Diagnosis of the case presented in the previous edition

RADIOLOGICAL DIAGNOSIS

Diagnosis of the case presented in the previous edition

Dany Jasinowodolinski^I; Gustavo de Souza Portes Meirelles^II; Nestor L Müller^III

^IRadiologist at the Fleury Center for Diagnostic Medicine, São Paulo (SP) Brazil

^IIPhD in Radiology from the Universidade Federal de São Paulo – UNIFESP, Federal University of São Paulo – São Paulo (SP) Brazil

^IIIFull Professor of Radiology at the University of British Columbia, Vancouver, British Columbia, Canada

Pulmonary infection with Pneumocystis jiroveci (P. carinii) in an HIV-positive patient

Comments

Pneumocystis jiroveci pneumonia (previously known as P. carinii pneumonia) is rare in immunocompetent patients. However, it is a frequent cause of morbidity and mortality in immunocompromised patients, especially in those infected with HIV. It occurs more commonly in patients with CD4 counts below 200 cells per mm³. Common symptoms include progressive dyspnea, cough (usually non-productive), and low fever. Pneumothorax is one of the most frequent complications.

The most common radiographic findings are bilateral perihilar interstitial changes that become homogeneous and diffuse with the progression of the disease. Other findings are single or multiple nodules, pneumatoceles, and pneumothorax. Pleural effusion and lymph node enlargement are uncommon. The imaging method of choice is computed tomography (CT), preferably high-resolution CT (HRCT), which is more sensitive and more specific than is simple X-ray. The most common HRCT findings are ground-glass opacities, which are found predominantly in the upper lobes, sometimes accompanied by septal thickening, and progress to acinar consolidations over the course of the disease. Cysts are seen in some patients. Small pneumothoraxes are more easily detected on CT scans than on X-rays.

In this patient, P. jiroveci pneumonia was the initial manifestation of acquired immunodeficiency syndrome. However, the patient did not know that he was HIV-positive, and the diagnostic hypothesis, which was subsequently confirmed, was formulated only after the CT scan had been performed.

References

1.Thomas CF Jr, Limper AH. Pneumocystis Pneumonia. N Engl J Med. 2004;350(24):2487-98.

2.Gruden JF, Huang L, Turner J, Webb WR, Merrifield C, Stansell JD, et al. High-resolution CT in the evaluation of clinically suspected Pneumocystis carinii pneumonia in AIDS patients with normal, equivocal, or nonspecific radiographic findings. AJR Am J Roentgenol.1997;169(4):967-75.

There were no readers correctly diagnosing the case presented in the March/April 2007 issue

Publication Dates

• Publication in this collection
  25 Sept 2007
• Date of issue
  June 2007