대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Acute fibrinous and organizing pneumonia

Radiologic Findings

Initial chest radiograph (Fig.1) shows diffusely distributed tiny nodular opacities in both lung fields. Subsequent chest CT (Fig.2-3) scan shows randomly distributed tiny nodular and branching opacities in both lungs.
Chest radiograph taken two weeks later (Fig.4) shows more prominent nodular opacities, irregular consolidation, and diffuse GGO in both lung fields. Chest CT scan (Fig.5-6) also reveals diffuse GGO, reticular opacities and peribronchial consolidation in both lungs. Small amount of bilateral pleural effusion is also seen.

Brief Review

Acute fibrinous and organizing pneumonia (AFOP) was confirmed by VATS biopsy. Multifocal patchy intra-alveolar fibrin deposition, necro-inflammatory exudates, and fibroblastic proliferation with organizing pneumonia pattern were confirmed in the specimen.
AFOP is a rare idiopathic interstitial pneumonia (IIP) which is characterized by fibrin deposition, so called fibrin balls, and associated organizing pneumonia within alveolar spaces. Although AFOP does not meet the criteria for either diffuse alveolar damage or organizing pneumonia on histopathologic examination, it has not been clear whether AFOP is a new rare IIP or a variant of existing IIPs, such as diffuse alveolar damage and organizing pneumonia. Clinico-radiological manifestation of AFOP can be categorized into two patterns: diffuse alveolar damage and organizing pneumonia. In a series of 17 patients diagnosed as having AFOP, nine patients had fulminant respiratory failure and rapid progression to death similar to that of diffuse alveolar damage, whereas ten patients had subacute respiratory distress with subsequent recovery. In AFOP mimicking diffuse alveolar damage, CT scan shows diffuse ground-glass opacities and consolidation with basilar predilection, while a focal or diffuse parenchymal consolidation can be identified resembling pneumonia or organizing pneumonia on CT scan in AFOP mimicking organizing pneumonia. AFOP may be idiopathic or associated with collagen vascular disease, hypersensitivity pneumonitis, or drug exposure.

References

1. Beasley MB1 Franks TJ, Galvin JR, Gochuico B, Travis WD. Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant of diffuse alveolar damage. Arch Pathol Lab Med. 2002 Sep;126(9):1064-70.
2. Travis WD, Costabel U, Hansell DM, King TE Jr, Lynch DA, Nicholson AG, et al. An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classification of the idiopathic interstitial pneumonias. Am J Respir Crit Care Med. 2013 Sep 15;188(6):733-48.
3. Kligerman SJ, Franks TJ, Galvin JR. From the radiologic pathology archives: organization and fibrosis as a response to lung injury in diffuse alveolar damage, organizing pneumonia, and acute fibrinous and organizing pneumonia. Radiographics. 2013 Nov-Dec;33(7):1951-75.
4. Feinstein MB, DeSouza SA, Moreira AL, Stover DE, Heelan RT, Iyriboz TA, et al. A comparison of the pathological, clinical and radiographical, features of cryptogenic organising pneumonia, acute fibrinous and organising pneumonia and granulomatous organising pneumonia. J Clin Pathol. 2015 Jun;68(6):441-7.
5. Dai JH, Li H, Shen W, Miao LY, Xiao YL, Huang M, Cao MS, et al. Clinical and Radiological Profile of Acute Fibrinous and Organizing Pneumonia: A Retrospective Study. Chin Med J (Engl). 2015 Oct 20;128(20):2701-6.

Please refer to

Case 954

Keywords

Acute fibrinous and organizing pneumonia , Idiopathic interstitial pneumonia,