Lung - nontumor

Author: Elliot Weisenberg, M.D. (see Authors page)

Revised: 27 February 2017, last major update September 2011

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

PubMed search: Rhodococcus [title] pulmonary

Cite this page: Rhodococcus. website. Accessed December 13th, 2018.
Clinical features
  • Zoonotic infection originally identified in lungs of foals; also cattle, swine, sheep, deer, goats, dogs, cats, other species
  • Worldwide distribution in water and soil, especially near feces of herbivores
  • Infection by inhalation or ingestion
  • Resides primarily within lung macrophages of infected patients, also some alveolar cells (Microbes Infect 2011;13:438)
  • R. equi is most common human pathogen of the Rhodococci
  • Generally occurs in AIDS patients (may cause malakoplakia, Clin Infect Dis 1999;28:1334); also other immunodeficient patients; very rarely in immunocompetent
  • Incidence decreasing, likely due to HAART therapy and azithromycin prophylaxis
  • "Rhodo" since salmon pink pigment in culture
  • Treated with antibiotics, but mortality is 50% in AIDS patients, 20% in other immunocompromised and 10% in immunocompetent
Case reports
Gross images

Images hosted on other servers:

Pulmonary mass in patient post renal transplant

Microscopic (histologic) description
  • Epithelioid macrophages containing gram positive, partially acid fast coccobacilli that resemble mycobacteria
  • May produce malakoplakia
Microscopic (histologic) images

Images hosted on other servers:

Various images

Figures 2 / 3: gram stain; 4: autopsy