An Unusual Case of Disseminated Erdheim-Chester Disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytic multisystem disorder, deriving from mononuclear phagocytic cells. It is notoriously challenging to diagnose. Here we present a case of a patient with multisystem ECD.

A 76-year-old female with a history of Hashimoto's thyroiditis who presented with persistent leukocytosis was found to have bilateral renal enlargement with a perinephric mass, a recurrent pericardial effusion, and bilateral pleural effusions. Following biopsies of several sites of involvement, a diagnosis of ECD was made.

The existing literature on ECD is sparse, and no diagnostic criteria have been put forward due to widely differing presentations, although the most common is skeletal. Definitive diagnosis requires a tissue sample.

In presenting our clinical reasoning and approach, we hope to contribute to the existing body of literature on ECD, with the aim of ultimately having sufficient data to compile a diagnostic framework for other clinicians who encounter ECD.