Rare complication of bronchoesophageal fistula due to pulmonary mucormycosis after induction chemotherapy for acute myeloid leukemia: a case report

Pulmonary mucormycosis diagnosed by ultrasound guided percutaneous biopsy: A case series

Pulmonary mucormycosis is a rare but highly lethal fungal infection, usually affecting immunocompromised patients. Pulmonary mucormycosis was also a critical problem that complicated the later part of the clinical course of COVID-19 in India. Early diagnosis of the disease, combined with aggressive treatment, is crucial for patient survival. Fibreoptic bronchoscopy is a useful procedure for diagnosis of pulmonary mucormycosis, but image-guided percutaneous biopsy efficiently samples lesions abutting the chest wall. Biopsy is more yielding than cultures and imaging guided biopsy is required for lesions that cannot be microbiologically confirmed by fibreoptic bronchoscopy. We present a case series of four patients of pulmonary mucormycosis in whom ultrasound guided biopsy clinched the diagnosis. All the four patients were poor surgical candidates and underwent medical management with antifungal agents, and had successful clinical recovery and radiological resolution. Our case series illustrates the utility of ultrasound guided percutaneous biopsy as a diagnostic tool for sampling cavitatory disease due to pulmonary mucormycosis, when fibreoptic bronchoscopy failed to yield a diagnosis and the beneficial role antifungal agents as salvage therapy in poor surgical candidates.

Part 2: Mucormycosis: Focus on Therapy

INTRODUCTION

Mucormycosis (MCR) a rare but life-threatening infection occurs primarily in immunocompromised hosts. Mortality rates with invasive MCR are high (>30-50%), up to 90% with disseminated disease, but lower (10-30%) with localized cutaneous disease. Due to the rarity of MCR, randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy or in MCR cases refractory to or intolerant of LFAB. Early surgical debridement or excision play important adjunctive roles in localized invasive disease. Control of hyperglycemia in diabetic patients, correction of neutropenia and reduction of immunosuppressive therapy is critical for optimal survival.

AREAS COVERED

The authors discuss various therapeutic options for mucormycosis. A literature search of mucormycosis therapies was performed via PubMed (up to December 2022), using the key words: invasive fungal infections; mold; mucormycosis; Mucorales; amphotericin B; isavuconazole; posaconazole.

EXPERT OPINION

Randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy, in MCR cases refractory to or intolerant of LFAB. We encourage early surgical debridement or excision as adjunctive measures.

Mucormycosis: risk factors, diagnosis, treatments, and challenges during COVID-19 pandemic

Mucormycosis is a deadly opportunistic disease caused by a group of fungus named mucormycetes. Fungal spores are normally present in the environment and the immune system of the body prevents them from causing disease in a healthy immunocompetent individual. But when the defense mechanism of the body is compromised such as in the patients of diabetes mellites, neustropenia, organ transplantation recipients, and other immune-compromised states, these fungal spores invade our defense mechanism easily causing a severe systemic infection with approximately 45-80% of case fatality. In the present scenario, during the COVID-19 pandemic, patients are on immunosuppressive drugs, glucocorticoids, thus are at high risk of mucormycosis. Patients with diabetes mellitus are further getting a high chance of infection. Usually, the spores gain entry through our respiratory tract affecting the lungs and paranasal sinuses. Besides, they can also enter through damage into the skin or through the gastrointestinal route. This review article presents the current statistics, the causes of this infection in the human body, and its diagnosis with available recent therapies through recent databases collected from several clinics and agencies. The diagnosis and identification of the infection were made possible through various latest medical techniques such as computed tomography scans, direct microscopic observations, MALDI-TOF mass spectrometry, serology, molecular assay, and histopathology. Mucormycosis is so uncommon, no randomized controlled treatment studies have been conducted. The newer triazoles, posaconazole (POSA) and isavuconazole (ISAV) (the active component of the prodrug isavuconazonium sulfate) may be beneficial in patients who are refractory to or intolerant of Liposomal Amphotericin B. but due to lack of early diagnosis and aggressive surgical debridement or excision, the mortality rate remains high. In the course of COVID-19 treatments, there must be more vigilance and alertness are required from clinicians to evaluate these invasive fungal infections.

Case Report: Metagenomics Next-Generation Sequencing Can Be Performed for the Diagnosis of Disseminated Mucormycosis

Mucormycosis is an infection caused by a group of filamentous molds with in the order Mucorales. In developing countries, most cases of mucormycosis occur in persons with poorly controlled diabetes mellitus or subjects with normal post-traumatic immune function. Mucormycosis exhibits a marked propensity for invading blood vessels. The mortality rate of invasive mucormycosis is very high (>30-50%), and 90% of mortality is related to disseminated diseases. We report a 62-year-old man with underlying diseases, such as diabetes and psoriatic arthritis, with a history of trauma before admission. Chest CT showed multiple cavities. Based on the suspected clinical manifestation of mucormycosis infection, the patient received a microbiological culture of bronchoalveolar lavage fluid, and metagenomics next generation sequencing (mNGS) was performed. The results suggested Klebsiella pneumoniae infection. However, Rhizopus microsporus strains were shown by the mNGS of transpulmonary puncture tissue. Therefore, we report a case in which rare pathogens are identified by mNGS.

Diagnosis of oesophageal mucormycosis managed with medical therapy alone

Mucormycosis is an invasive mould that can cause aggressive infection, particularly in immunocompromised patients. Though oesophageal mucormycosis is relatively rare, it remains an elusive and devastating manifestation of this disease. The management is also challenging, due to surgical morbidity and contraindications such as thrombocytopenia in immunocompromised hosts. In this report, we present the case of a 60-year-old Lebanese man with newly diagnosed acute myeloid leukaemia who developed oesophageal mucormycosis after induction chemotherapy with idarubicin/cytarabine (7+3). The diagnosis was made when the patient developed febrile neutropenia and odynophagia. CT scan of the chest revealed a thickened oesophagus. Oesophagogastroduodenoscopy with biopsy, histopathology and PCR were performed, resulting in the diagnosis of Rhizopus microsporus The patient was successfully treated with liposomal amphotericin B and salvage posaconazole therapy without surgical intervention. We reviewed the clinical characteristics of the six published oesophageal mucormycosis reports from the literature.