Paraneoplastic pemphigus presenting as a prodrome to aggressive T cell lymphoma.

Paraneoplastic pemphigus (PNP) is a rare disease with an unclear mechanism of pathogenesis. We present a case of a male patient who presented with wound management after being diagnosed with Castleman disease-associated paraneoplastic pemphigus (PNP). The patient's condition was not improving; as a result, extensive workup was repeated, which confirmed the diagnosis of aggressive T cell lymphoblastic lymphoma. Our case signifies the importance of keeping a high index of suspicion for PNP-associated malignancies. This case report also adds emphasis to the diagnostic challenges faced by clinicians, making clinical correlation with multidisciplinary approach essential. Therefore, if clinically indicated, we need to revisit the diagnosis and seek alternative explanations to prevent delays in management.

Kaposi sarcoma-associated herpesvirus complement control protein (KCP) and glycoprotein K8.1 are not required for viral infection in vitro or in vivo.

Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, is the causal agent of Kaposi sarcoma, a cancer that appears as tumors on the skin or mucosal surfaces, as well as primary effusion lymphoma and KSHV-associated multicentric Castleman disease, which are B-cell lymphoproliferative disorders. Effective prophylactic and therapeutic strategies against KSHV infection and its associated diseases are needed. To develop these strategies, it is crucial to identify and target viral glycoproteins involved in KSHV infection of host cells. Multiple KSHV glycoproteins expressed on the viral envelope are thought to play a pivotal role in viral infection, but the infection mechanisms involving these glycoproteins remain largely unknown. We investigated the role of two KSHV envelope glycoproteins, KSHV complement control protein (KCP) and K8.1, in viral infection in various cell types in vitro and in vivo. Using our newly generated anti-KCP antibodies, previously characterized anti-K8.1 antibodies, and recombinant mutant KSHV viruses lacking KCP, K8.1, or both, we demonstrated the presence of KCP and K8.1 on the surface of both virions and KSHV-infected cells. We showed that KSHV lacking KCP and/or K8.1 remained infectious in KSHV-susceptible cell lines, including epithelial, endothelial, and fibroblast, when compared to wild-type recombinant KSHV. We also provide the first evidence that KSHV lacking K8.1 or both KCP and K8.1 can infect human B cells in vivo in a humanized mouse model. Thus, these results suggest that neither KCP nor K8.1 is required for KSHV infection of various host cell types and that these glycoproteins do not determine KSHV cell tropism. IMPORTANCE: Kaposi sarcoma-associated herpesvirus (KSHV) is an oncogenic human gamma-herpesvirus associated with the endothelial malignancy Kaposi sarcoma and the lymphoproliferative disorders primary effusion lymphoma and multicentric Castleman disease. Determining how KSHV glycoproteins such as complement control protein (KCP) and K8.1 contribute to the establishment, persistence, and transmission of viral infection will be key for developing effective anti-viral vaccines and therapies to prevent and treat KSHV infection and KSHV-associated diseases. Using newly generated anti-KCP antibodies, previously characterized anti-K8.1 antibodies, and recombinant mutant KSHV viruses lacking KCP and/or K8.1, we show that KCP and K8.1 can be found on the surface of both virions and KSHV-infected cells. Furthermore, we show that KSHV lacking KCP and/or K8.1 remains infectious to diverse cell types susceptible to KSHV in vitro and to human B cells in vivo in a humanized mouse model, thus providing evidence that these viral glycoproteins are not required for KSHV infection.

A unicentric center, multicenter, and mixed-type Castleman disease: Three case reports and a review of the literature.

