Clinicopathological comparison and therapeutic approach to Castleman disease-a case-based review.

Castleman disease (CD) is a rare, B-cell lymphoproliferative disorder affecting lymph nodes and extranodal anatomical locations. Four types of clinical presentations can be distinguished after exclusion of mimics. The first division is into unicentric CD (UCD) and multicentric CD (MCD). MCD is classified further as HHV-8-negative (idiopathic), MCD associated with HHV-8 infection, and POEMS associated MCD. From the histological standpoint, UCD and MCD can be classified as hyaline-vascular (HV), plasma cell (PC), or mixed cellularity (MC) type, with a spectrum of histopathological manifestations. We present clinical and histopathological features and grading of 25 cases of CD classified according to CDCN histological criteria and according to this clinical algorithm, along with outcomes. Here we provide a fine-resolution description of the histological features of CD. We review and discuss the current diagnostic algorithm, grading system, and recently recommended treatment options. In the presented group of 25 patients with CD there were 14 women and 11 men in the age range 15-79 years. UCD was identified in 15 patients and it was most often located in mediastinum. MCD most frequently occurred as generalized lymphadenopathy. The most common type of CD was HV. All patients with UCD underwent complete surgical resection with a positive outcome. Patients with MCD had diagnostic partial surgical excision of the lesions, later followed by different types of treatment (corticosteroids, chemotherapy, radiotherapy, immunomodulatory agents) or 'watch and wait'. In four cases CD was associated with other malignancies (laryngeal cancer, small lymphocytic lymphoma, gallbladder cancer with hepatic metastases, primary squamous cell lung cancer). The accuracy of histopathological examination is essential and re-evaluation has to be performed in case of relapse or unexpected course of CD. Treatment tailored to fit the disease type and severity should follow the novel recommendations, including anti-IL-6 treatment in the case of MCD. 2019 Journal of Thoracic Disease. All rights reserved.