How I diagnose Castleman disease.

Abstract

Castleman disease represents a heterogeneous group of hematologic conditions with a broad spectrum of histopathologic features. Historically, 2 major Castleman disease subgroups have been described-unicentric Castleman disease and multicentric Castleman disease, based on the extent of the disease. More recently, oligocentric Castleman disease, a subtype that falls between unicentric and multicentric, has been identified. Due to the overlapping features of each category, similarities to other conditions, and a lack of objective diagnostic biomarkers, the diagnosis of Castleman disease remains a challenge. Here, we review the diagnostic criteria of each entity and discuss the features that distinguish them from overlapping diseases. This review highlights the clinicopathologic features of multiple cases to depict the wide spectrum of clinical and laboratory characteristics of Castleman disease. It also outlines the diagnostic workup for each subtype. In Castleman disease, the morphologic findings are nonspecific and represent a histologic pattern rather than a pathognomonic feature that allows definitive separation from other morphologically overlapping entities; therefore, correlation with clinical history, radiologic studies, and laboratory findings is essential to arrive at the correct diagnosis. Castleman disease represents a spectrum of clinical syndromes with overlapping morphological features.