RATIONALE: Due to the lack of specificity symptoms and site of onset of castleman disease (CD), it is difficult to diagnose and poses unique challenges for both patients and clinicians, leading to confusion in diagnosis and delays in treatment. To enhance understanding, we present 3 cases of CD treated at our hospital, including a single-center, multicenter, and mixed-type CD. PATIENT CONCERNS: Case 1: A 53-year-old female patient was admitted with a chief complaint of "abdominal pain and fever for 10 days." Marked enlargement of inguinal lymph nodes on both sides was observed. Case 2: A 58-year-old female patient was admitted with the main complaint of "discovering a left lower abdominal mass during a routine checkup for the past 10 days." Upon deep palpation, a palpable mass of approximately 5.0 * 3.0 cm was identified in the left lower abdomen. Case 3: A 40-year-old male patient was admitted with the main complaint of "progressive right upper abdominal and lumbar back pain for over 6 months." Computed tomography examination revealed multiple nodular soft tissue masses between the abdominal aorta and inferior vena cava, with the largest measuring 5.0 * 4.0 cm. DIAGNOSES: Based on the immunohistochemical results, the diagnoses for the 3 patients are as follows: Case 1: Multicentric Castleman's Disease (Mixed Type). Case 2: Pelvic Retroperitoneal Castleman Disease (Hyaline Vascular Type). Case 3: Castleman Disease Multicentric Type. INTERVENTION: Case 1: cyclophosphamide 0.6-1 g + vincristine 2 mg + methylprednisolone 50 mg/5 days. Cyclophosphamide 1 g + prednisone 30-50 mg/5 days. This alternating chemotherapy cycle is repeated every 6 months. Case 2: Laparoscopic pelvic mass excision surgery. Case 3: Surgical excision of the mass. OUTCOMES: Case 1: After a 43-month follow-up, the patient's general symptoms have improved compared to before, but regular chemotherapy is still necessary at present. Case 2: The patient did not take any medication postoperatively, and there has been no evidence of metastasis or recurrence during the 18-month follow-up. Case 3: The patient did not take any medication, and there has been no evidence of metastasis or recurrence during the 21-month follow-up. LESSONS SUBSECTIONS: The lack of specific signs on imaging studies and nonspecific blood tests increases the difficulty of diagnosis. However, tissue biopsy remains a feasible option. Therefore, we recommend conducting thorough examinations for suspected CD patients to reduce misdiagnosis and determine the CD type for effective targeted treatment.

Molecular Features of HHV8 Monoclonal Microlymphoma Associated with Kaposi Sarcoma and Multicentric Castleman Disease in an HIV-Negative Patient.

Human herpesvirus 8 (HHV8)-associated diseases include Kaposi sarcoma (KS), multicentric Castleman disease (MCD), germinotropic lymphoproliferative disorder (GLPD), Kaposi sarcoma inflammatory cytokine syndrome (KICS), HHV8-positive diffuse large B-cell lymphoma (HHV8+ DLBCL), primary effusion lymphoma (PEL), and extra-cavitary PEL (ECPEL). We report the case of a human immunodeficiency virus (HIV)-negative male treated for cutaneous KS, who developed generalized lymphadenopathy, hepatosplenomegaly, pleural and abdominal effusions, renal insufficiency, and pancytopenia. The excised lymph node showed features of concomitant involvement by micro-KS and MCD, with aggregates of HHV8+, Epstein Barr virus (EBV)-negative, IgM+, and lambda+ plasmablasts reminiscent of microlymphoma. Molecular investigations revealed a somatically hypermutated (SHM) monoclonal rearrangement of the immunoglobulin heavy chain (IGH), accounting for 4% of the B-cell population of the lymph node. Mutational analyses identified a pathogenic variant of KMT2D and variants of unknown significance in KMT2D, FOXO1, ARID1A, and KMT2A. The patient died shortly after surgery. The histological features (HHV8+, EBV-, IgM+, Lambda+, MCD+), integrated with the molecular findings (monoclonal IGH, SHM+, KMT2D mutated), supported the diagnosis of a monoclonal HHV8+ microlymphoma, with features intermediate between an incipient HHV8+ DLBCL and an EBV-negative ECPEL highlighting the challenges in the accurate classification of HHV8-driven lymphoid proliferations.

Preoperative Direct Puncture Embolization of Castleman Disease of the Parotid Gland: A Case Report.

BACKGROUND: Castleman disease (CD) is an uncommon benign lymphoproliferative disease characterized by hypervascular lymphoid hyperplasia. We present a unique case of unicentric CD of the parotid gland treated by preoperative direct puncture embolization. CASE PRESENTATION: A 27-year-old female patient was admitted for a right neck mass. Ultrasound examination and MRI scan documented a hypervascular mass within the right parotid gland. Preoperative embolization was performed by direct puncture technique: a needle was inserted into the core of the mass under both ultrasound and fluoroscopic guidance and SQUID 12 was injected into the mass under fluoroscopic control, achieving a total devascularization. CONCLUSION: Preoperative direct puncture embolization was safe and effective and provides excellent hemostatic control during the surgical operation, limiting the amount of intraoperative bleeding.

Castleman Disease Presenting in the Neck: A Report of 3 Cases and a Literature Review.

