Disseminated nocardiosis masking an atypical zygomycosis presentation in a kidney transplant recipient

Abstract

Immunosuppressive agents increase the vulnerability of solid organ transplant patients to opportunistic infections. An atypical clinical presentation of a bacterial and fungal co-infection makes diagnosis and treatment even more challenging in this population. A 54-year-old hypertensive woman underwent a cadaveric kidney transplant after years on hemodialysis. Her treatment included mycophenolate, tacrolimus, and prednisone. By post-transplant week 8, she had pneumonia followed by progressive visual changes and seizures. Diagnostic work-up, consisting of magnetic resonance imaging of the brain and chest x-ray, showed several cerebral ring-enhancing lesions, and a pulmonary cavitary lesion. Disseminated nocardiosis was suspected and therapy was started. Skin biopsy was taken from a nodular lesion and culture confirmed Nocardia species infection. During hospitalization, neurological deficit persisted with worsening of brain lesions. She underwent excision of a brain abscess and the final pathologic report showed mucormycosis, revealing the patient's co-infection by 2 different pathogens. After therapy with liposomal amphotericin B and posaconazole, she has remained stable for more than 1 year. Disseminated nocardiosis masked and delayed the diagnosis and treatment of a more aggressive and worrisome organism. Mucormycosis, as a non-fatal isolated brain abscess without rhinal involvement, is an atypical presentation, and only a few cases have been reported.