July 2026 Research Update

This month added a clearer picture of how different Castleman disease situations are being treated in day-to-day care, with results that depend heavily on the subtype and how widespread the disease is. In small series, unicentric Castleman disease (one main area) did well when it could be fully removed, and a single unresectable case improved after radiotherapy. In multicentric Castleman disease (multiple areas) and closely related syndromes like TAFRO, drug combinations were used, with some reports showing remission and others showing difficult-to-control illness. [1] [2] [3] [4]

In a 12-patient hospital series, all unicentric cases had no recurrence after complete surgical removal during follow-up, while multicentric cases were treated with chemotherapy-based regimens and were reported to do well during the observed period. The same report described one multicentric patient who relapsed on rituximab but later reached complete remission after switching to an oral regimen, with IL-6 blood levels declining after that change. This helps connect the idea that multicentric disease often needs ongoing systemic therapy, but the best sequence of therapies was not tested in a controlled way in this study. [1]

In children, a small single-center case series reported complete remission in all four patients over 6 to 30 months, most often after surgery for unicentric disease and after rituximab plus combination chemotherapy for one severe idiopathic multicentric case. Because the group was small and treatments differed across patients, it mainly shows what was feasible at one center rather than proving one best approach. Still, it adds reassurance that complete remission was achievable in these pediatric cases with individualized care. [3]

One teenage patient with unresectable unicentric mediastinal disease had about 50% tumor shrinkage and improved breathing function after radiotherapy, with no significant reported toxicity over 13 months. This single case strengthens the idea that radiotherapy can be a non-surgical option when surgery is not possible, but it does not tell how often this works or how durable it is long term. [2]

For patients, these studies mainly add practical context about what treatment courses can look like for different forms of Castleman disease. The strongest and most consistent story in these reports is that unicentric disease can sometimes be controlled with local treatment (especially complete removal, and in one case radiotherapy when removal was not feasible). For multicentric disease and related inflammatory syndromes, these reports show that combinations of immune-targeting drugs and chemotherapy are used, and the course can range from remission to refractory illness with serious complications in individual cases. [1] [2] [3] [4]

Because most of this evidence comes from small retrospective series and individual cases, it is best viewed as an early map of possibilities rather than a definitive answer about which treatment is best. What remains uncertain is how to choose between different systemic regimens for multicentric disease, and how to predict who will have a smoother course versus a more severe one. Even with that uncertainty, these reports help clarify that the subtype and disease extent strongly shape treatment plans and expected monitoring needs. [1] [3] [2]

This month's case reports showed that Castleman disease can be part of a broader, complicated picture rather than a single straightforward diagnosis. Several cases emphasized that reaching the diagnosis depended on tissue biopsy plus imaging, especially when symptoms came from the lungs, fluid around the lung, nerve problems, or overlapping syndromes like Kaposi sarcoma or POEMS-like features. Across these reports, lab markers (like HHV-8 viral load or specific autoantibodies) sometimes changed along with the patient's course, suggesting a potential way to follow disease activity in certain situations. [5] [6] [7] [8] [9]

In HHV-8-associated multicentric Castleman disease, one person with advanced HIV achieved complete clinical and imaging remission after rituximab-based therapy with etoposide, and HHV-8 viral load became undetectable after treatment. Another HIV-negative person with HHV-8-associated multicentric disease had Kaposi sarcoma and POEMS-like features and showed a clinical and blood response after three cycles of daratumumab, bortezomib, cyclophosphamide, and dexamethasone. Together, these cases underline that HHV-8 status can be central to the story, and that treatment approaches can vary widely depending on the full clinical situation. [5] [9]

In idiopathic multicentric Castleman disease, one case presented mainly as pleural thickening with a large pleural effusion, and symptoms and fluid improved after corticosteroids and tocilizumab. In contrast, a separate report of TAFRO syndrome described an individual who did not achieve durable control despite glucocorticoids, tocilizumab, and rituximab, and the course included severe kidney failure and multiple infections. These two reports side-by-side show how inflammatory Castleman-related conditions can behave very differently from one patient to another. [8] [4]

Two reports focused on overlapping syndromes where Castleman disease is part of a wider immune or plasma cell problem. One person with POEMS syndrome and mixed-type Castleman disease had imaging clues (including nerve-root changes and mixed bone lesions) that supported earlier recognition, followed by lenalidomide and dexamethasone with gradual partial neurologic recovery. Another person with unicentric Castleman disease had paraneoplastic pemphigus with skin and mouth lesions that improved after tumor removal, while a serious small-airway lung condition progressed despite treatment. [7] [6]

For patients and caregivers, these cases mainly help set expectations about variability: Castleman disease can sometimes look like lung symptoms, fluid buildup, nerve problems, or overlapping conditions rather than just enlarged lymph nodes. They also show that getting the right diagnosis often relied on a biopsy plus imaging, and in some situations specific markers like HHV-8 viral load or certain antibodies changed as the illness improved or worsened. This information may matter now for understanding what doctors may look for, but it does not prove that any single test or treatment will work for most people. [5] [6] [7] [8] [9]

What remains uncertain is how often these unusual presentations occur and which monitoring markers best predict relapses or responses across different Castleman subtypes. Because each report is a single person, the main value is helping patients recognize that a wide range of symptom patterns have been reported, including both recovery and severe complications depending on the situation. [4] [6] [5]

This month included a single case that focused on imaging rather than treatment. The report documented what Castleman disease looked like on two different PET/CT scans in the same person with multiple neck lymph nodes involved. It adds an example of how imaging choices may differ in research settings, but it does not establish which scan is better or how imaging should guide care. [10]

Specifically, the case described imaging findings using 18F-FDG PET/CT and 68Ga-pentixafor PET/CT. Because the summary does not report a direct performance comparison or patient outcomes tied to the scans, the main contribution is descriptive: it shows that both tracers were used and what they showed in that one patient. [10]

For patients, this report is mainly early research context about how Castleman disease can be imaged. It may matter later if larger studies show that one scan helps track disease or guides decisions better, but this single case does not answer those questions. For now, it mainly helps explain why different PET/CT scans might be mentioned in some Castleman disease evaluations. [10]