# Unraveling the Complexities of Idiopathic Multicentric Castleman Disease and Its Multi-systemic Associations: A Case Report

## TL;DR

This case report explores a rare disease called idiopathic multicentric Castleman disease in a young woman, highlighting its complex connections with antiphospholipid syndrome and a virus.

## Contribution

The report provides new insights into the potential link between HHV-6 and Castleman disease, and the importance of early APS detection.

## Key findings

- A patient with idiopathic multicentric Castleman disease also had antiphospholipid syndrome and HHV-6 positivity.
- Treatment with siltuximab and tocilizumab was effective, suggesting IL-6's role in the disease.
- The case highlights the plasma cell variant of Castleman disease and its multi-systemic associations.

## Abstract

Castleman disease (CD) comprises a rare spectrum of disorders characterized by benign lymphoepithelial proliferation, classified into unicentric and multicentric forms. The idiopathic multicentric Castleman disease (iMCD) subtype, specifically, is challenging to diagnose and treat due to its variable manifestations and unpredictable disease course. We report a case of a 23-year-old female with a history of iron deficiency anemia presenting with concurrent antiphospholipid syndrome (APS) and human herpesvirus-6 (HHV-6) positivity. Investigations revealed a gastric mass, with a biopsy suggestive of the plasma cell variant of CD. This case report aims to understand the possible association of HHV-6 positivity with CD and the significance of diagnosing APS early in patients with the disease. Treatment with siltuximab and tocilizumab proved effective, highlighting the role of interleukin 6 (IL-6) in the elusive etiology of this condition.