Intra-abdominal Rhizopus microsporus infection successfully treated by combined aggressive surgical, antifungal, and iron chelating therapy

A Cecal Mucormycosis Mass Mimicking Colon Cancer in a Patient with Renal Transplant: A Case Report and Literature Review

Patient: Male, 64-year-old

Final Diagnosis: Cecal mucormycosis

Symptoms: Abdominal pain • diarhea • nausea • vomiting

Medication: —

Clinical Procedure: Ileostomy placement • right hemicolectomy

Specialty: Surgery

Transfusion related iron overload in pediatric oncology patients treated at a tertiary care centre and treatment with chelation therapy

We conducted a retrospective chart review to determine prevalence of, risk factors for, and liver toxicity associated with Transfusion Related Iron Overload (TRIO) in pediatric cancer patients, and report our experience with Iron Chelation Therapy (ICT). Total number of transfusions was identified as the major risk factor, with a prevalence of 37% in patients receiving ≥10 transfusions. Four patients with TRIO and abnormal liver function tests (LFT) received ICT. Significant decrease in serum ferritin and improvement in LFT were observed, with no serious adverse effects from ICT noted. Guidelines for screening and treatment of TRIO in pediatric oncology are needed.

Clinical challenge: fatal mucormycotic osteomyelitis caused by Rhizopus microsporus despite aggressive multimodal treatment

BACKGROUND

Mucormycosis is an invasive mycotic disease caused by fungi in the zygomycetes class. Although ubiquitous in the environment, zygomycetes are rarely known to cause invasive disease in immunocompromised hosts with a high mortality even under aggressive antifungal and surgical therapy. Clinically, mucormycosis frequently affects the sinus occasionally showing pulmonary or cerebral involvement. However skeletal manifestation with Rhizopus microsporus (RM) osteomyelitis leading to emergency surgical proximal femoral resection with fatal outcome has not been described yet.

CASE PRESENTATION

We report the case of a 73-year-old male suffering from myelodysplastic syndrome with precedent bone marrow transplantation. Six months after transplantation he consulted our internal medicine department in a septic condition with a four week history of painful swelling of the right hip. Radiography, computed tomography and magnetic resonance imaging revealed multiple bone infarcts in both femurs. In the right femoral head, neck and trochanteric region a recent infarct showed massive secondary osteomyelitis, breaking through the medial cortex. Emergency surgical proximal femoral resection was performed due to extensive bone and soft tissue destruction. Microbiological and basic local alignment search tool (BLAST) analysis revealed RM. Amphotericin B and posaconazole treatment with septic revision surgery was performed. However the disease ran a rapid course and was fatal two months after hospital admission.

CONCLUSION

This alarming result with extensive RM osteomyelitis in the proximal femur of an immunocompromised patient may hopefully warn medical staff to perform early imaging and aggressive surgical supported multimodal treatment in similar cases.

Disseminated Rhizopus microsporus infection following allogeneic hematopoietic stem cell transplantation in a child with severe aplastic anemia

Disseminated Rhizopus microsporus infections are uncommon in children and are resistant to echinocandin and azole antifungal agents. We describe a child with severe aplastic anemia who developed disseminated R. microsporus infection following allogeneic hematopoietic stem cell transplantation. R. microsporus was identified microscopically in the hepatic drain culture and was confirmed on the basis of 18S rRNA and 28S rRNA sequence analyses. The patient was treated successfully with hepatic drainage and amphotericin B deoxycholate.

Intestinal mucormycosis: a rare entity in pediatric oncology

Mucormycosis is increasingly emerging as an important cause of invasive fungal infection in immunocompromised patients. Intestinal mucormycosis is extremely rare, difficult to diagnose, and has dismal prognosis. We report two children with acute lymphoblastic leukemia and intestinal mucormycosis. Despite surgery and appropriate antifungal therapy, only one survived. Literature review showed only 10 other childhood cancer cases with intestinal mucormycosis. All had abdominal pain preceding gut perforation. All except one had leukemia and majority were in induction phase of therapy. Only 5 of these 12 children survived. Other than appropriate antifungal therapy, early surgery and rising neutrophils aid in recovery.

Antifungal therapy in children: an update

Invasive fungal infections are a common problem in children affected by primary or secondary immunodeficiencies. Thanks to an increased knowledge about their mechanisms of action and their pharmacokinetic and toxicity profiles, the use of these drugs in common and uncommon invasive infections in immunocompromised children has improved over the last decades. Choosing the most appropriate antifungal drug is a serious challenge for any clinician, also considering that, in most cases, therapy has to be started before cultures are available, the choice being driven by clinical symptoms and statistical criteria only. In this study, we performed a systematic review of literature, providing antifungal treatment recommendations for paediatric patients which can help clinicians find the most suitable treatment for each specific case. Principal antifungal drugs-ranging from first-generation antimycotics to the latest molecules-are classified according to their targets, and of each group, the pharmacokinetic profile, clinical indications and side effects are extensively described.

