Talaromyces marneffei: A challenging diagnosis in a kidney transplant patient

Key Clinical Message In addition to post‐transplant lymphoproliferative disorders, it is necessary to be alert to the drug‐resistant bacteria or fungal infection, especially Talaromyces marneffei, in kidney transplant patients who have failed antibiotic treatment and whose PET‐CT indicates high metabolic mass in the transplanted kidney with a large number of other organs and lymph nodes. Abstract Talaromyces marneffei (TM) is a rare pathogenic fungus that primarily affects individuals with compromised immune systems. Post‐transplant lymphoproliferative disorders (PTLD) are serious complications that can occur after solid organ and cell transplantation. Both TM infection and PTLD can invade the monocyte–macrophage system and often manifest as extranodal masses. This case report describes a kidney transplant patient who presented with symptoms of frequent, urgent, and painful urination over 6 months. Pulmonary CT scans revealed multiple nodules, and PET‐CT demonstrated enlarged lymph nodes in the lungs and the transplanted kidney. The clinical manifestations closely mimicked those of PTLD. The confirmation of TM was achieved through pathogen metagenomic next‐generation sequencing and renal biopsy. Unfortunately, despite receiving treatment with antifungal agents, anti‐infective therapy, the patient's condition did not respond favorably, ultimately resulting in their unfortunate demise due to COVID‐19.