BACKGROUND Castleman's disease (CD) is a reactive lymph node hyperplasia initially identified by Castleman in 1956. CD predominantly affects individuals 20-50 years of age, with low incidence in children. This case report describes 3 cases of CD treated in our hospital and reviews the relevant literature. The purpose of this case report was to enhance clinical understanding and treatment of CD in the head and neck in children. CASE REPORT To enhance clinical understanding and improve treatment of CD in the head and neck region in children, we present the cases of 3 patients who were admitted to the hospital, primarily presenting with a neck mass. Preoperatively, the patients collectively exhibited non-specific findings. Surgical interventions were performed with Cases 1 and 3 undergoing left functional (radical) neck lymph node dissection, in contrast to Case 2, in which bilateral functional (radical) neck lymph node dissection was executed. Pathological examination confirmed the diagnosis of CD in each of the 3 patients. Following surgery, a follow-up period ranging from 3 months to 1 year revealed that all patients had successfully recovered, with no recurrence. CONCLUSIONS Castleman disease is a rare disease in children and difficult clinical diagnosis. Some patients with unicentric Castleman disease (UCD) can be treated with surgery, and those with multicentric Castleman disease (MCD) need chemotherapy, but at present there is no widely accepted treatment plan.

[Improvement of tissue fibrosis in TAFRO syndrome by prednisolone monotherapy].

We report the case of a 48-year-old man who presented with fatigue and weight loss. A local physician observed elevated alkaline phosphatase levels, anemia, thrombocytopenia, and renal dysfunction. Fever also appeared, and the patient was admitted to our hospital. Computed tomography revealed hepatosplenomegaly, pleural and ascitic fluid, and left axillary lymphadenopathy. Bone marrow biopsy indicated hyperplasia with increased megakaryocytes and reticulin fibrosis. Axillary lymph node biopsy showed Castleman's disease-like features. Liver biopsy revealed proliferation of reticulin fibrosis. Therefore, TAFRO syndrome was diagnosed and treatment with 1 mg/kg prednisolone was started. Anemia and thrombocytopenia improved, and after 24 weeks of treatment, serum hyaluronic acid and type IV collagen decreased to the normal range. Bone marrow biopsy after 18 weeks of treatment showed decreased reticular fibers. In TAFRO syndrome, improvement of liver and bone marrow fibrosis can be expected with adequate intervention, and serum hyaluronic acid and type IV collagen are useful for evaluating fibrosis.

Unicentric Castleman's disease in the parotid gland associated with psoriasis: a case report.

BACKGROUND: Castleman's disease is a rare lymphoproliferative disorder that is often misdiagnosed because of its untypical clinical or imaging features except for a painless mass. Besides, it is also difficult to cure Castleman's disease due to its unclear pathogenesis. CASE PRESENTATION: We present a Castleman's disease case with diagnostic significance regarding a 54-year-old Chinese male who has a painless mass in his left parotid gland for 18 months with a 30-years history of autoimmune disease psoriasis. Computed tomography scan showed a high-density nodule with clear boundaries in the left parotid and multiple enlarged lymph nodes in the left submandibular and neck region. General checkup, the extremely elevated serum interleukin-6 and lymph node biopsy in the left submandibular region gave us an initial suspicion of Castleman's disease. Then the patient underwent a left superficial parotidectomy. Based on histopathologic analysis, we made a certain diagnosis of Castleman's disease and gave corresponding treatments. In 18 months of follow-up, the patient showed no evidence of recurrence, with the level of serum interleukin-6 decreased. CONCLUSIONS: Clinicians should be aware of the possibility of Castleman's disease when faced with masses or enlarged lymph nodes in the parotid gland to avoid misdiagnosis, especially in patients with autoimmune diseases and elevated serum interleukin-6.

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.

Acquired Hemophilia: A Rare Complication of Pediatric Idiopathic Multicentric Castleman Disease.

Acquired hemophilia is caused by acquired autoantibodies to 1 of the factors of the coagulation cascade, usually factor VIII or IX, and is an exceedingly rare phenomenon in children. The finding of an acquired factor VIII inhibitor in a pediatric patient with idiopathic multicentric Castleman disease has never been reported. Patients with acquired hemophilia can have life-threatening bleeds that are refractory to blood product support, requiring bypassing agents to manage bleeding symptoms. We present the novel finding of acquired hemophilia resulting from an autoantibody to factor VIII in a pediatric patient with idiopathic multicentric Castleman disease and discuss the optimal management of bleeding in a patient with acquired hemophilia.

