Lung Infection, Mucormycosis

• • Infection occurs after inhalation of sporangiospores, germination in a hyphal form

  • Pulmonary infection occurs in immunocompromised persons, follows a fulminant pattern

  • Distinct clinical syndromes:

  • -Rhinocerebral infection: Direct extension in CNS from paranasal sinus infection

    -Cutaneous infection: Burn patients

    -GI infection: Children with protein-calorie malnutrition

    -Disseminated infection: Uremic patients receiving deferoxamine therapy

Epidemiology

• • Pulmonary fungal infections are rising due to widespread use of broad-spectrum antibiotics, immunosuppressive drugs, and HIV infection

  • Occur anywhere in world, some with characteristic endemic areas

  • Rhizopus arrhizus (most common), absidia species, rhizomucor species

  • -Infection occurs in patients with diabetes, leukemia, immunosuppression

    -Common in decaying fruit, vegetables, soil, and manure

Symptoms and Signs

• • Pulmonary infection: Fever, cough, pleuritic chest pain, hemoptysis

Imaging Findings

• • Chest film: 3 distinct patterns

  • 1. Limited disease with involvement of single lobe

    2. Diffuse or disseminated disease

    3. Endobronchial disease with obstruction and secondary bacterial infection

  • Chest CT scan: Characteristic halo sign, ring enhancement, and air-crescent sign

• • Demonstrating organism in symptomatic patients

  • No skin or serologic test

  • Fungi grow in culture as broad irregular nonseptate hyphae branch at 90-degree angles

  • Diagnosis most commonly made by histology

  • Sine qua non: Hyphal vascular invasion between internal elastic membrane and media of blood vessels causing thrombosis and infarction

• • Chest x-ray

  • Chest CT scan

  • Sputum microscopy and culture

• • Amphotericin B is standard treatment

  • Small group of patients have limited disease: Aggressive surgical resection + amphotericin B

  • Endobronchial form: Successful treatment with transbronchoscopic resection using laser therapy

Prognosis

• • Mortality is 90% despite best treatment; death from fungal sepsis, pulmonary dysfunction, and hemoptysis

  • Those surgically treatable: Mortality 50%

  • Endobronchial treatment is generally successful

References