Clinical and Radiological Profile of Acute Fibrinous and Organizing Pneumonia: A Retrospective Study

Spontaneous regression of acute fibrinous organizing pneumonia induced by COVID-19 vaccination: A case report

A 42-year-old woman visited our hospital with complaints of fever, muscle pain, and dyspnea one week after receiving the coronavirus disease 2019 (COVID-19) vaccine. Chest high-resolution computed tomography showed a patchy consolidation and ground-glass attenuation in the both lungs, consistent with acute interstitial pneumonia. Transbronchial lung cryobiopsy revealed organizing pneumonia with marked intra-alveolar fibrin, and pathologically diagnosed as acute fibrinous organizing pneumonia (AFOP). Other causative diseases such as dermatomyositis was clinically ruled out, and COVID-19 vaccine-induced AFOP was diagnosed. Physician should check the history of COVID-19 vaccination when encountering a case of AFOP with an unknown cause.

Update on cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia (COP) is a form of idiopathic interstitial pneumonia that results from the pulmonary reaction to various unidentified injuries. Secondary organizing pneumonia is diagnosed when the triggering factor has been identified; it is mainly caused by infections, toxic substance exposure, drugs, connective tissue diseases, malignancies, autoimmune diseases, bone marrow, or organ transplantation, and radiotherapy. There has been an increase in the number of reports of drug-induced organizing pneumonia (OP). New biological therapies, interferon, monoclonal antibodies, anti-interleukin antibodies, and PD1/PDL-1 inhibitors may induce this specific pulmonary reaction. The classical form of COP is usually subacute and does not manifest as severe disease. Patients maintain sufficient respiratory function, and treatment with steroids is usually effective. Several specific forms of OP (e.g., the cicatricial variant or acute fibrinous type) have distinct clinical and histological features, require higher doses of immunosuppressive drugs, and have a worse prognosis. In the era of administering steroid-sparing therapies for the treatment of interstitial lung diseases, connective tissue dases, and other conditions, it is important to emphasize this type of therapy for patients with COP.

Clinical features and long-term prognosis of acute fibrinous and organizing pneumonia histologically confirmed by surgical lung biopsy

Background

Acute fibrinous and organizing pneumonia (AFOP) is a rare interstitial pneumonia characterized by intra-alveolar fibrin deposition and organizing pneumonia. The clinical manifestations and long-term prognosis of AFOP are unclear. Our objective was to investigate the clinical features and prognosis of AFOP.

Methods

We identified patients diagnosed with AFOP by surgical lung biopsy between January 2011 and May 2018 at Seoul National University Bundang Hospital. We retrospectively reviewed clinical and radiologic findings, treatment, and outcomes of AFOP.

Results

Fifteen patients with histologically confirmed lung biopsies were included. The median follow-up duration was 2.4 (range, 0.1–82) months. The median age was 55 (range, 33–75) years, and four patients were immunocompromised. Fever was the most common clinical presentation (86.7%). Patchy ground-glass opacities and/or consolidations were the most predominant findings on chest computed tomography images. Nine patients (60%) received mechanical ventilator care, and eight patients (53.3%) died. The non-survivors tended to have slightly higher body mass index (BMI) and a long interval between symptom onset and diagnosis than the survivors, but these findings were not statistically significant. Among seven survivors, five patients were discharged without dyspnea and oxygen supplement.

Conclusions

The clinical course of AFOP was variable. Although AFOP was fatal, most of the patients who recovered from AFOP maintained normal life without supplemental oxygen therapy and respiratory symptoms.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

Acute fibrinous and organizing pneumonia following hemophagocytic syndrome in two adult patients with hematological malignancies

Acute fibrinous and organizing pneumonia (AFOP) is a rare acute lung injury featuring pathological intra-alveolar fibrin balls and organizing pneumonia without hyaline membranes or eosinophils. AFOP forms acute and subacute patterns; the former often has a poor prognosis, whereas the latter has better survival. Secondary hemophagocytic syndrome (HPS) is a cytokine-related and potentially lethal disorder induced by various diseases, and pulmonary involvement in HPS is not rare. However, to our knowledge, no report has addressed the association between secondary HPS and AFOP development. We report two cases of subacute AFOP following HPS in hematological malignancies.

