The application of a multidisciplinary approach in the diagnosis of Castleman disease and Castleman-like lymphadenopathies: A 20-year retrospective analysis of clinical and pathological features

Castleman disease-type histopathological patterns of lymph nodes in patients with plasma cell neoplasia and POEMS syndrome

Plasma cell neoplasia and POEMS syndrome patients may present Castleman disease (CD)-type features in lymph nodes. Our aim was to better characterize the histopathological patterns found in plasma cell neoplasia associated CD and to improve the detection of clonal plasma cell populations in the lymph node biopsies of these patients. Lymph node and bone marrow samples from six cases with plasma cell neoplasia associated CD, including POEMS syndrome and multiple myeloma were analyzed. A complete analysis including morphology, IHC and PCR-based clonality detection in the lymph node biopsies and morphology; IHC and FCM in the bone marrow biopsies was done. Correlation with clinical and laboratory features was performed. Both plasma cell rich and hyper vascular Castleman disease like histopathological features were found. In two out of six cases, sheets of plasma cells with light chain and isotype restriction were identified in the lymph nodes. B cell clonality analysis provided evidence of clonal populations in 5 out of 6 cases, increasing the sensitivity for the detection in cases without morphologically identifiable monotypic plasma cells. None of the twelve control cases with iMCD and HHV-8 positive CD showed clonal populations. In conclusion, the combination of morphology, complete immunophenotyping and B cell clonality analysis in the lymph node biopsy may provide evidence of clonal populations in up to 83 % of cases with plasma cell neoplasia/POEMS syndrome associated Castleman disease. Clinical work-up for the confirmation of plasma cell dyscrasia is advisable in such cases.

Axillary Reactive Lymphoid Hyperplasia, Likely Due to Unicentric Castleman Disease, and the Concurrent Presence of Orbital Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma: A Six-Year Follow-Up Study

Castleman disease is a lymphadenopathy of unknown cause at a single site, which is designated as unicentric Castleman disease, or at multiple sites designated as multicentric Castleman disease. We present a patient who showed axillary reactive lymphoid hyperplasia, likely due to unicentric Castleman disease, and orbital extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma in a six-year follow-up. A 76-year-old man had a painless left axillary mass for an unknown period and also left complete blepharoptosis with no other systemic symptoms. Suspected of lymphoma, iliac bone marrow biopsy showed no anomalous cells, and positron emission tomography demonstrated abnormal uptake at the left axilla and in the left superior anterior orbit. Incisional biopsy of the left axillary mass demonstrated hyperplastic lymphoid follicles with an atrophic germinal center and prominent small vessels in the follicular center, indicative of unicentric Castleman disease. One year later, annual follow-up positron emission tomography disclosed a high uptake site, next to the previously-identified cyst, in the pancreatic body. Trans-gastric fine needle pancreatic biopsy proved adenocarcinoma and he underwent subtotal stomach-preserving pancreaticoduodenectomy with jejunal anastomosis. He was well for six months after the surgery and thus, underwent resection of the left orbital lesion at 78 years old. The pathology of the orbital lesion showed ambiguous nodular structure with massive infiltration with CD20-positive medium-sized lymphoid cells which were κ monotype in immunoglobulin light chain restriction, indicative of MALT lymphoma. In the four-year period of the COVID-19 pandemic, he was healthy and followed with no treatment until the age of 82 years when he underwent radiation (46 Gy) to the left axillary lesion which did not regress. He then underwent eyelid levator muscle plication for left blepharoptosis since the left orbital lesion remained unpalpable. The six-year follow-up showed that concurrent and independent orbital MALT lymphoma and axillary reactive lymphoid hyperplasia, likely due to unicentric Castleman disease, were both stable. The present case illustrates how important it is to make pathological diagnoses in different anatomical lesions after the initial diagnosis of Castleman disease.

Overview of Research Status in Castleman Disease

Castleman disease (CD) is characterized by the proliferation of lymphoid tissue and encompasses a range of disorders that vary in clinical presentation, histopathological features, and therapeutic approaches. This article presents a comprehensive review of the current state of CD research, emphasizing the etiology, pathogenesis, clinical manifestations, diagnostic criteria, treatment options, and prognostic factors. CD is a relatively rare condition infrequently encountered in clinical practice. Certain subtypes of CD progress rapidly and pose a significant threat to patient health. Consequently, a timely and accurate diagnosis is crucial. This article aimed to equip clinicians and researchers with an updated and detailed understanding of CD, thereby enhancing the management of this complex condition.