Authors: Thanh Thuy Phan, Minh Hung Dong, Thu Phuong Phan, Van Giap Vu
Categories: Case Report
Source: Respiratory Medicine Case Reports
Castleman disease (CD) is a rare lymphoproliferative disorder, most often presenting as a solitary hypervascular mediastinal mass and classified clinically into unicentric (UCD) and multicentric (MCD) forms, with histopathologic subtypes including hyalinized vascular, plasma cell, mixed and HHV-8-associated variants. Surgical resection remains both diagnostic and therapeutic, but significant intraoperative hemorrhage is a known risk given the tumor's vascularity. We report the case of a 55-year-old woman with a 52 × 28 mm hypervascular mass encircling the trachea—primarily below the carina and abutting the right esophageal border. Angiography revealed extensive tumor vascularization with early venous drainage. To minimize intraoperative bleeding, preoperative embolization was performed using a histoacryl–lipiodol mixture (1:3 ratio), achieving complete occlusion of the two feeding arteries on post-embolization angiography. Two weeks later, the posterior mediastinal lesion was resected with less than 50 mL of blood loss and complete excision. The patient recovered uneventfully, confirming that targeted preoperative embolization can safely facilitate resection of hypervascular mediastinal Castleman lesions.
Castleman disease is a rare form of lymph node hyperplasia, first described by Benjamin Castleman in 1954. The disease has diverse clinical manifestations, nonspecific histopathological features, can be found in other diseases, causing many difficulties in diagnosis, especially preoperative diagnosis [1]. According to clinical manifestations, the disease can be divided into unicentric (localized or unifocal) and multicentric (generalized or multifocal) [2]. Unicentric Castleman disease (UCD) presents as a solitary, painless, non-malignant, and slow-growing mass localized to a single anatomical site. Initially asymptomatic, it may begin to cause symptoms as it enlarges and compresses surrounding structures [3,4]. In contrast, multicentric Castleman disease (MCD) occurs at multiple sites and is characterized by an inflammatory response that triggers so-called B symptoms, including fever, night sweats, and weight loss. Elevated serum IL-6 levels contribute to a range of clinical manifestations, such as lymphadenopathy, hepatosplenomegaly, and polyclonal hypergammaglobulinemia [2].
Pathologically, Castleman disease can be classified into the hyalinized vascular type (HV-CD), plasma cell type, mixed type, and human herpesvirus-8 (HHV-8)-associated Castleman disease [1]. The exact cause of Castleman disease remains unclear and requires further research. However, existing data suggest that the condition results from immune dysregulation, leading to excessive proliferation of B lymphocytes and plasma cells within lymphoid organs.
Unicentric CD most commonly involves the mediastinum, accounting for approximately 85 % hyalinized vascular and 15 % plasma cell subtypes, and is frequently discovered incidentally in asymptomatic or minimally symptomatic patients. Surgical resection remains the gold standard for both diagnosis and treatment, but marked tumor hypervascularity can lead to significant intraoperative hemorrhage, limiting the safety of excision. Although CT-guided core needle biopsy can yield histopathologic confirmation, its limited diagnostic accuracy and bleeding risk often favor direct surgical excision. Preoperative embolization of tumor-feeding vessels has been shown to reduce intraoperative blood loss, as demonstrated in reports using Trisacryl gelatin microspheres.
In lesions characterized by pronounced neovascularization, preoperative embolization provides a distinct intraoperative hemostatic advantage. In their 2009 report, Swee W. et al. employed Trisacryl gelatin microspheres to embolize two mediastinal Castleman lesions, achieving a marked reduction in blood loss and thereby affirming embolization's role as an effective preoperative adjunct [2]. In this report, we present a case emphasizing targeted preoperative embolization as a strategic intervention to facilitate safe resection of a hypervascular mediastinal Castleman lesion.
A 55-year-old woman presented with a one-month history of intermittent, stabbing right-sided chest pain that intensified with exertion. Her past medical history was notable for uterine fibroid surgery and a documented penicillin allergy ten months prior. The pain was non-radiating and occurred without cough, fever, weight loss, or other systemic symptoms. She also reported one week of difficulty swallowing. Despite evaluations at multiple facilities, no definitive diagnosis was reached, and her symptoms persisted. She was therefore admitted to the Respiratory Center at Bach Mai Hospital for further workup.
