Pulmonary Mucormycosis in a Diabetic Patient with HIV

In 1994, a 43-year-old woman was admitted to the hospital for acute lung infection and was subsequently diagnosed with HIV without any opportunistic infection. One month before admission, she developed fever, asthenia, cough, and polyuro-polydipsic syndrome with a 10-kg weight loss. The chest X-ray was normal. Clinical assessment showed hyperthermia (38.4°C), permanent cough, hemoptysis, anterior chest pain, and crackles in the right upper field. The chest X-ray revealed a systematic opacity in the right upper lobe. A computed tomographic scan showed a voluminous cavitation (56 × 64 mm) with a bronchus of drainage. The laboratory tests revealed type 2 diabetes (glycemia 28 mmol/l; serum HCO3 22 mmol/l; anti-GAD antibodies 0.51 units/ml [<1]; and C-peptide 2.3 ng/ml [0.9–4]). Her C-reactive protein level was 248 mg/l, and her blood cell count and electrolytes were in the normal range. Immunodeficiency was not severe (CD4 370/mm³) and her viral load was low (1,700 copies/ml). A bronchoscopy showed a diffuse mucosis thickening with congestion. Mycobacteriological culture from a transbronchial biopsy carried out a final diagnosis of mucormycosis. No other localization of mucormycosis was found.

Treatment involved systemic amphotericin B, surgical resection of the right upper lobe, and the strict glycemic control. One month later, the patient was afebrile and asymptomatic.

Mucormycosis is an opportunistic fungal infection commonly found in patients with neutropenia (immunosuppresive agents) and diabetes. Mucormycosis seldom occurs in AIDS patients, except in those with neutropenia or additional risk factors (1). Because of the aerobic nature of fungi, the rhinocerebral form is the most frequent (55%), followed by pulmonary localization (30%) (2). The disease is severe with vascular invasion, thrombosis, and necrosis. Diabetic subjects are predisposed to rhinocerebral location, whereas neutropenic subjects are susceptible to pulmonary or disseminated infections (3). Only 225 cases of pulmonary mucormycosis were reported, 56% of which were found in patients with diabetes (2). In neutropenic patients, the clinical presentation mimics pulmonary aspergillosis, a rapidly progressive pneumonia with diffuse infiltrates. Conversely, diabetic subjects develop a localized endobronchial form (4). In diabetic patients, the mechanisms of the disease involve the combined effects of hyperglycemia, ketosis, and acidosis. The fungistatic activity of serum is due to the transferrin, which reduces the free-iron available to the fungus for growth. Acidosis temporarily disrupts the ability of transferrin to bind iron. Since ketoreductase is available in the fungi, they can use ketone bodies in their metabolism (1). The mechanism is different in poorly controlled diabetes, owing to impaired chemotaxis and phagocytosis of neutrophils (1).

The diagnosis is difficult. The mucormycosis is usually fulminant and mostly discovered at autopsy (5). Overall mortality rate of pulmonary mucormycosis is ∼80%, depending on underlying disease, delay to diagnosis, and extent of the lesion. Mortality is lower in surgical compared with medical treatment (11 vs. 68%) (2). Optimal therapy requires control of the underlying disease, surgical resection, and systemic antifungal therapy (1,2,4).

In this particular case, diabetes was probably the underlying disease and the HIV status was an additional risk factor. Moreover, the HIV infection favored a misleading diagnosis such as opportunistic infection (tuberculosis, aspergillus, etc.) or neoplasia.

In conclusion, mucormycosis should be considered in nonimmunodeficient diabetic patients with acute lung disease with cavitation, because early diagnosis and aggressive management maximize the chances for cure.