Clinical features of acute fibrinous and organizing pneumonia: An early histologic pattern of various acute inflammatory lung diseases

Background

Acute fibrinous and organizing pneumonia (AFOP) is a rare histologic pattern of acute lung involvement with intra-alveolar fibrin deposition. However, the clinical significance of the pathological findings of AFOP remains unclear. This study aimed to explore the clinical significance of AFOP through a comprehensive clinical examination.

Methods

The medical records of patients with lung diseases accompanied by the pathological finding of intra-alveolar organization between January 2010 and December 2019 were retrospectively reviewed. The clinical and radiological findings were compared between the groups with and without the histologic pattern of AFOP.

Results

We identified 34 patients with AFOP (AFOP group) and 143 without AFOP (non-AFOP group). The underlying diseases of the AFOP group were as follows: 19 patients had cryptogenic organizing pneumonia (OP), 5 had connective tissue diseases, 3 had radiation pneumonitis, 3 had chronic eosinophilic pneumonia, 2 had myelodysplastic syndromes, and 2 had drug-induced pneumonia. Fever was more common, the time from symptom onset to biopsy was shorter, and the serum C-reactive protein level was higher in the AFOP group than in the non-AFOP group. On high-resolution computed tomography, 85% of patients had OP pattern, and halo sign was more common in the AFOP group. Corticosteroids were effective in 94% of the patients in the AFOP group; however, recurrences were more frequent, and a higher corticosteroid dose was needed during recurrence.

Conclusions

AFOP might be an early phase of a histologic pattern associated with known etiologies. In addition, it could be a marker indicating intense inflammatory diseases with a tendency of recurrence.

Chronic Lung Allograft Dysfunction: Review of CT and Pathologic Findings

Chronic lung allograft dysfunction (CLAD) is the most common cause of mortality in lung transplant recipients after the 1st year of transplantation. CLAD has traditionally been classified into two distinct obstructive and restrictive forms: bronchiolitis obliterans syndrome and restrictive allograft syndrome. However, CLAD may manifest with a spectrum of imaging and pathologic findings and a combination of obstructive and restrictive physiologic abnormalities. Although the initial CT manifestations of CLAD may be nonspecific, the progression of findings at follow-up should signal the possibility of CLAD and may be present on imaging studies prior to the development of functional abnormalities of the lung allograft. This review encompasses the evolution of CT findings in CLAD, with emphasis on the underlying pathogenesis and pathologic condition, to enhance understanding of imaging findings. The purpose of this article is to familiarize the radiologist with the initial and follow-up CT findings of the obstructive, restrictive, and mixed forms of CLAD, for which early diagnosis and treatment may result in improved survival. Supplemental material is available for this article. © RSNA, 2021.

SARS-CoV-2 organising pneumonia: 'Has there been a widespread failure to identify and treat this prevalent condition in COVID-19?'

Reviews of COVID-19 CT imaging along with postmortem lung biopsies and autopsies indicate that the majority of patients with COVID-19 pulmonary involvement have secondary organising pneumonia (OP) or its histological variant, acute fibrinous and organising pneumonia, both well-known complications of viral infections. Further, many publications on COVID-19 have debated the puzzling clinical characteristics of 'silent hypoxemia', 'happy hypoxemics' and 'atypical ARDS', all features consistent with OP. The recent announcement that RECOVERY, a randomised controlled trial comparing dexamethasone to placebo in COVID-19, was terminated early due to excess deaths in the control group further suggests patients present with OP given that corticosteroid therapy is the first-line treatment. Although RECOVERY along with other cohort studies report positive effects with corticosteroids on morbidity and mortality of COVID-19, treatment approaches could be made more effective given that secondary OP often requires prolonged duration and/or careful and monitored tapering of corticosteroid dose, with 'pulse' doses needed for the well-described fulminant subtype. Increasing recognition of this diagnosis will thus lead to more appropriate and effective treatment strategies in COVID-19, which may lead to a further reduction of need for ventilatory support and improved survival.

