key: cord-0073767-rp2r7eoj authors: García-Huertas, Daniela; López-Fernández, Alejandro; De Dios-Chacón, Inmaculada title: Acute fibrinous and organizing pneumonia() date: 2022-01-19 journal: Med Clin (Engl Ed) DOI: 10.1016/j.medcle.2021.04.017 sha: 564b945f6cc4a56bd05c48ea48d38b155359afd5 doc_id: 73767 cord_uid: rp2r7eoj nan Acute fibrinoid and organizing pneumonia (AFOP) is a rare but serious histological variety of acute lung injury (ALI) that sometimes responds to treatment. We report the case of a patient diagnosed with AFOP as a result of acute respiratory failure (ARF). A 70-year-old male patient, admitted to hospital in April 2020 for a 3/4-day history of dyspnoea at rest. In the targeted history-taking he reported dyspnoea on minimal effort during the previous 6 months. The following stand out in his personal history: HBP, obesity, hypercholesterolemia, ex-smoker (ICAT 40 packs/year), leukocytoclastic vasculitis and prostate cancer in 2013. Given the epidemiological context, the symptoms, and the chest X-ray (bilateral alveolar-interstitial infiltrate), SARS-CoV-2 infection was established as the first diagnostic hypothesis, although the nasopharyngeal swab PCR and the serology were negative. Despite initiating treatment protocol for Covid-19 (systemic corticosteroids and antibiotic therapy), progression was poor, requiring admission to the ICU and mechanical ventilation (MV). The patient experienced severe distress which prolonged his stay in the ICU for 2 months. SARS-CoV-2, atypical bacterial serology, HIV, IGRA, bronchial aspiration, bronchoalveolar lavage and echocardiography were negative. Simultaneously, a wide range of antibodies were requested, including rheumatoid factor, ANA, anti-DNA, ANCA, inflammatory myopathy and anti-glomerular basement membrane antibodies, which were also negative. Chest CT scan showed increased 'ground glass' density in most of the lung parenchyma and patchy alveolar consolidation areas. The study was completed with a surgical biopsy, reported as acute lung parenchymal injury leading to immature fibrosis, without hyaline membranes, with fibrinous exudate and foci of organizing pneumonia suggestive of AFOP. Given this diagnosis, methylprednisolone boluses (500 mg/24 h for 3 days) followed by 1 mg/kg/24 h were administered, with slow clinical improvement allowing withdrawal of MV. The patient is transferred to the ward, where cyclophosphamide was added; later replaced by mycophenolate mofetil. In spite of all this, no improvement was seen in 2 CT scan controls and the patient remained with dyspnoea at rest and oxygen therapy, dying 6 months after admission to a hospital for the chronically ill. This disease was described as a result of the analysis of 17 suggestive cases of ALI, submitted to lung biopsy, which showed organized intra-alveolar fibrin deposition, areas of orga- nizing pneumonia and patchy distribution. 1 Hyaline membranes, eosinophils, abscesses and granulomas must necessarily be absent for the diagnosis, which distinguishes it from classical interstitial lung diseases. The usual symptoms are dyspnoea, fever and cough. 1,2 Radiologically, there is a diffuse infiltrate and ground-glass image 3 and the diagnosis of certainty requires lung biopsy. 2, 3 There are idiopathic cases and cases secondary to infectious diseases, autoimmune diseases, neoplasms, transplants and toxins. 2 Acute forms are usually fulminant, while subacute forms have a better prognosis when treatment is established. 1 The need for MV was identified as the only adverse prognostic factor, but when there is an underlying disease, it is often responsible for the increased mortality. 2 Our case would correspond to a subacute, idiopathic form, which nevertheless had a fatal outcome that could be attributed to an established lung injury. AFOP is probably underdiagnosed given its similarity to other lung conditions. Its form of presentation means that it can be interpreted as a pneumonia refractory to antibiotic treatment 4 and its radiological pattern is comparable to that of any interstitial lung disease. The need for lung biopsy may cause a delay in diagnosis but it is of vital importance in cases such as this, as it may allow the patient to benefit from early treatment with steroids. There are no established recommendations regarding dose and treatment duration, finding variations from low doses to boluses of 250-1000 mg for 3 days. 3, 5 The regimen is usually prolonged for months or years to avoid recurrences, both in idiopathic cases 4 as well as in those secondary to autoimmune diseases. 3 Immunosuppressants such as mycophenolate mofetil, azathioprine and cyclophosphamide can be used in both acute and maintenance phases. 3, 5 In conclusion, this is a disease with high mortality, which should be considered in the context of ARF with unfavourable progression after ruling out the usual causes, in order to establish an effective treatment as soon as possible. This article has not received any type of funding. Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant of diffuse alveolar damage López-Fernández and I. De Dios-Chacón Medicina Clínica xxx (xxxx) xxx-xxx Acute fibrinous and organizing pneumonia. A report of 13 cases in a tertiary university Life after acute fibrinous and organizing pneumonia: a case report of a patient 30 months after diagnosis and review of the literature Acute fibrinous and organizing pneumonia masquerading as a lower respiratory tract infection: a case report and review of the literature Acute fibrinous and organizing pneumonia The authors declare that they have no conflict of interest.