Fatal breakthrough mucormycosis in a multivisceral transplant patient receiving micafungin: Case report and literature review

Abstract

Introduction: Antifungal agents are routinely used in the post-transplant setting for both prophylaxis and treatment of presumed and proven fungal infections. Micafungin is an echinocandin-class antifungal with broad antifungal cover and favorable side effect profile but, notably, it has no activity against molds of the order Mucorales.

Presentation of case: A 47-year-old woman underwent multivisceral transplantation for intestinal failure-associated liver disease. She had a prolonged post-operative recovery complicated by invasive candidiasis and developed an intolerance to liposomal amphotericin B. In view of her immunosuppression, she was commenced on micafungin as prophylaxis to prevent invasive fungal infection. However, she developed acute graft versus host disease with bone marrow failure complicated by disseminated mucormycosis which was only diagnosed post mortem.

Discussion: Non-Aspergillus breakthrough mold infections with micafungin therapy are rare with only eight other cases having been described in the literature. Breakthrough infections have occurred within one week of starting micafungin. Diagnosis is problematic and requires a high degree of clinical suspicion and microscopic/histological examination of an involved site. The management of these aggressive infections involves extensive debridement and appropriate antifungal cover.

Conclusion: A high level of suspicion of invasive fungal infection is required at all times in immunosuppressed patients, even those receiving antifungal prophylaxis. Early biopsy is required. Even with early recognition and aggressive treatment of these infections, prognosis is poor.

Keywords: Antifungal therapy; CMV, cytomegalovirus; CT, computed tomography scan; Fungal infection; GvHD, graft-versus-host disease; Immunosuppression; L-AmB, liposomal amphotericin B; MIC, minimum inhibitory concentration; Micafungin; Mucormycosis; Multivisceral transplantation; bd, twice daily; od, once daily; spp., species.

Fig. 1

A. CT abdomen at day 165 showing poor enhancement of the liver with heterogeneous attenuation of the right lobe, gas in the left renal vein (long arrow) and infarcts in the right kidney (short arrow). B. CT head at day 165 showing extensive bilateral cerebral infarction (long arrows), left fronto-parietal hemorrhage (short arrow) and mass effect within the left cerebral hemisphere.