A case report of acute fibrinous and organizing pneumonia

RATIONALE

Acute fibrinous and organizing pneumonia (AFOP) is a newly evolving rare non-infectious lung pathology, characterized by intra-alveolar fibrin balls on histology. It is usually difficult to be diagnosed and mistaken for other lung diseases.

PATIENT CONCERNS

In this article, an interesting case about a male patient with a 15-day history of high-grade fever, chills, and no productive cough was presented. He was misdiagnosed as the lung infection early, but exhibited no response to the antibiotic therapy.

DIAGNOSIS

The diagnosis of AFOP was determined by the lung biopsy and pathology.

INTERVENTIONS

With the diagnosis of AFOP, all antibiotics were discontinued, and 40 mg methylprednisolone daily was given intravenously.

OUTCOMES

The patient responded well to the treatment with steroids.

LESSONS

AFOP is a rare lung disease characterized by bilateral basilar infiltrates and histological findings of organizing pneumonia and intra-alveolar fibrin in the form of "fibrin balls". Lung biopsy and histopathology were the most important diagnostic methods for the AFOP. Glucocorticoid was an effective drug for the treatment. Subacute patients of AFOP have excellent prognosis with corticosteroids.

Acute fibrinous organising pneumonia presenting as a cavitary lung lesion and treatment response to azithromycin

Acute fibrinous organising pneumonia is distinct from the classic diffuse alveolar damage, organising pneumonia and eosinophilic pneumonia. A 52-year-old woman presented with fever, productive cough, night sweats and left-sided pleuritic chest pain for a week. Physical examination was significant only for decreased breath sounds in the left infraclavicular area laterally. Imaging studies revealed a peripheral thick-walled left upper lobe cavitary lesion, left lower lobe consolidation and an enlarged subcarinal lymph node. She was treated with doxycycline for 10 days without improvement. Pertinent laboratory tests, microbiologic workup and fibre-optic bronchoscopy were non-diagnostic and a CT-guided left upper lobe lung biopsy revealed acute fibrinous organising pneumonia. She was treated with azithromycin with complete resolution of symptoms. To our knowledge, this is the first reported case of acute fibrinous organising pneumonia presenting as a cavitary lung lesion and the first with treatment response to azithromycin.

Update on Rare Idiopathic Interstitial Pneumonias and Rare Histologic Patterns

CONTEXT

- In 2013, the revised American Thoracic Society and European Respiratory Society classification of idiopathic interstitial pneumonias (IIPs) described 2 rare IIPs and 2 rare histologic patterns. Because of the rarity of the disease, there is limited evidence related to the histology. Because the rare histologic patterns are provisional criteria, no unanimous consensus on histologic diagnostic criteria has yet been reached.

OBJECTIVE

- To review the histologic features for rare IIPs and rare histologic patterns, and to provide diagnostic aids and discuss the differential diagnosis.

DATA SOURCES

- Published peer-reviewed literature and the authors' personal experience.

CONCLUSIONS

- Following the publication of the international consensus classification, evidence regarding rare IIPs and rare histologic patterns has accumulated to some extent, although to date the amount remains insufficient and further evidence is required. Because the diagnosis is sometimes challenging, a multidisciplinary approach represents the gold standard in reaching an accurate diagnosis for these rare disorders.

High-Resolution CT Findings of Obstructive and Restrictive Phenotypes of Chronic Lung Allograft Dysfunction: More Than Just Bronchiolitis Obliterans Syndrome

OBJECTIVE

The purpose of this article is to review the high-resolution CT characteristics of individual obstructive and restrictive chronic lung allograft dysfunction (CLAD) phenotypes to aid in making accurate diagnoses and guiding treatment.

CONCLUSION

Long-term survival and function after lung transplant are considerably worse compared with after other organ transplants. CLAD is implicated as a major limiting factor for long-term graft viability. Historically thought to be a single entity, bronchiolitis obliterans syndrome, CLAD is actually a heterogeneous group of disorders with distinct subtypes.

A case of herbicide-induced acute fibrinous and organizing pneumonia?

BACKGROUND

To improve the understanding of acute fibrinous and organizing pneumonia (AFOP), we present one case of AFOP proven by percutaneous lung biopsy along with clinical features, chest imaging and pathology.