Mucormycosis treated with posaconazole: review of 96 case reports

Mucormycosis is an emerging invasive fungal infection, primarily affecting immunocompromised patients. The disease is difficult to diagnose and mortality reaches 40% even if treated adequately. Depending on site of infection and risk factors, surgical debridement in combination with systemically active antifungal drugs are the mainstay treatment strategies. Lipid-based amphotericin B is the treatment of choice for first-line therapy while posaconazole may be a promising alternative. We performed a PubMed search on reports of patients with mucormycosis treated with posaconazole. From 2003 to 2011, 96 cases have been published. Diagnosis was based on histology alone in 2 (2.1%) and microbiological evidence in 67 (69.8%), while no data on the diagnostic approach was reported in 27 (28.1%) patients. The most frequent pathogens were Rhizopus spp. (31.2%), followed by Mucor spp. (14.6%). The site of infection was predominantly rhino-orbital (38.5%, of which 43% also had central nervous system [CNS] involvement), followed by disseminated disease (22.1%). A complete response was achieved in 62 (64.6%), partial response in 7 (7.3%) patients, and stable disease in 1 (1%). Overall mortality was 24% (lacking data for three patients). In published case reports on posaconazole treatment for mucormycosis, the drug was frequently and successfully used in combination or as second line therapy.

Invasive mold infections: virulence and pathogenesis of mucorales

Mucorales have been increasingly reported as cause of invasive fungal infections in immunocompromised subjects, particularly in patients with haematological malignancies or uncontrolled diabetes mellitus and in those under deferoxamine treatment or undergoing dialysis. The disease often leads to a fatal outcome, but the pathogenesis of the infection is still poorly understood as well as the role of specific virulence determinants and the interaction with the host immune system. Members of the order Mucorales are responsible of almost all cases of invasive mucormycoses, the majority of the etiological agents belonging to the Mucoraceae family. Mucorales are able to produce various proteins and metabolic products toxic to animals and humans, but the pathogenic role of these potential virulence factors is unknown. The availability of free iron in plasma and tissues is believed to be crucial for the pathogenesis of these mycoses. Vascular invasion and neurotropism are considered common pathogenic features of invasive mucormycoses.

Caspofungin therapy in immunocompromised children and neonates

The prevalence of invasive fungal infections is increasing and the infections are becoming a major problem in immunocompromised children and neonates. Fortunately, there has been a recent surge in the development of new antifungal agents. Caspofungin, the first licensed echinocandin, is a novel class of antifungal and is approved for use in children 3 months of age or older for the treatment of invasive candidiasis, salvage therapy for invasive aspergillosis and as empirical therapy for febrile neutropenia. This article reviews the published data on the use of caspofungin in immunocompromised children and neonates with invasive fungal infections.

Posaconazole for the treatment of mucormycosis

Posaconazole (PCZ) is an orally administered, extended-spectrum triazole antifungal agent with activity against the Mucorales. This article describes the clinical and laboratory data supporting its use against this rare group of pathogens. To date, PCZ has been mostly used for salvage therapy and at present there is no strong published clinical evidence to support its role as a single agent in the treatment of mucormycosis. Further studies are required to explore its role as a single agent and in combination therapy for the management of these infections.

Lessons from animal studies for the treatment of invasive human infections due to uncommon fungi

Clinical experience in the management of opportunistic infections, especially those caused by less common fungi, is, due to their rarity, very scarce; therefore, the most effective treatments remain unknown. The ever-increasing numbers of fungal infections due to opportunistic fungi have repeatedly proven the limitations of the antifungal armamentarium. Moreover, some of these fungi, such as Fusarium spp. or Scedosporium spp., are innately resistant to almost all the available antifungal drugs, which makes the development of new and effective therapies a high priority. Since it is difficult to conduct randomized clinical trials in these uncommon mycoses, the use of animal models is a good alternative for evaluating new therapies. This is an extensive review of the numerous studies that have used animal models for this purpose against a significant number of less common fungi. A table describing the different studies performed on the efficacy of the different drugs tested is included for each fungal species. In addition, there is a summary table showing the conclusions that can be derived from the analysis of the studies and listing the drugs that showed the best results. Considering the wide variability in the response to the antifungals that the different strains of a given species can show, the table highlights the drugs that showed positive results using at least two parameters for evaluating efficacy against at least two different strains without showing any negative results. These data can be very useful for guiding the treatment of rare infections when there is very little experience or when controversial results exist, or when treatment fails.