Severe refractory TAFRO syndrome requiring continuous renal replacement therapy complicated with Trichosporon asahii infection in the lungs and myocardial infarction: an autopsy case report and literature review

BACKGROUND: TAFRO (thrombocytopenia, anasarca, fever, reticulin myelofibrosis/renal failure, and organomegaly) syndrome is a systemic inflammatory disorder and unique clinicopathological variant of idiopathic multicentric Castleman disease that was proposed in Japan. Prompt diagnosis is critical because TAFRO syndrome is a progressive and life threating disease. Some cases are refractory to immunosuppressive treatments. Renal impairment is frequently observed in patients with TAFRO syndrome, and some severe cases require hemodialysis. Histological evaluation is important to understand the pathophysiology of TAFRO syndrome. However, systemic histopathological evaluation through autopsy in TAFRO syndrome has been rarely reported previously. CASE PRESENTATION: A 46-year-old Japanese man with chief complaints of fever and abdominal distension was diagnosed with TAFRO syndrome through imaging studies, laboratory findings, and pathological findings on cervical lymph node and bone marrow biopsies. Interleukin (IL)-6 and vascular endothelial growth factor (VEGF) levels were remarkably elevated in both blood and ascites. Methylprednisolone (mPSL) pulse therapy was initiated on day 10, followed by combination therapy with PSL and cyclosporine A. However, the amount of ascites did not respond to the treatment. The patient became anuric, and continuous renal replacement therapy was initiated from day 50. However, the patient suddenly experienced cardiac arrest associated with myocardial infarction (MI) on the same day. Although the emergent percutaneous coronary intervention was successfully performed, the patient died on day 52, despite intensive care. Autopsy was performed to ascertain the cause of MI and to identify the histopathological characteristics of TAFRO syndrome. CONCLUSIONS: Bacterial peritonitis, systemic cytomegalovirus infection, and Trichosporon asahii infection in the lungs were observed on autopsy. In addition, sepsis-related myocardial calcification was suspected. Management of infectious diseases is critical to reduce mortality in patients with TAFRO syndrome. Although the exact cause of MI could not be identified on autopsy, we considered embolization by fungal hyphae as a possible cause. Endothelial injury possibly caused by excessive secretion of IL-6 and VEGF contributed to renal impairment. Fibrotic changes in anterior mediastinal fat tissue could be a characteristic pathological finding in patients with TAFRO syndrome.