An Elusive Diagnosis of Castleman’s Disease

We present the case of a 41-year-old male with an anterior mediastinal mass and constellation of clinical symptoms, including dyspnea, pleural effusions, pericardial effusions, renal insufficiency, and pancytopenia. After several inconclusive laboratory tests and non-diagnostic surgical biopsy, a second surgical biopsy identified the patient’s condition as Castleman’s disease associated with TAFRO (thrombocytopenia, anasarca, fevers, reticulin myelofibrosis, organomegaly) syndrome. This case highlights the importance of obtaining large tissue biopsies, interval follow-up, and acknowledging cognitive biases.