|Year : 2016 | Volume
| Issue : 1 | Page : 117-118
Pulmonary nocardiosis mimicking malignancy
J Taneja1, B Sen2, N Dang1
1 Department of Microbiology, Dr. Dangs Laboratory Pvt. Ltd, New Delhi, India
2 Department of Pathology, Dr. Dangs Laboratory Pvt. Ltd, New Delhi, India
|Date of Submission||31-Oct-2014|
|Date of Acceptance||06-May-2016|
|Date of Web Publication||15-Jan-2016|
Department of Microbiology, Dr. Dangs Laboratory Pvt. Ltd, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Taneja J, Sen B, Dang N. Pulmonary nocardiosis mimicking malignancy. Indian J Med Microbiol 2016;34:117-8
Nocardia species are Gram-positive, branching, filamentous aerobic bacteria causing infection in both immunocompetent and immunocompromised hosts amongst which pulmonary nocardiosis is the most common. However, infections due to Nocardia otitidiscaviarum appear to be rare compared with those caused by other species of Nocardia. Low incidence may be attributed to reduced pathogenicity or its lower prevalence in the soil compared with other Nocardia species.,
We report a case of cavitary pneumonia caused by N. otitidiscaviarum mimicking lung malignancy. A 55-year-old female patient presented with the complaints of intermittent, low-grade fever, cough with scanty sputum and haemoptysis for 2 weeks. The patient was not diabetic and had not received steroid therapy. The patient was successfully treated for pulmonary tuberculosis 3 years back.
X-ray chest showed multiple variables sized round soft tissue density lesions with amorphous calcifications in the right upper zone and small cavities in left lower zone. Computed tomography (CT) chest showed multiple well defined bilateral subpleural soft tissue densities, predominantly in lower lobes with evidence of calcification and cavitation in few of the lesions with a differential diagnosis of lung mass and chronic granulomatous disease. CT guided aspiration was done through the left lateral intercostal space to rule out malignancy and the aspirate yielded purulent matter. Pus sample was subjected to microbiological analysis. Culture showed colonies with a chalky white appearance after 48 h of incubation. Gram's stain and Ziehl–Neelsen modified stain of the colonies showed Gram-positive bacilli and acid-fast rod-shaped filaments, respectively [Figure 1]. The genotyping and characterisation confirmed it as N. otitidiscaviarum. Pulmonary infections due to N. otitidiscaviarum although rare but have been reported previously. The patient was treated with cotrimoxazole. The patient showed significant symptomatic improvement in 1-week. A regular follow up and repeat chest X-ray after 2 months showed partial regression of pulmonary lesions. The patient showed complete recovery in 6 months and the chest radiograph showed almost complete resolution of the lesion with residual fibrotic opacities.
|Figure 1: Acid fast filamentous bacteria stained using modified acid-fast stain|
Click here to view
Pulmonary nocardiosis may manifest like empyema necessitans, coexist with pulmonary and extrapulmonary tuberculosis or it may mimic relapse of tuberculosis after completion of antitubercular treatment.
Rapid and accurate identification of aerobic actinomycetes is of immense importance due to the high prevalence of resistance. Isolates of N. otitidiscaviarum complex are usually resistant to beta-lactams, including most broad-spectrum cephalosporins, ampicillin, amoxicillin-clavulanic acid and imipenem, but are usually susceptible to amikacin, the fluoroquinolones and sulphonamides. The purpose of this case report was to emphasise that Nocardia, although rare in Indian scenario can present with unusual pulmonary lesion mimicking lung malignancy. Such lesions should be subjected to imaging-guided histopathological sampling and thorough microbiological evaluation including Gram's stain, modified Ziehl–Neelsen stain and culture for Nocardia.
| ~ Acknowledgement|| |
Authors thank Dr. Shiva Prakash and Dr. Arunaloke Chakrabarti, Professor and In Charge, Centre of Advance Research in Medical Mycology, WHO collaborating Centre for Reference and Research of Fungi of Medical Importance, National Culture Collection of pathogenic Fungi and Head, Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, for their kind help in the final identification of the organism.
| ~ References|| |
Brown-Elliott BA, Brown JM, Conville PS, Wallace RJ Jr. Clinical and laboratory features of the Nocardia
spp. based on current molecular taxonomy. Clin Microbiol Rev 2006;19:259-82.
Betrán A, Villuendas MC, Rezusta A, Moles B, Rubio MC, Revillo MJ, et al.
Cavitary pneumonia caused by Nocardia otitidiscaviarum
. Braz J Microbiol 2010;41:329-32.
Ramamoorthi K, Pruthvi BC, Rao NR, Belle J, Chawla K. Pulmonary nocardiosis due to Nocardia otitidiscaviarum
in an immunocompetent host – A rare case report. Asian Pac J Trop Med 2011;4:414-6.
Saubolle MA, Sussland D. Nocardiosis: Review of clinical and laboratory experience. J Clin Microbiol 2003;41:4497-501.