Lung - nontumor

Topic Completed: 1 September 2011

Revised: 29 January 2019, last major update September 2011

Copyright: (c) 2003-2017,, Inc.

PubMed search: nocardia [title] pulmonary

Elliot Weisenberg, M.D.
Page views in 2019: 3,100
Page views in 2020 to date: 1,202
Cite this page: Weisenberg E. Nocardia. website. Accessed May 28th, 2020.
Clinical features
  • Ubiquitous saphrophyte; disease caused by inhalation or direct implantation into skin
  • More than 30 species with clinical significance (Clin Microbiol Rev 2006;19:259)
  • Opportunistic lung infection associated with transplantation, chemotherapy, immunosuppression, steroids
  • Disease is relatively uncommon in HIV likely due to sulfonamide prophylaxis directed against P. jeroveci; HAART treatment may be effective (Can J Infect Dis Med Microbiol 2009;20:e103)
  • Complication of alveolar proteinosis
Clinical images

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White colonies

Gross images

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Microscopic (histologic) description
  • Focal bronchopneumonia with microabscesses, variable histiocytic response and ill defined granulomas
  • If identified by anatomic pathologist, clinical microbiology laboratory should be notified as routine culture may not isolate the organism
Microscopic (histologic) images

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Small abscess

Nocardia brasiliensis

Gram stain

Modified acid fast stain
shows weakly acid fast
branching, filamentous bacilli

Positive stains
  • Modified acid fast, Fite, Gram stain and GMS
  • Gram stain: slender, slightly beaded, branching filamentous bacilli
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