approaches may need modification for developing patients, with careful attention to growth and developmental impacts.

Long-term follow-up is particularly important in pediatric cases to monitor for late effects of treatment and ensure normal growth and development. Family education and age-appropriate patient education help manage the psychological impact of a rare disease diagnosis.

When to see a doctor

Seek immediate medical attention for persistent fevers, difficulty breathing, severe fatigue with pale skin, unusual bleeding or bruising, or rapidly enlarging lymph nodes. These symptoms may indicate serious complications requiring urgent evaluation.

Schedule routine medical evaluation for gradual onset of persistent fatigue, unexplained weight loss, night sweats lasting more than two weeks, or slowly enlarging lymph nodes that don’t resolve after several weeks.

Any combination of enlarged lymph nodes with systemic symptoms such as fever, weight loss, or fatigue warrants prompt medical assessment, as early diagnosis significantly impacts treatment outcomes.

Patients with known risk factors such as HIV infection should maintain regular medical follow-up and report new symptoms promptly to their healthcare providers.

Regional context

Limited epidemiological data exists specifically for Castleman disease prevalence in the Caucasus region (Georgia, Armenia, Azerbaijan) and broader Eastern Mediterranean area. The disease appears to occur worldwide with similar clinical characteristics, though regional variations in HHV-8 prevalence may influence disease patterns.

Healthcare infrastructure and access to specialized diagnostic capabilities may affect recognition and treatment of this rare condition in some areas. We invite healthcare professionals and researchers from these regions to contribute their clinical experiences and epidemiological observations to the Global Medical Journal to enhance our understanding of regional disease patterns.

Collaborative international research efforts remain crucial for advancing knowledge about this rare condition and improving outcomes for patients worldwide.

Research and clinical trials

Active research focuses on understanding disease mechanisms, developing targeted therapies, and improving diagnostic approaches. Current investigations examine the role of various cytokines beyond IL-6, genetic factors that may predispose to disease development, and optimal treatment combinations.

Promising areas include research into JAK inhibitors, other immunomodulatory agents, and precision medicine approaches based on molecular disease characteristics. Clinical trials are evaluating new monoclonal antibodies targeting different inflammatory pathways and combination therapies for refractory cases.

The Castleman Disease Collaborative Network maintains a patient registry and coordinates research efforts to accelerate discovery and improve treatments. Patients interested in clinical trial participation can search for opportunities at ClinicalTrials.gov or through specialized treatment centers.

International collaborations continue expanding our understanding of disease biology and treatment responses, with particular focus on rare subtypes and optimal management strategies for different patient populations.

Frequently asked questions

Is Castleman disease a type of cancer?

Castleman disease is classified as a rare cancer or lymphoproliferative disorder, but it behaves differently from typical cancers. Unlike most cancers, it results from immune system dysfunction rather than malignant transformation, though it can increase risk of developing other cancers.

Can Castleman disease be cured?

Unicentric Castleman disease can often be cured with complete surgical removal. Multicentric disease currently has no cure but can be effectively managed with treatments like siltuximab and rituximab, allowing many patients to achieve long-term remissions.

Is Castleman disease contagious?

Castleman disease itself is not contagious. However, some cases are associated with HHV-8 virus infection, which can be transmitted between people, though most HHV-8 infections do not lead to Castleman disease.

How is Castleman disease different from lymphoma?

While both affect lymph nodes, Castleman disease primarily involves excessive inflammation and immune dysfunction rather than malignant cell transformation seen in lymphomas. Treatment approaches and prognosis differ significantly between these conditions.

What should I expect during treatment?

Treatment typically involves regular infusions of targeted therapies like siltuximab, frequent monitoring through blood tests and imaging, and management of symptoms and side effects. Most patients can continue normal activities between treatments with appropriate support.

Support and resources

Castleman Disease Collaborative Network (CDCN)
Website: castlemannetwork.org
Comprehensive resource for patients, families, and healthcare providers with research updates, treatment information, and support services.

National Organization for Rare Disorders (NORD)
Website: rarediseases.org
General rare disease support, advocacy, and educational resources.

Orphanet
Website: orpha.net
European reference portal for rare diseases with detailed medical information.

EURORDIS Rare Diseases Europe
Website: eurordis.org
European alliance of rare disease patient organizations.

Leukemia & Lymphoma Society
Website: lls.org
Support services, educational materials, and financial assistance programs for blood cancer patients.

Related conditions

Lymphoma
Autoimmune lymphoproliferative syndrome
Kikuchi-Fujimoto disease
Rosai-Dorfman disease
Systemic lupus erythematosus

Sources: Orphanet (orpha.net), OMIM, GeneReviews (NCBI), WHO ICD-11, relevant guidelines. Informational only; not medical advice. CC BY 4.0.

Licensed under CC BY 4.0. Free to share with attribution to GMJ News.

Sources: Orphanet (orpha.net), OMIM, GeneReviews (NCBI), WHO ICD-11, EULAR/ACR guidelines. Schema.org MedicalCondition structured data included.