Enfermedad de Castleman, fisiopatología, avances en el diagnóstico y tratamiento / Castleman's disease, pathophysiology, advances in diagnosis and treatment

La enfermedad de Castleman (EC) engloba a un conjunto heterogéneo de procesos linfoproliferativos que comparten rasgos histológicos bien definidos. Se considera una enfermedad rara o minoritaria u su incidencia no es del todo conocida, aunque se estima en menos de uno por cada 100.000 habitantes. Tiene una distribución bimodal (30-40 años y luego los 60-80 años). Su incidencia es similar en ambos sexos, aunque la variante unicéntrica parece tener ligero predominio en mujeres con proporción 2:1. La EC se clasifica en una forma hialinovascular (siendo esta la más frecuente) y otra plasmocelular, relacionadas con el virus de la inmunodeficiencia humana (VIH) y el virus herpes humano tipo 8 (VHH-8), que junto a otros mecanismos autoinmunitarios desarrollan la hiperproducción de interleucina-6 (IL-6) por parte de los linfocitos B. Existen diferentes líneas de tratamiento, donde destaca el uso de anti IL-6, siendo el siltuximab el más utilizado y catalogado como el fármaco huérfano de esta patología.(AU)

Castleman's disease (CD) encompasses a heterogeneous set of reactive lymphoproliferative processes that share well-defined histologic features. CD is considered a rare or minority disease. The incidence of CD is not fully known, although it is estimated at less than 1 per 100,000 inhabitants. It has a bimodal distribution (30–40 years and then 60–80 years). The incidence is similar in both sexes, although the unicentric variant seems to have a slight predominance in women with a 2:1 ratio. CD is classified into a hyalinovascular form (this being the most frequent) and a plasmocellular form, related to the HIV and VHH-8 viruses, which together with other autoimmune mechanisms develop hyperproduction of interleukin-6 (IL-6) by B lymphocytes. There are different lines of treatment, where the use of anti IL-6 stands out, being siltuximab the most used as orphan drug in this pathology.(AU)

A prospective study of zanubrutinib, a Bruton tyrosine kinase inhibitor, in relapsed/refractory idiopathic multicentric Castleman disease.

Relapsed and refractory (R/R) idiopathic multicentric Castleman disease (iMCD) is a clinical challenge with no standard treatment. In this preliminary clinical trial, we investigated the efficacy and safety profiles of a Bruton tyrosine kinase inhibitor (BTKi), zanubrutinib, in patients with R/R iMCD. The primary endpoint was the overall response rate at Week 12 according to the Castleman Disease Collaborative Network (CDCN) response criteria. The trial was terminated early due to a lack of treatment response in the first enrolled 5 patients. Although 3 patients achieved symptomatic response, none of the 5 patients had an overall response by Week 12. One patient had progressive disease and the other 4 had stable disease. The study drug was well tolerated without grade 2 or higher adverse events. Our findings suggest that BTKi therapy is not effective for iMCD, and further attempts at single-agent therapy with zanubrutinib or other BTKis for iMCD should be considered with caution and probably avoided. This trial was registered at www.clinialtrials.gov as #NCT04743687.

TAFRO syndrome is associated with anti-SSA/Ro60 antibodies, in contrast to idiopathic castleman disease.

TAFRO syndrome is an acute systemic inflammatory disease characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, and organomegaly. There have been increasing reports that TAFRO is a disease distinct from idiopathic multicentric Castleman disease and that TAFRO patients may be positive for anti-SSA antibodies. To assess anti-SSA antibody positivity and the clinical characteristics of the two diseases, we retrospectively compared 7 TAFRO and 10 iMCD patients in our hospital. The mean age of onset of TAFRO and iMCD was 48.0 (interquartile range [IQR], 41-53) and 45.0 (IQR, 35-53) years, respectively. The TAFRO and iMCD groups had 6 (86%) and 4 (40%) male patients, respectively, and the following pretreatment laboratory values: platelet count, 3.8 (IQR, 2.2-6.4) and 35.5 (IQR, 22.2-42.8) × 104/µL, respectively; C-reactive protein, 10.2 (IQR, 6.8-21.4) and 9.5 (IQR, 6.2-13.6) mg/dL, respectively; IgG, 1431 (IQR, 1112-1815) and 4725 (IQR, 3755-5121) mg/dL, respectively. RNA immunoprecipitation (5 cases for anti-SSA) or protein array (5 cases for anti-SSA/Ro60) detected anti-SSA antibodies in six (86%) TAFRO patients but not in iMCD patients; it did not detect anti-SSB antibodies in any of the patients. None of the patients were diagnosed with Sjögren syndrome. All iMCD patients treated with tocilizumab (TCZ) responded well. Meanwhile, two of six TAFRO patients treated with TCZ showed inadequate responses; thus, both patients were switched to rituximab, following which they achieved remission. TAFRO and iMCD have different clinical features. TAFRO may be categorized as a severe phenotype of the anti-SSA antibody syndrome.