대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Cytomegalovirus (CMV) Pneumonia

Radiologic Findings

Chest PA shows bilateral air-space consolidation and small nodular opacities. CT shows diffuse bilateral ill-defined small nodules and interlobular septal and intralobular interstitial thickenings, and multifocal areas of consolidation.

The diagnosis of CMV pneumonia was made based on the detection of CMV antibody and cytomegalic change with intranuclear or intracytoplasmic inclusion body from BAL fluid.

Brief Review

Cytomegalovirus (CMV) pneumonia is a relatively common and very serious complication in organ transplant recipients. In particular, CMV pneumonia is often seen in allogenic bone marrow recipients (15-30%) and very fatal (mortality, 80-85% after 50-60 days).
Two morphologic patterns have been described, the first and most common consisting of multiple, relatively well defined, hemorrhagic nodules, 0.1-1.5 cm in diameter scattered randomly throughout the parenchyma and separated by more or less normal lung. Histologically the nodules consist of foci of intra-alveolar hemorrhage, edema, and fibrin deposition accompanied by necrotic debris and acute and chronic inflammatory cells. Hyaline membranes can be seen, and a mononuclear cell interstitial infiltrate of variable severity is usually present. The second pattern affects most of parenchyma, with histologic features of either diffuse alveolar damage or interstitial pneumonititis. It has been speculated that the nodular form of disease results from hematogenous seeding of the lungs s from the an extrapulmonary source and that the diffuse type may represent either endogeneous pulmonary infection or an extension of the nodular form to involve more of the lung.
The most common radiographic findings are bilateral linear opacities (reticular pattern), ground-glass opacities, and parenchymal consolidation. Less common manifestations include small nodular opacities, a reticulonodular pattern, and lobar consolidation. In a report of 31 patients with CMV pneumonia after BMT, radiographic abnormalities consist of air-space consolidation in 12 (39%), linear opacities (reticular pattern) in 7 (23%), and GGO in 4 (13%); a combination of the three patterns were seen in 8 (26%). These abnormalities were first seen 26 to 270 days (median, 96 days) after transplantation, were bilateral in 22 patients and unilateral in 9, and most commonly involved the lower lung zones. In the current study, the most common CT findings were bilateral nodular or reticulonodular opacities and areas of air-space consolidation and GGO. In one investigation of eight patients, seven had a combination of linear opacities and parenchymal consolidation. All lesions were bilateral. The consolidation most commonly consisted of poorly marginated opacities that were predominantly peripheral in distribution. Pleural effusion was present in 4 cases and bilateral in three, which could be attributed to other cause, most commonly renal failure. Mediastinal or hilar lymph nodes were not enlarged. Although, the radiologic or CT findings were nonspecific or variable, in patients who have undergone bone marrow or solid organ transplantation, the diagnosis of CMV pneumonia should be considered, particularly when the CT scans demonstrate diffuse nodular or consolidations and reticular opacities.

References

1. Tamm M, Traenkle P, Grilli B, et al. Pulmonary cytomegalovirus infection in immunocompromised patients. Chest 2001;119:838-843
2. Olliff JFC, Williams MP. Radiological appearanaces of CMV infections. Clin Radiol 1989;40:463-467
3. Kang EY, Patz EF Jr, Muller NL. Cytomegalovirus pneumonia in transplant patients: CT findings. J Comput Assist Tomogr 1996;20:295-299

Keywords

Lung, Infection, immune related,