CASE PRESENTATION

A 50-year-old man was admitted to our department after he was given empiric therapy for community-acquired pneumonia (CAP). The clinical symptoms of the patient were dry cough, chills, night sweats and high fevers. Chest computed tomography (CT) scan showed a high-density shadow in the right lung lobe, similar to lobular pneumonia. The patient was preliminarily diagnosed with community-acquired pneumonia; however, antibacterial treatment was ineffective. To confirm the diagnosis, we performed bronchoscopy and percutaneous lung biopsy; pathology was consistent with AFOP. After he was treated with glucocorticoids, the patient's symptoms were relieved, and the shadow seen on imaging dissipated during the follow-up period.

CONCLUSIONS

AFOP is a rare histopathological diagnosis that can be easily misdiagnosed. Clinicians need to consider the possibility of AFOP in the case of invalid antibacterial therapy.

An Unusual Presentation of Acute Fibrinous and Organizing Pneumonia

BACKGROUND Acute fibrinous and organizing pneumonia (AFOP) is a newly evolving rare non-infectious lung pathology, characterized by intra-alveolar fibrin balls on histology. It is often difficult to diagnose and is usually mistaken for other lung pathologies. We present an interesting case of AFOP with unusual radiologic findings and disease course. CASE REPORT A 56-year-old woman presented with a 1-day history of high-grade fever, chills, and profuse sweating. She was febrile to 101.2 degree Fahrenheit on presentation. On physical examination, she had decreased air entry in the left upper lobe of the lung. Laboratory testing showed a white cell count of 27,000 cells per microliter of blood with left shift. A chest radiograph showed a left upper lobe consolidation. Computed tomography (CT) of the chest without intravenous contrast showed advanced centrilobular emphysema and left upper lobe consolidation measuring 6.2×5.9 cm. The patient was started on antibiotics. She clinically improved and was discharged on oral antibiotics. After discharge, a trans-bronchial lung biopsy showed acute inflammatory cell infiltrate with intra-alveolar fibrin balls but no hyaline membrane formation or significant eosinophils. These findings were consistent with acute fibrinous and organizing pneumonia. However, she was subsequently lost to follow-up. CONCLUSIONS Our case adds to the literature a new and unusual finding of upper lobe infiltrates, in contrast to most cases presenting as bilateral lower lobe infiltrates. In our case, symptomatic improvement after antibiotic treatment suggests a possible role of antibiotics in management of this entity.

Acute fibrinous and organizing pneumonia: A report of 13 cases in a tertiary university hospital

INTRODUCTION

Acute fibrinous and organizing pneumonia (AFOP) is a rare diffuse pulmonary disease, but it is not yet known whether it is a distinct form of interstitial pneumonia or simply a reflection of a tissue sampling issue.

METHODS

Cross-sectional evaluation of clinical and radiological findings, treatments, and outcomes for patients with histologically confirmed AFOP at a tertiary university hospital between 2002 and 2015.

RESULTS

Thirteen patients (7 women, 53.8%) with a mean ± SD age of 53.5 ± 16.1 years were included. The main symptoms were fever (69.2%), cough (46.2%), and chest pain (30.8%). All patients presented a radiological pattern of consolidation and 5 (38.5%) had simultaneous ground-glass areas. Histology was obtained by computed tomography-guided transthoracic biopsy in 61.5% of cases and by surgical lung biopsy in the remaining cases. Several potential etiologic factors were identified. Eight patients (61.5%) had hematologic disorders and 3 had undergone an autologous hematopoietic cell transplant. Two (15.4%) had microbiologic isolates, 5 (38.4%) had drug-induced lung toxicity, and 2 (15.4%) were classified as having idiopathic AFOP. In addition to antibiotics and diuretics used to treat the underlying disease, the main treatment was corticosteroids, combined in some cases with immunosuppressants. Median survival was 78 months and 6 patients (46.2%) were still alive at the time of analysis.

CONCLUSION

Our findings for this series of patients confirm that AFOP is a nonspecific reaction to various agents with a heterogeneous clinical presentation and clinical course that seems to be influenced mainly by the severity of the underlying disorder.