Weekly Chest CasesArchive of Old Cases

Case No : 97 Date 1999-09-04

  • Courtesy of Hak Hee Kim, MD, Seog Hee Park, MD / Kangnam St. Mary's Hospital., Seoul, Korea
  • Age/Sex 68 / F
  • Chief ComplaintMild fever and dyspnea for two days. Three months ago, she had been diagnosed as having a central lung cancer in left lower lobe with metastases to lower paraesophageal lymph nodes and brain. Radiation therapy was performed in the regional lung lesion including lower paraesophageal lymph nodes with posteroanterior direction. After the patient received 35 Gy for three weeks, mild fever and dyspnea developed.
  • Figure 1
  • Figure 2
  • Figure 3

Diagnosis With Brief Discussion

Diagnosis
Pneumocystis carinii pneumonia with sparing of irradiated lung zone
Radiologic Findings
1. Chest radiograph reveals diffuse and bilateral ground-glass haziness with consolidations in the both lungs, mainly in both lower lungs.

2. HRCT scans show diffuse ground-glass opacities with septal thickening in both lungs. However, the medial portions of bilateral lungs, which conform the previous radiation port, are relatively spared from the diffuse process.

3. Transbronchial lung biopsy and bronchoalveolar lavage were performed after HRCT. The specimen revealed Pneumocystis carinii on silver staining.

4. In spite of immediate medication and supportive therapy, the patient died of respiratory failure five days later.
Brief Review
1. PCP remains a formidable pathogen in the immunocompromised host despite effective treatment.

2. The incidence of PCP in immunocompromised patients who do not have AIDS has been increasing, with mortality in this population approaching 50%.

3. The most characteristic appearance on chest radiographs is the finding of diffuse bilateral interstitial infiltrates and/or ill-defined hazy consolidation.

4. HRCT findings are known as patchy bilateral ground-glass opacities, often central or perihilar.

5. In addition to diffuse and bilateral disease, a distinct mosaic pattern has been described, with areas of normal lung intervening between focal areas of parenchymal involvement.

6. In the patient we describe, the distribution of the radiographically visible PCP was atypical. The lungs that were included in the radiation port were spared. Infiltrates only appear in nonirradiated lung as the "photographic negative of post-radiation pneumonia" on chest radiograph and HRCT scans. It was clearly influenced by the radiation therapy.

7. Forrest previously reported two cases of PCP in which lung irradiated approximately 3 and 12 months earlier remained free of infiltrates. He suggested that the irradiated lung tissue did not support the growth of Pneumocystis carinii. The Pneumocystis organism is very sensitive to its environment. It has not been cultured and, with rare exception, is only found in the alveolar air spaces and nearby pulmonary interstitium.

8. The extreme sensitivity of the organism makes it likely that altered lung tissue might not support its growth. This is confirmed in cases where previously radiation has damaged certain lung fields. The fibrotic lung was almost free of disease while the rest of the lung was heavily infected at postmortem examination.

9. To our knowledge, only one case was reported by Panicek et al. in which radiation therapy had altered the distribution of PCP infiltrates developing during the therapy. Our case, and those reported by Panicek et al. and Forrest, document that Pneumocystis infiltrates may spare lung included in a radiation port either during the course of therapy or months after its completion.

10. It is unknown how frequently such sparing occurs, or whether such sparing occurs with organisms other than Pneumocystis carinii. However, the finding of "photographic negative of post-radiation pneumonia" is helpful to diagnose PCP in an immunocompromised patient.
References
1. Kennedy CA, Goetz MB. Atypical roentgenographic manifestations of Pneumocystis carinii pneumonia. Arch Intern Med 1992;152:1390-1398

2. Naidich DP, McGuinness G. Pulmonary manifestations of AIDS: CT and radiographic correlations. Radiol Clin North Am 1991;29:999-1017

3. Panicek DM, Groskin SA, Chung CT, Heitzman ER, Sagerman RH. Atypical distribution of Pneumocystis carinii infiltrates during radiation therapy. Radiology 1987;163:689-690

4. Stover DE. Pneumocystis carinii: an update. Pulm Perspect 1994;11: 3-5

5. Kuhlman JE. Pneumocystic infections: the radiologist's perspective. Radiology 1996;198:623-635

6. Forrest JV. Radiographic findings in Pneumocystis carinii pneumonia. Radiology 1972;103: 539-544

7. Kim HH, Park SH, Kim SC, Kim YS. Altered distribution of Pneumocystis carinii pneumonia during radiation therapy. Eur. Radiol. 1999;9: (in press)
Keywords
Lung, Infection, Fungal infection,

No. of Applicants : 22

▶ Correct Answer : 4/22,  18.2%
  • - 怨
  • - 怨
  • - 遺€ 源€嫄댁
  • - AZ vesalius Tongeren, Belgium Rudi Stokmans
▶ Semi-Correct Answer : 1/22,  4.5%
  • -
  • Top
  • Back

Each Case of This Site Supplied by the Members of KSTR.
Copyright of the Images is in the KSTR and Original Supplier.
Current Editor : Sang Young Oh, M.D., Ph.D Email : sangyoung.oh@gmail.com

This website is optimized for IE 10 and above.