Nocardia in a bronchaolveolar lavage specimen

Abstract

A 77-year-old female patient presented with a 1 month history of hemoptysis, fevers, chest discomfort, and increasing dyspnea on exertion. Her past medical history was significant for coronary artery bypass graft surgery 2 year previously, mixed hyperlipidemia and Ménière's disease. A chest CT scan was performed and showed multiple lung nodules measuring up to 3 cm in diameter in both lungs. The imaging findings were interpreted as most consistent with pulmonary metastases. A CT-guided core biopsy showed no evidence of malignancy but showed organizing pneumonitis with suppurative granulomas. Stains for acid fast bacilli (Fite), fungi (Gomori's methenamine silver, GMS), and bacteria (Brown-Brenn Gram) were negative for organisms, and the biopsy findings were felt to represent either an infection or Wegener's granulomatosis. The patient was placed on levofloxacin treatment with slight improvement of her symptoms. Further laboratory work-up did not support Wegener granulomatosis and blood cultures were negative. No lesions were identified bronchoscopically and the bronchoalveolar lavage (BAL) fluid showed 3,112 nucleated cells per lL, 85% of which were neutrophils and 10% monocytes or macrophages. Cytologic examination of Papanicolaou-stained smears prepared from the BAL sediment showed no organisms but the GMS-stained smears showed weakly staining long, slender (about 1 micron di-ameter) branching organisms (Fig. C-1). A Fite stain was performed on an additional smear and showed no acidfast organisms. Gram stains performed in the microbiology laboratory showed gram-positive beaded branching filamentous organisms (Fig. C-2), which were acid-fast on a modified Kinyoun stain.

Nocardiosis diagnosed on bronchoalveolar lavage: Role of cytopathology

“…While Nocardia are more commonly opportunistic pathogens infecting immunosuppressed individuals, they may also infect immunocompetent patients (which accounts for about a third of cases) 7–9 . Risk factors include those with depressed immunity, such as following solid‐organ or hematopoietic stem cell transplant, those receiving long‐term corticosteroid treatment or other medications that suppress cell‐mediated immunity, patients with malignancies, diabetes, or acquired immunodeficiency syndrome (AIDS), and those with chronic lung disease, although sometimes no predisposing factors may be identified 5,6,10–13 …”

“…[7][8][9] Risk factors include those with depressed immunity, such as following solid-organ or hematopoietic stem cell transplant, those receiving long-term corticosteroid treatment or other medications that suppress cell-mediated immunity, patients with malignancies, diabetes, or acquired immunodeficiency syndrome (AIDS), and those with chronic lung disease, although sometimes no predisposing factors may be identified. 5,6,[10][11][12][13] While Nocardia can cause cutaneous infection from traumatic inoculation that may progress to the joints or bones, pulmonary infection is the most common presentation because the organisms are readily aerosolized. 12 Pulmonary nocardiosis can present as an acute, subacute, or chronic infection with signs and symptoms including pneumonia with fever, cough, dyspnea, or chest pain that can become complicated by cavitation, abscess formation, pleural effusion, or empyema.…”