Unicentric Castleman disease presenting as hyperenhancing mediastinal mass: A case series diagnosed by linear endobronchial ultrasound guided mediastinal nodal biopsy.

Unicentric Castleman disease (UCD) is an uncommon benign lymphoproliferative disorder that typically presents as solitary mediastinal or hilar nodal enlargement and may mimic malignant or hyper vascular lesions on imaging. We describe a case series of three women presenting with solitary, well-circumscribed mediastinal or hilar masses-two presented with chronic dry cough (one associated with anaemia) and one identified incidentally during routine screening. Contrast-enhanced computed tomography (CECT) demonstrated intensely enhancing hyper vascular nodal lesions, while positron emission tomography-computed tomography (PET-CT) revealed mild fluorodeoxyglucose uptake without additional nodal or extra nodal involvement, supporting an unicentric process. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed that was nondiagnostic in all cases, yielding reactive cytology without architectural detail. In contrast, EBUS-guided intranodal forceps or cryo biopsy was performed that resulted adequate tissue with preserved nodal architecture, helping definitive histopathological and immunohistochemical diagnosis of hyaline vascular UCD. Two patients subsequently underwent complete surgical excision followed by symptomatic resolution and favourable outcomes, while one declined surgery. This series highlights the characteristic clinic-radiologic pattern of solitary hyper enhancing thoracic nodal disease and underscores the limitations of needle aspiration cytology. Minimally invasive mediastinal nodal biopsy can establish definitive diagnosis preoperatively and facilitate timely curative management in patients with UCD.