February 2026 Research Update

Across studies of unicentric Castleman disease (UCD), complete surgical removal was repeatedly linked with good outcomes, especially when the disease is in one spot and can be fully taken out. A small retroperitoneal UCD series reported no recurrences over long follow-up, and a larger review of published extranodal UCD cases also found surgery was the most common approach with generally strong recurrence-free outcomes. This month adds reassurance that when UCD is localized and fully resected, many people do well for years, while also keeping in view that recurrence or transformation can still happen in a minority of reported cases. [1] [2]

In 11 people with retroperitoneal UCD treated in routine care, surgeons achieved complete removal in every case, with no severe postoperative complications reported and no recurrences or deaths during an average follow-up of about 68 months. The report included both laparoscopic and open surgery, suggesting more than one surgical approach can be used depending on the situation. For patients, the main message is that long-term disease control after complete resection was observed in this small group. [1]

Looking across 99 published cases of primary extranodal UCD, surgery was used in most patients and the review reported a high recurrence-free survival at 4 years, although follow-up in the published literature was often short. The same review also described a small risk of transformation to B-cell lymphoma in a few cases, showing why outcomes can vary even within UCD. Taken together with the surgical series, this reinforces that UCD is often managed as a local problem, but not every reported case follows an identical course. [2]

For people with UCD, this month strengthens the overall picture that complete surgical removal is commonly followed by long periods without the disease coming back, including in hard-to-reach places like the retroperitoneum. The evidence here comes from retrospective reports and published cases, so it cannot guarantee what will happen for an individual, and follow-up length varies widely across reports. What became clearer is the consistency of the pattern: when UCD is truly localized and fully removed, many patients in these reports remained well, while a small minority of published cases had recurrence or later lymphoma. This mostly adds to understanding of expected outcomes rather than changing anything immediately. [1] [2]

This month included early signals about treatments for multicentric Castleman disease (MCD) and its subtypes, but the evidence is still limited and comes from a very small trial and several single-patient reports. Filgotinib (a JAK1 inhibitor) was generally tolerated over 52 weeks in 5 people with idiopathic MCD (iMCD), with some patients showing improved disease activity scores and lab markers. Case reports highlighted that treatment response can depend on the specific type of MCD, with different approaches used for iMCD-TAFRO, HHV-8-associated MCD, and severe lung involvement. [3] [4] [5] [6]

In a 52-week extension study in 5 people with iMCD, filgotinib 200 mg daily had no serious adverse events or deaths reported, and side effects were described as mild-to-moderate. By week 52, 3 of 5 patients had at least a 1-point reduction in a disease activity score (CHAP), alongside improvements in markers like C-reactive protein, hemoglobin, and albumin. This adds longer-term safety and "signal of benefit" information, but it does not show how filgotinib compares with other treatments because there was no comparison group. [3]

A case report of iMCD with TAFRO syndrome occurring alongside Sjogren's syndrome described sustained remission after high-dose corticosteroids followed by tocilizumab (an IL-6 blocker), with recovery in blood counts, kidney function, inflammation markers, and imaging findings. Another iMCD-TAFRO case described a rare skin presentation that progressed to severe clotting-related skin injury in the setting of small-vessel damage, with gradual healing over 6 weeks after MCD-directed therapy plus wound care. Together, these cases underline how iMCD-TAFRO can present in complex ways and how anti-inflammatory and immune-targeting treatments are sometimes used, but single cases cannot predict what will happen for others. [4] [7]

In one HHV-8-associated MCD case in an HIV-negative man, tocilizumab did not control symptoms before the correct diagnosis was made, while rituximab plus liposomal doxorubicin was followed by rapid improvement in systemic inflammation, clearing of HHV-8 in the blood, and neurological recovery. Another case described severe breathing failure linked to bronchiolitis obliterans in MCD that did not respond adequately to steroids, where bilateral lung transplantation was followed by major breathing improvement and survival without supplemental oxygen at 4 years. These reports expand the range of real-world situations seen in MCD and show that treatment pathways can differ widely depending on the driver of disease and which organs are affected. [5] [6]

