Castleman disease (CD) is a lymphoproliferative condition with a broad range of morphological and clinical presentations. It is categorized into distinct pathological and clinical subtypes, including localized unicentric CD, idiopathic multicentric CD, and human herpesvirus 8-associated or human herpesvirus 8-negative variants. Diagnosing CD requires adherence to internationally recognized guidelines that integrate clinical, laboratory, and histological findings. However, distinguishing CD from other diseases can be complex, as numerous benign and malignant conditions can mimic its features. Additionally, individuals diagnosed with CD are at an elevated risk of developing various malignancies. In this article, we reviewed benign and malignant conditions that can mimic CD.

Literature search is conducted and reviewed.

Mimickers of CD include follicular hyperplasia, indolent B-cell lymphoproliferative disorders, peripheral T-cell malignancies, classic Hodgkin lymphoma, follicular dendritic cell tumors, plasma cell disorders, immunoglobulin G4 -related lymphadenopathy, autoimmune-associated lymphadenopathy, infectious causes of lymphadenopathy, and systemic syndromes like POEMS and TAFRO. Various malignancies are associated with CD, including plasma cell proliferations, lymphomas, follicular dendritic cell neoplasms, and Kaposi sarcoma.

This review explores the differential diagnoses and neoplasms linked to CD, emphasizing their role in accurate classification, treatment decisions, and patient management. A comprehensive understanding of CD and its mimickers is crucial for ensuring accurate diagnosis and appropriate patient management in clinical practice.

Patients with acute liver failure (ALF) or acute-on-chronic liver failure (ACLF) are at high risk of bleeding with traditional artificial liver support systems. To address the bleeding risk in liver failure patients, the safety of regional mesylate anticoagulation (RMA) in centrifugation artificial liver support systems (cALSS) is proposed for study.

In this prospective single-arm study, ALF and ACLF patients were treated with cALSS using RMA. Coagulation function was monitored, and the predictors of mesylate dose were analyzed using the area under the curve (AUC). Blood ammonia, model for end-stage liver disease scores, and survival rates at 28 and 90 days were assessed.

All 57 patients showed no new bleeding within 24 h post-cALSS. Most disseminated intravascular coagulation indicators improved at 0.5 h and 24 h post-cALSS. Thromboelastography showed hypocoagulability at 0.5 h post-cALSS. Univariate and multivariate analyses identified pre-R and pre-MA as key factors for R exceeding 10 m at 0.5 h post-cALSS, with odds ratios of 0.91 (95% confidence interval (CI): 0.84–0.98) and 2.03 (95% CI: 1.05–3.90), respectively, P < 0.05. The predictive values were pre-MA ≤ 38 mm (AUC = 0.817, 95% CI [0.690–0.907], P < 0.001) and pre-R > 6.3 m (AUC = 0.790, 95% CI [0.661–0.888], P < 0.001). Patients showed improvements in blood ammonia and model for end-stage liver disease scores after the last session, especially those with high initial levels (>80 µmol/L and >30). The 28-day and 90-day survival rates of ALF patients were similar to those of ACLF patients.

cALSS with RMA is safe for liver failure patients with a high risk of bleeding. Adjusting the mesylate dose based on pre-R and pre-MA enhances safety.

Therapy-related B-lymphoblastic leukemia (B-ALL) following treatment for multiple myeloma is a rare occurrence. Despite its rarity and the lack of recognition by the World Health Organization as a distinct disease entity, previous publications indicate its possible emergence following myeloma treatment.

The patient is a 65-year-old gentleman with a history of IgG kappa multiple myeloma, status post multiple lines of therapy. The patient presented with a fever, and a complete blood count showed cytopenia. Bone marrow morphologic evaluation revealed numerous blasts. Immunophenotypic analysis demonstrated that these blasts were B lymphoblasts, despite MYC and unusual surface kappa light chain expression. A diagnosis of B-ALL with surface kappa light chain expression post-myeloma treatment was made. Ancillary studies indicated that the B-ALL and the previous myeloma were clonally unrelated. Next-generation gene sequencing revealed pathogenic mutations in KDM6A and KRAS.

This case highlights the potential for therapy-related B-ALL following myeloma treatment, a phenomenon deserving further investigation. The expression of surface light chain in blasts can present a diagnostic pitfall.

The International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytology was developed by a group of expert cytopathologists and clinicians in the breast field. Five categories are defined to stratify breast lesions by their risks of malignancy and managed accordingly. Clinical and radiologic information (triple test) are critical for further management. Ultrasound guidance, and rapid on-site evaluation are valuable for improving the rate of definitive diagnosis. Ancillary studies can be tested on cytologic samples to provide prognostic, predictive information as well as diagnostic clues. Based on many published studies in different institutions worldwide, the implementation of the system appears to have been successful. However, further studies are important for improvements and modifications to the current system.

The Paris System for Reporting Urinary Cytology (TPS 1.0, published in 2016) is the first standardized, evidence-based reporting system established as an international reporting system for urine specimens after the International Congress of Cytology in Paris. Its primary purpose is to reduce the rate of unnecessary indeterminate diagnoses but maintain the excellent performance of urine cytology, in detecting high-grade urothelial carcinoma. The reporting system comprises six diagnostic categories, as well as each category’s diagnostic criteria, estimated risk of malignancy, and management recommendations. After six years, TPS 2.0 was applied in 2022 upon the unfolding of new data. TPS 2.0 clarifies the diagnosis categories and updates the risk of malignancy in each category and developments of molecular tests. This review provides an updated summary of TPS 2.0. Some diagnostic pitfalls and molecular tests were also discussed.

The Bethesda System for Reporting Thyroid Cytopathology is the first reporting system established in non-gynecologic cytopathology after the Bethesda System for Reporting Cervical Cytopathology. It adopts the same concept of providing a uniform reporting system for all pathologists and clinicians to follow in thyroid cytology. The reporting system is composed of six diagnostic categories. There are defined diagnostic criteria, estimated risk of malignancy, and management recommendations for each category. The reporting system has undergone two revisions upon the emergence of a new entity, updated terminology in histology, and development and refinement of molecular testing. The third edition is soon to be published in 2023. This review will provide an updated summary of the reporting system. Potential diagnostic pitfalls and molecular testing are also discussed.