On examination, she was alert and hemodynamically stable, with a blood pressure of 120/70 mmHg and a heart rate of 78 bpm. There was no peripheral edema or palpable lymphadenopathy, and no evidence of mediastinal syndrome. Cardiac auscultation revealed a regular rhythm; lung fields were clear without rales.
Contrast-enhanced chest CT (64– to 128-slice) demonstrated a well-circumscribed, hypervascular mass measuring 52 × 28 mm encircling the trachea, predominantly below the carina and abutting the right esophageal border. The lesion contained focal calcifications and exhibited intense contrast enhancement. Both the right and left bronchial arteries arose from a common trunk; while their proximal segments appeared normal, the distal right bronchial artery was markedly dilated and tortuous (3.9 mm in diameter), and the distal left bronchial artery was mildly enlarged (2.1 mm). These features were consistent with a highly vascular mediastinal mass and showed no imaging characteristics suggestive of lymphoma (Fig. 1, Fig. 2). Abdominal CT revealed no evidence of lymphadenopathy.
Fig. 1 Hypervascular posterior mediastinal tumor before (red arrow) and after embolization (white arrow).
Fig. 2 3D Reconstruction of the hypervascular posterior mediastinal tumor (white arrow).
Subsequent bronchoscopy revealed normal bronchial mucosa but prominent vascular proliferation bilaterally (Fig. 3). Microbiological analyses—including bronchial fluid cultures, acid‐fast bacilli smear, fungal microscopy, and Mycobacterium tuberculosis PCR—were all negative.
Fig. 3 Proliferation of bronchial vasculature on both main bronchi (white arrow).
Following multidisciplinary review, preoperative arterial embolization was performed. Baseline coagulation tests were within normal limits (PT 108.5 %, INR 0.95, APTT 0.85) and platelet count was 248 G/L; blood chemistries were unremarkable (urea 4.9 mmol/L, creatinine 55 μmol/L, AST 14 U/L, ALT 17 U/L). Under local anesthesia, the right common femoral artery was accessed with a 5F sheath. Aortography revealed two tumor feeders arising from the thoracic aorta, which were selectively catheterized via microcatheter. Angiography confirmed dense neovascularization with early venous drainage. Embolization using a 3 histoacryl–lipiodol mixture achieved complete occlusion of both feeders on post-embolization imaging. The procedure was uneventful, the patient remained hemodynamically stable throughout, and hemostasis at the access site was achieved by manual compression.
Two weeks later, the patient underwent combined open and thoracoscopic resection in the left lateral decubitus position. A 4-cm posterior axillary thoracotomy was made in the fifth intercostal space, with a 10 mm trocar placed in the seventh intercostal space for thoracoscopic visualization. Intraoperatively, a well-demarcated 3 × 5 × 6 cm hypervascular mass was identified at the tracheobronchial bifurcation. The right posterior mediastinal pleura was opened and multiple feeding vessels were divided using Ligasure electrosurgical dissection. The tumor was carefully dissected from the esophagus, carina, and main bronchi, with meticulous hemostasis throughout. The specimen was sent for histopathology, two absorbable hemostatic agents were applied, and a single pleural drain was placed (Fig. 4). Total intraoperative blood loss was approximately 50 mL. The postoperative course was uneventful, and the patient recovered fully by one week without complications.
Fig. 4 Resected tumor following surgical excision.
Gross Examination: The excised specimen measured 6.3 × 4.5 × 2.5 cm and exhibited a soft, gray cut surface. The capsule was partially disrupted, and focal areas demonstrated increased firmness.
Histopathological Findings: Microscopy revealed numerous lymphoid follicles with atrophic germinal centers—some containing hyalinized blood vessels. The mantle zones were expanded, displaying concentric rings of lymphocytes. Central regions of coagulative necrosis contained residual embolic material within vascular lumina.
Histopathological Diagnosis: These features are diagnostic of hyalinized vascular‐type Castleman disease (Fig. 5).
