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Open Access Highly Accessed Case report

Reversed halo sign in pneumocystis pneumonia: a case report

Hiroshi Otera1*, Kimihide Tada1, Toshiyasu Sakurai1, Kimio Hashimoto2 and Akihiko Ikeda1

Author Affiliations

1 Department of Respiratory Medicine, Nishi-Kobe Medical Center 5-7-1, Kojidai, Nishi-ku, Kobe, 651-2273 Japan

2 Department of Pathology, Nishi-Kobe Medical Center 5-7-1, Kojidai, Nishi-ku, Kobe, 651-2273 Japan

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BMC Medical Imaging 2010, 10:26  doi:10.1186/1471-2342-10-26

Published: 23 November 2010



The reversed halo sign may sometimes be seen in patients with cryptogenic organizing pneumonia, but is rarely associated with other diseases.

Case presentation

We present a case study of a 32-year-old male patient with acquired immunodeficiency syndrome, who had previously been treated with chemotherapy for non-Hodgkin's lymphoma. A chest X-ray showed bilateral patchy infiltrates. High-resolution computed tomography revealed the reversed halo sign in both upper lobes. The patient was diagnosed with pneumocystis pneumonia, which was successfully treated with sulfamethoxazole trimethoprim; the reversed halo sign disappeared, leaving cystic lesions. Cases such as this one are rare, but show that the reversed halo sign may occur in patients who do not have cryptogenic organizing pneumonia.


Physicians can avoid making an incorrect diagnosis and prescribing the wrong treatment by carefully evaluating all clinical criteria rather than assuming that the reversed halo sign only occurs with cryptogenic organizing pneumonia.