For patients and caregivers, this month adds context that MCD is not one single condition, and treatments discussed in the literature can look very different depending on whether the disease is idiopathic (including TAFRO) or linked to HHV-8, and on which organs are involved. The filgotinib results may matter in the future if confirmed in larger studies, because they provide 1 year of safety information in a small group and show that some patients had measurable improvement. The case reports mainly add understanding of rare presentations and individualized treatment choices, including situations where one medicine did not work and another approach did. What remains uncertain is how often these results apply to others, because most evidence here is early-stage and based on very small numbers. [3] [4] [7] [5] [6]

This month reinforced that imaging can suggest Castleman disease, but the final diagnosis usually depends on looking at tissue under the microscope, and a few reports highlighted uncommon complications. In TAFRO syndrome, PET/CT scans commonly showed multiple enlarged lymph nodes with increased uptake, sometimes alongside fluid around the lungs or belly, which may help capture the full-body pattern of disease. In localized (unicentric) cases, masses in the mesentery or pancreas were initially suspected to be other tumors, and confirmation came only after surgical removal and pathology. [8] [9] [10]

In a small series of 5 people with TAFRO syndrome who had PET/CT, all had enlarged lymph nodes with higher-than-usual uptake (SUVmax greater than 2.5), and some had splenomegaly, signs of active bone marrow, and visible pleural effusions or ascites. The authors argued that whole-body PET/CT may help with assessment because it can show both lymph nodes and organ involvement in one test. For patients, the practical meaning is that imaging may help map where disease activity appears to be and support assessment. Other reports this month showed that tissue examination was needed to confirm the diagnosis when imaging could not separate Castleman disease from other masses. [8] [9]

Several UCD reports illustrated how Castleman disease can imitate other conditions on scans. One mesenteric mass looked like a gastrointestinal stromal tumor (GIST) on imaging, but pathology after excision confirmed hyaline vascular UCD and there was no recurrence at 18 months. These reports emphasize why tissue confirmation matters when imaging is not specific. [9]

Rare but meaningful complications were also described in localized disease. One pancreatic-region UCD case included a pseudoaneurysm that formed and ruptured within the tumor, followed by surgery and no recurrence at 24 months. Another report described two mesenteric Castleman disease cases where one had a favorable course after resection, while the other progressed and later showed transformation into a peripheral T-cell lymphoma within 5 months. [10] [11]

For patients, this group of studies clarifies two things: first, Castleman disease can be difficult to identify from imaging alone, so confirmation from a biopsy or surgical specimen remains central in reported cases. Second, even when disease is localized, unusual events can occur, such as bleeding from fragile blood vessels within a mass or, rarely, later lymphoma in published reports. The PET/CT findings in TAFRO syndrome may matter now as part of how some centers assess disease extent, but the study is small and does not prove that PET/CT changes outcomes. The complication and transformation reports are mainly reminders from individual cases, not predictions of what will happen to most people. [8] [9] [10] [11]

This month also included a case report showing that unicentric Castleman disease (UCD) can sometimes come with body-wide immune symptoms that improve after the localized mass is removed. The reported example involved paraneoplastic pemphigus, a painful blistering condition affecting skin and mucous membranes. While this is rare, it adds to the picture that a single localized lymph node mass can sometimes trigger symptoms far beyond the mass itself. [12]

In the reported case, a 28-year-old woman with hyaline vascular UCD had paraneoplastic pemphigus and underwent complete surgical resection of a retroperitoneal mass. Over time, her mouth and hand erosions healed, and at 2 years she had no recurrence on CT and no return of the mucocutaneous lesions. This supports the idea that, in at least some people, removing the UCD lesion can be followed by improvement of immune-driven symptoms. [12]

For patients, this report may be most relevant if someone has UCD along with unexplained blistering or erosive skin and mouth problems, because it documents one way these conditions can appear together. It does not show how common this is, and it cannot tell whether surgery will resolve symptoms in others, but it helps confirm that UCD can sometimes be linked to symptoms outside the lymph node area. This is mainly descriptive evidence that adds understanding rather than changing standard expectations. [12]