Fig. 5 Characteristic histopathological features of Castleman disease, demonstrating the “onion skin-like” pattern of concentric lymphocytic arrangement in the mantle zone and the “lollipop” appearance of hyalinized blood vessels penetrating atrophic germinal centers. (white arrow) (H&E, 10x).
Follow-up and Outcome: At one-month follow-up, the patient remained asymptomatic, reporting no chest pain or dysphagia. Physical examination was unremarkable, and repeat contrast-enhanced chest CT demonstrated stable postoperative changes with no residual or recurrent mediastinal mass.
Castleman disease is a rare condition with limited treatment options. In cases of unicentric Castleman disease (UCD), complete surgical excision of the localized lesion remains the treatment of choice. For multicentric Castleman disease (MCD), multiple therapeutic approaches are available, including surgery, chemotherapy with or without corticosteroids, and autologous stem cell transplantation, with varying degrees of success. Chemotherapeutic agents and immunomodulatory therapies are typically reserved for recurrent or refractory cases [1].
Our case involved a unicentric Castleman disease (UCD) presenting as an isolated mediastinal lymph node. However, the tumor was located in a challenging anatomical position and exhibited significant vascular proliferation. Conventional biopsy techniques, such as transthoracic needle biopsy or endoscopic ultrasound-guided lymph node biopsy, were deemed high-risk due to technical difficulties and the potential for severe complications. As a result, the chosen strategy was preoperative embolization to minimize intraoperative complications. This approach successfully reduced vascularity, allowing for tumor resection with minimal blood loss (<50 mL) and complete excision of the lesion. A study by Ko SF et al. (2003), which analyzed eight cases of Castleman disease surgery, reported an average intraoperative blood loss of 620 mL, further supporting the efficacy of preoperative embolization in reducing surgical hemorrhage [5]. Preoperative embolization in Castleman disease has also been reported by Swee W et al., demonstrating its effectiveness in reducing surgical blood loss. Their case report documented a minimal intraoperative blood loss of only 50 mL, with no postoperative complications. This further supports the role of embolization as a valuable adjunct in the surgical management of highly vascularized Castleman disease lesions [2].
Some patients, unfortunately, present with tumors that compress adjacent structures, adhere to major blood vessels, or involve critical organs, making surgical resection challenging or even unfeasibl [6]. In such cases, radiotherapy may be considered as an adjunctive therapy in an attempt to shrink the tumor before surgical excision. Garcia S. and Fan J. (2021) reported a case of a 25-year-old male with a large 8.2 cm mediastinal mass located below the carina, demonstrating internal calcifications and causing compression and narrowing of the right main pulmonary artery and left main bronchus [7]. Despite attempts at endobronchial ultrasound-guided biopsy and cervical mediastinoscopy, cytological analysis was inconclusive for diagnosis. Due to vascular involvement and adhesion to vital structures, surgical excision was not feasible. The patient underwent chemotherapy with rituximab, followed by cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), combined with radiotherapy, but showed minimal response [7].
Castleman disease can often be misdiagnosed as lymphoma or other tumors. Accurate diagnosis and differentiation from other diseases require a comprehensive clinical history, imaging studies, and histopathological examination. In cases of highly vascularized tumors, establishing an optimal management strategy is crucial for both diagnosis and minimizing surgical complications.
Preoperative arterial embolization represents a safe and highly effective adjunct to surgical resection of hypervascular mediastinal unicentric Castleman disease. By dramatically reducing intraoperative blood loss and facilitating clear tumor margins, this targeted strategy optimizes surgical safety and enables complete excision with minimal complications. In vascular UCD cases, a multidisciplinary approach that incorporates selective embolization should be considered best practice to improve operative outcomes and patient recovery.
Thanh Thuy Phan: Writing – review & editing, Writing – original draft, Visualization, Methodology, Formal analysis, Data curation, Conceptualization. Minh Hung Dong: Writing – original draft, Methodology, Data curation. Thu Phuong Phan: Writing – review & editing, Supervision. Van Giap Vu: Writing – review & editing, Supervision, Methodology.
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Handling Editor: DR AC Amit Chopra