Histomorphologic spectrum in hyaline vascular variant of castleman disease

Introduction: Castleman Disease (CD) is a rare lymphoproliferative disorder with heterogenous clinical and pathological features. It is a rare disease with mention in the rare disease data of the orphanet. It can present as unicentric or multicentric disease. Hyaline vascular variant and plasma cell variant are the two pathological subtypes. Hyaline vascular variant accounts for nearly 80% to 90% of unicentric cases. Hyaline vascular subtype variant has follicular and stroma rich subtype. Aim: To study the histomorphologic spectrum of hyaline vascular variant of CD. Materials and Methods: Retrospective cross-sectional, observational study was undertaken from the archival data between January 2009 and April 2015. Only ten cases of hyaline vascular CD were identified after studying the histomorphological characteristics. Both follicular and interfollicular changes were studied in detail. Results: The age of presentation ranged from 17 years to 59 years. Seven out of 10 cases were female. Site of presentation included cervical, inguinal, retroperitoneal, intra-abdominal and axillary. Six cases showed predominant follicular change. Two cases were sclerotic subtype. Two cases showed both follicular and interfollicular changes in equal proportion. Distribution of follicles throughout the lymphnode was seen in eight cases. Uniform sized follicles seen in seven out of ten cases. Small germinal centre with lymphocyte depletion was one of the uniform features seen in all 10 cases. Numerous high endothelial vessels were seen in nine cases. Twinning of germinal centre was seen in two cases. All ten cases showed concentric rings of small lymphocytes. Lollipop pattern was relatively rare feature seen in only two cases. Conclusion: Hyaline vascular variant of CD has considerable morphologic variation with few consistent features seen in most of the cases.