Pulmonary mucormycosis

Advances in the diagnosis of fungal pneumonias

INTRODUCTION

Fungal infections are increasingly encountered in clinical practice due to more favorable environmental conditions and increasing prevalence of immunocompromised individuals. The diagnostic approach for many fungal pathogens continues to evolve. Herein, we outline available diagnostic tests for the most common fungal infections with a focus on recent advances and future directions.

AREAS COVERED

We discuss the diagnostic testing methods for angioinvasive molds (Aspergillus spp. and Mucor spp.), invasive yeast (Candida spp. and Cryptococcus ssp.), Pneumocystis, and endemic fungi (Blastomyces sp., Coccidioides ssp., and Histoplasma sp.). The PubMed-NCBI database was searched within the past 5 years to identify the most recent available literature with dates extended in cases where literature was sparse. Diagnostic guidelines were utilized when available with references reviewed.

EXPERT OPINION

Historically, culture and/or direct visualization of fungal organisms were required for diagnosis of infection. Significant limitations included ability to collect specimens and delayed diagnosis associated with waiting for culture results. Antigen and antibody testing have made great strides in allowing quicker diagnosis of fungal infections but can be limited by low sensitivity/specificity, cross-reactivity with other fungi, and test availability. Molecular methods have a rich history in some fungal diseases, while others continue to be developed.

Pulmonary Mucormycosis in Chronic Lymphocytic Leukemia and Neutropenia

Pulmonary mucormycosis is a rare life-threatening fungal infection associated with high mortality. We present the case of a 61-year-old man with history of chronic lymphocytic leukemia who presented with fever and cough, eventually diagnosed with pulmonary mucormycosis after right lung video-assisted thoracoscopic surgery. The patient was successfully treated with amphotericin B and right lung pneumonectomy; however, he later died from left lung pneumonia.

Effect of uraemic status on immunofluorescence and enzyme-linked immunosorbent assays for detection of human herpesvirus type 8 antibodies

Our previous study showed that human herpesvirus type 8 (HHV-8) seroprevalence was significantly higher in patients with end-stage renal disease (ESRD) immediately after haemodialysis than in healthy controls based on an immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA). However, other studies indicated that ESRD patients and healthy controls had similar HHV-8 seroprevalence. This study aimed to investigate whether this discrepancy is due to the effect of uraemic status.Plasma samples from 162 ESRD patients, taken immediately before and after haemodialysis, and 162 age and sex matched healthy controls were analysed for HHV-8 antibodies using both IFA and ELISA.HHV-8 seropositivities based on IFA and ELISA, both before and after haemodialysis, were significantly greater in ESRD patients than in healthy controls (p < 0.008 for all comparisons). The seropositivities and antibody titres of ESRD patients obtained with IFA were similar before and after haemodialysis. Seropositivities based on ELISA were identical before and after haemodialysis. The seropositivities obtained with the IFA markedly exceeded those with ELISA in each group of subjects (p < 0.0001 for all comparisons).Uraemic status did not significantly affect the IFA or ELISA results for HHV-8 antibodies.

A rapidly progressing Pancoast syndrome due to pulmonary mucormycosis: a case report

Introduction

Pancoast syndrome is characterized by Horner syndrome, shoulder pain radiating down the arm, compression of the brachial blood vessels, and, in long-standing cases, atrophy of the arm and hand muscles. It is most commonly associated with lung carcinoma but rarely is seen with certain infections.

Case presentation

We present the case of a 51-year-old Caucasian man who had acute myeloid leukemia and who developed a rapidly fulminating pneumonia along with signs and symptoms of acute brachial plexopathy and left Horner syndrome. Also, a purpuric plaque developed over his left chest wall and progressed to skin necrosis. The skin biopsy and bronchoalveolar lavage showed a Rhizopus species, leading to a diagnosis of mucormycosis. This is a rare case of pneumonia due to mucormycosis associated with acute Pancoast syndrome.

Conclusions

According to our review of the literature, only a few infectious agents have been reported to be associated with Pancoast syndrome. We found only three case reports of mucormycosis associated with acute Pancoast syndrome. Clinicians should consider mucormycosis in their differential diagnosis in a patient with pulmonary lesions and chest wall invasion with or without neurological symptoms, especially in the setting of neutropenia or other immunosuppressed conditions. It is important to recognize this condition early in order to target therapy and interventions.

