대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Placental Transmogrification

Radiologic Findings

Fig 1. Chest PA shows diffuse hyperlucency of the right lung, collapsed right upper lobe abutting mediastinal shadow and localized nodular opacities in the right middle lung zone.
Fig 2-5. Axial and coronal CT images with lung window setting reveal bullous change of the right middle lobe and partial collapse of the right upper and lower lobes. There are irregular nodular opacities with cystic wall thickening in the peripheral portion of the right middle lobe. There are several thin-walled cysts in the right lower lobe.
Fig 6. Axial CT image with mediastinal window setting show nodular soft tissue lesion in the right interlobar area. The patient underwent endobronchial ultrasound-guided biopsy and the pathologic examination confirmed pulmonary placental transmogrification at 11 R station.

Brief Review

Pulmonary placental transmogrification is an unusual locally destructive lesion in the lung related to emphysematous bulla occurring in young patients. Histologically, placental transmogrification has a specific presentation characterized by the formation of placental villus-like papillary structures. The core of the papillae contains proliferating vessels, inflammatory cells, and fat. To date, fewer than 15 cases have been reported in the literature. Clinically, pulmonary placental transmogrification may be asymptomatic or associated with chronic obstructive lung disease, pneumothorax, bronchopneumonia, or respiratory distress. The origin and pathogenesis remain unknown. Pulmonary placental transmogrification is thought to be a reactive lesion secondary to emphysema, but a congenital origin has not been excluded. It is usually described in association with bullous emphysema, and the prognosis after surgical resection is excellent.

Kim et al. suggested that the image findings of placental transmogrification can be classified into three patterns: The most common pattern is the bullous emphysema pattern, followed by the thin-walled cystic lesion and nodule pattern. The third and rarest pattern is the solitary nodule pattern. Previous papers have also reported cases with other radiologic findings, with specific examples including consolidative lesion with bronchiectasis and progressive unilateral interstitial lung disease with micronodules and cysts. Cases with pneumothorax have also been reported. In addition to the typical findings of cystic lesion and nodule, Shin et al. observed two findings commonly found in many cases: the inclusion of nodular interlobular septal thickening and clustered interstitial nodules and vascular dilatation of the affected lung.

References

1. Fidler ME, Koomen M, Sebek B, et al. Placental transmogrification of the lung: a histologic variant of giant bullous emphysema

Keywords