Human Herpesvirus 8-Positive Multicentric Castleman Disease in an Immunocompetent Patient: A Diagnostic Challenge

We present a clinical case of a 79-year-old male admitted to inpatient care for longstanding asthenia and respiratory symptoms. Associated features were polyserositis, multiple enlarged lymphatic nodules, acute kidney injury, and heart failure. The patient's recent medical history revealed SARS-CoV-2 vaccination a week prior and an upper respiratory tract infection. The laboratory results from thoracentesis were compatible with a transudate, with no immunological stain. Epstein-Barr virus polymerase chain reaction (PCR) was positive. The thoracic, abdominal, and pelvic CT scans revealed multiple enlarged lymphatic nodules, worsening the pre-existent polyserositis and hepatosplenomegaly. The patient began to show signs of neurologic symptoms and deterioration of the global health status. An enlarged lymphatic nodule was excised and the pathology showed human herpesvirus 8 multicentric Castleman disease. The disease evolved rapidly into hematological dysfunction and blood transfusions were necessary. Even though the patient was started on high-dose rituximab therapy combined with etoposide, the disease evolved into multiorgan dysfunction with a fatal outcome.