Chapter 7: zygomycosis

Zygomycosis (mucormycosis) is a rare but highly invasive infection caused by fungi belonging to the order Mucorales, which includes the genera Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces and Syncephalastrum. This type of infection is usually associated with hematologic diseases, diabetic ketoacidosis and organ transplantation. The most common form of presentation is rhinocerebral mucormycosis, with or without pulmonary involvement. Pulmonary zygomycosis is more common in patients with profound, prolonged neutropenia and can present as segmental or lobar infiltrates, isolated nodules, cavitary lesions, hemorrhage or infarction. The clinical and radiological manifestations are often indistinguishable from those associated with invasive aspergillosis. This article describes the general characteristics of pulmonary zygomycosis, emphasizing laboratory diagnosis, and illustrates the morphology of some lesions.

Usefulness of molecular biology performed with formaldehyde-fixed paraffin embedded tissue for the diagnosis of combined pulmonary invasive mucormycosis and aspergillosis in an immunocompromised patient

Immunocompromised patients who develop invasive filamentous mycotic infections can be efficiently treated if rapid identification of the causative fungus is obtained. We report a case of fatal necrotic pneumonia caused by combined pulmonary invasive mucormycosis and aspergillosis in a 66 year-old renal transplant recipient. Aspergillus was first identified during the course of the disease by cytological examination and culture (A. fumigatus) of bronchoalveolar fluid. Hyphae of Mucorales (Rhizopus microsporus) were subsequently identified by culture of a tissue specimen taken from the left inferior pulmonary lobe, which was surgically resected two days before the patient died. Histological analysis of the lung parenchyma showed the association of two different filamentous mycoses for which the morphological features were evocative of aspergillosis and mucormycosis. However, the definitive identification of the associative infection was made by polymerase chain reaction (PCR) performed on deparaffinized tissue sections using specific primers for aspergillosis and mucormycosis. This case demonstrates that discrepancies between histological, cytological and mycological analyses can occur in cases of combined mycotic infection. In this regard, it shows that PCR on selected paraffin blocks is a very powerful method for making or confirming the association of different filamentous mycoses and that this method should be made available to pathology laboratories.

Unusual Pulmonary Embolism Septic Pulmonary Embolism and Amniotic Fluid Embolism

BACKGROUND

Septic and amniotic fluid emboli are rare sources of pulmonary embolism (PE), so the present study sought to elucidate the background of these cases.

METHODS AND RESULTS

A total of 11,367 PE cases were identified from 396,982 postmortem examinations. The incidence of septic PE was 247 (2.2%) of the total. The origin of infection was found in 85.6% of the cases. Fungal embolus was detected more often than bacterial embolus. The most frequently detected fungus was aspergillus (20.8%). The primary disease associated with fungal embolus was leukemia (43.2%). The incidence of PE cases associated with pregnancy and/or delivery was 89 (0.8%) of the total PE cases. Among them, amniotic fluid embolism was found in 33 (73.3%) of 45 PE cases with vaginal delivery, and in 7 (21.2%) of 33 PE cases with cesarean delivery (p<0.0001).

CONCLUSION

Fungal embolus was more frequent than bacterial embolus, and leukemia was most frequent as the primary disease in cases of fungal embolus. The main cause of PE in cesarean section cases was thrombotic embolism, and the main cause in vaginal delivery cases was amniotic fluid embolism.

Combined medical surgical therapy for pulmonary mucormycosis in a diabetic renal allograft recipient

Mucormycosis is a rare opportunistic infection that complicates chronic debilitating diseases and immunosuppressed solid-organ transplant recipients. We present a case of life-threatening pulmonary mucormycosis in a diabetic renal allograft recipient who survived with reasonable renal function. Early recognition of this entity and prompt use of bronchoalveolar lavage (BAL) are critical to the outcome. Antifungal therapy combined with early surgical excision of infected, necrotic tissue appears to be the preferred course of action. Judicious withholding of immunosuppressants until fungemia cleared did not jeopardize allograft function.

Liposomal amphotericin B and surgery in the successful treatment of invasive pulmonary mucormycosis in a patient with acute T-lymphoblastic leukemia

Pulmonary mucormycosis is a usually fatal opportunistic infection in immunocompromised patients. We describe the first case of an adult patient with hematological malignancy and profound neutropenia to survive a disseminated pulmonary Rhizomucor pusillus infection. Early diagnostic procedures combined with high doses of liposomal amphotericin B and surgical resection may have contributed to the successful outcome.

The role of BAL in the diagnosis of pulmonary mucormycosis

Five patients with pulmonary mucormycosis diagnosed during life are described. All had underlying predisposing conditions: either posttransplant or hematologic malignancies. In all cases, the diagnosis was made using fiberoptic bronchoscopy. In three patients, BAL was diagnostic. In two of these patients, the diagnosis was made by identifying the typical hyphae of mucormycosis in the BAL fluid alone. Transbronchial biopsy was diagnostic in three patients. Treatment was based on IV antifungal chemotherapy together with surgical removal of involved lung tissue whenever feasible. The clinical outcome of these patients was dismal and was determined primarily by the underlying condition.