Acute fibrinous and organizing pneumonia: two case reports and literature review

Abstract

Background Acute fibrinous and organizing pneumonia (AFOP) is a rare histologic interstitial pneumonia pattern characterized by the intra-alveolar fibrin deposition and organizing pneumonia. Its clinical characteristics are still not well known and there is no consensus on treatment yet. Case presentation We report two female cases in their fifties diagnosed with AFOP confirmed by a second lung biopsy. Case 1 was idiopathic AFOP with manifestation of 6-week fever, dyspnea, and cough, while case 2 was secondary to systemic lupus erythematosus and fever was the major symptom. Their chest CT scans revealed bilateral multiple consolidations, predominantly in the lower lobes. Both cases were initially diagnosed with pneumonia, but did not improve after treatment with broad-spectrum antibiotics. In both cases, transbronchial biopsy and bronchoalveolar lavage fluid examination were inconclusive and the pathological diagnosis was confirmed by percutaneous lung biopsy. Both patients had a good clinical response to prednisone. Conclusions We report two rare AFOP cases to highlight the importance of awareness of this disease. We further perform the most comprehensive review to date in AFOP, including 150 patients since 2002. Consolidation was the most common imaging pattern, followed by ground-glass opacity and nodules. A lung biopsy is required for a definitive diagnosis. Corticosteroids is recommended as the most effective therapy, but treatment options should depend on the etiology and disease severity.

Two methods of lung biopsy for histological confirmation of acute fibrinous and organizing pneumonia: A case report

“…The dominant histological pattern of AFOP is intra-alveolar fibrin deposition and OP without the presence of classical hyaline membranes and eosinophilia, differentiating the disease from diffuse alveolar damage (DAD), OP, and eosinophilic pneumonia[ 1 , 2 ]. Two forms of the disease are described: An acute form with a fulminant course and rapid progression to respiratory failure, and a subacute form with a better outcome[ 1 , 3 ]. AFOP can be idiopathic or associated with a variety of disease conditions, including infections, collagen vascular diseases, adverse drug or chemical reactions, hematological malignancy, altered immune status, inhalation disease, and occupational or environmental exposures[ 4 - 10 ].…”

“…The most common radiological findings are diffuse, patchy opacities with both peripheral and bilateral distributions, and the lesions may be limited to the lung bases[ 1 ]. Chen et al [ 3 ] suggested that consolidation is manifested more frequently in patients with idiopathic AFOP, while converse ground-glass opacity is seen more frequently in patients with secondary AFOP.…”

“…Chen et al [ 3 ] suggested that surgical biopsy is the best choice for tissue sampling for AFOP diagnosis, as it can minimize the missing areas of the hyaline membrane in DAD. However, our patient showed no tolerance to the operation.…”

“…The most common symptoms are dyspnea, cough and fever, which often lead to misdiagnosis and delayed diagnosis. According to the literature, most cases were initially misdiagnosed as pneumonia and lung tumors[ 3 , 4 ]. Beasley et al [ 1 ] described a mean time from onset of symptoms to diagnosis of 19 d, and Gomes et al [ 4 ] reported a mean time of 43.9 d. A definitive diagnosis of AFOP requires histopathological evaluation[ 1 , 2 ].…”

“…Beasley et al [ 1 ] described a mean time from onset of symptoms to diagnosis of 19 d, and Gomes et al [ 4 ] reported a mean time of 43.9 d. A definitive diagnosis of AFOP requires histopathological evaluation[ 1 , 2 ]. Chen et al [ 3 ] suggested that surgical biopsy is optimal for tissue sampling to make an AFOP diagnosis. However, many patients showed no tolerance to the operation.…”