SpyGlass DS -Directed Radiofrequency Ablation with Double Biliary Metal Stent Placement for Managing Recurrent Obstructive Jaundice Secondary to Castleman Disease: A Case Report of a Rare Disease (with Videos)

Castleman disease (CD) rarely presents with obstructive jaundice, which poses a diagnostic and therapeutic challenge to the management of the disease. A 40-year-old man was referred to our hospital for emergent management of upper abdominal pain. An abdominal mass was removed, and the postoperative pathology showed retroperitoneum CD, which was subsequently managed by adjuvant therapy of combination chemotherapy and steroids. One month later, a biliary metal stent was placed due to the presentation of obstructive jaundice. After approximately 3 months, the patient experienced another episode of obstructive jaundice, and SpyGlass DS cholangioscopy (Boston Scientific, Natick, Mass, USA) was performed via the biliary track for biopsy, which pathologically showed biliary malignancies. Radiofrequency ablation was performed with a probe (EMcision, Montreal, Canada), and another uncovered metal stent was placed within the existing metal stent. No stent occlusion occurred during a 6-month follow-up period. In conclusion, CD rarely presents with obstructive jaundice, and a combination of radiofrequency ablation with metal stent implantation under cholangioscopy can prolong the stent patency time and the survival time of patients.


Introduction
Castleman disease (CD) is a rare lymphoproliferative disorder that was first described by Benjamin Castleman [1] . Clinically, CD can be divided into unicentric and multicentric subtypes, which lead to different prognoses [2] . Radical surgical resection with adjuvant chemoradiotherapy is the treatment of choice. In cases of multiple metastasis, palliative care may be the only option.
CD rarely presents with obstructive jaundice. At present, only 12 relevant case reports can be found in the literature, and most of the patients in these reports received radical operations [3] . Radiofrequency ablation (RFA) has been proven to be a safe and effective method for the treatment of biliary malignancies [4] . In 2015, the novel digital single-operator cholangioscopy system (SpyGlass DS) was introduced and provides high-resolution images for visualization of the biliary tract and biopsy biliary stricture for establishing a definitive diagnosis [5] . Here, we report the first case of multicentric CD that involved the biliary tract and presented with obstructive jaundice, which was further treated by RFA and metal stent placement under SpyGlass DS cholangioscopy, and finally achieved complete and durable remission.

Case report
The study was approved by the institutional research ethics committee of the First Hospital of Jilin University, the project identification code 19K041-001, June 2019. and written informed consent was obtained from each subject. A 40-year-old man presented to our hospital with yellow skin, sclera, and dark urine lasting for 5 days.

Discussion
CD is a rare disease entity in which the causes of reactive lymphadenopathy are unknown. Pathologically, CD features obvious proliferation of lymphoid follicles, blood vessels as well as plasma cells to varying degrees [2] , and further can be divided into hyaline-vascular type and plasma cell type. Clinically, it is characterized by significant enlargement of deep or superficial lymph nodes and, in some patients, systemic symptoms and/or multiple system damage.
The disease is classified as unicentric CD (UCD) or multicentric CD (MCD) subtypes. UCD is more common in young people; pathologically, 90% of UCD cases are the hyaline-vascular type, and surgical resection of enlarged lymph nodes offers a good prognosis. In comparison, MCD is less common than UCD, and patients with MCD always present with enlargement of multiple lymph nodes in combination with systemic symptoms. In some cases, these symptoms include only fever or liver splenomegaly. However, in 20%-30% of patients, MCD manifests as nephrotic syndrome, amyloidosis, myasthenia gravis, Kaposi's sarcoma, or B-cell lymphoma.

MCD is usually invasive and associated with infection, and the prognosis is poor
when it is associated with malignant transformation or lymphoma [6] .
To date, 13 cases of CD with jaundice, including the present case, have been reported in the English literature [3] , including 7 MCD and 6 UCD cases. Histopathologically, 7 cases were diagnosed as hyaline vascular type, 3 cases as plasma cell type, and 3 cases as the mixed type. In all UCD cases, resection was success, and symptoms disappeared completely during follow-up. In contrast, cases of MCD were partially controlled or relapsed.
The involvement of the biliary tract poses diagnostic and therapeutic challenges in the management of CD. A systematic review of nine studies with 505 patients [7] found that RFA combined with biliary stent placement offered a pooled mean difference of Digital single-operator cholangioscopy (SpyGlass DS) with direct visualization and biopsy for diagnosis of biliary tract diseases has been shown to be safe and to offer a high success rate [8] . RFA for malignant biliary stricture using SpyGlass DS not only retains the safety but also increases the success rate of the treatment. In addition, SpyBite can easily execute biopsies under SpyGlass DS, leading to improved diagnostic accuracy [9][10][11] .
In summary, we report the first case of multicentric CD presenting with jaundice due to biliary tract re-occlusion, which was treated by SpyGlass DS-directed RFA and double metal stent insertion, subsequently leading to complete and durable remission of the disease.

Conclusions
CD rarely presents as jaundice due to obstruction of the biliary track. However, such cases can be feasibly and effectively managed by SpyGlass DS-directed RFA with metal stent insertion, which may improve stent patency time and survival time.