Diagnostic procedures and clinico-radiological findings of acute fibrinous and organizing pneumonia: a systematic review and pooled analysis

Objectives: To evaluate the clinico-radiological findings of acute fibrinous and organizing pneumonia (AFOP) in the literature according to whether a surgical or non-surgical biopsy was performed, as well as to identify prognostic predictors. Methods: We searched the Embase and OVID-MEDLINE databases to identify studies that presented CT findings of AFOP and had extractable individual patient data. We compared the clinical and CT findings of the patients depending on whether a surgical or non-surgical biopsy was performed and identified survival predictors using a multivariate logistic regression analysis. Results: Eighty-one patients (surgical biopsy, n = 52; non-surgical biopsy, n = 29) from 63 studies were included. The surgical biopsy group frequently experienced an acute fulminant presentation (p =.011) and dyspnea (p =.001) and less frequently had a fever (p =.006) than the non-surgical biopsy group. The surgical biopsy group had a worse prognosis than the non-surgical biopsy group in terms of mechanical ventilation and mortality (both, p =.023). For survival analysis, the patients with the predominant CT finding of patchy or mass-like air-space consolidation survived more frequently (p <.001) than those with other CT findings. For prognostic predictors, subacute indolent presentation (p =.001) and patchy or mass-like air-space consolidation on CT images (p =.002) were independently associated with good survival. Conclusions: Approximately one-third of alleged AFOP cases in the literature were diagnosed via non-surgical biopsy, but those cases had different symptomatic presentations and prognosis from surgically proven AFOP. Subacute indolent presentation and patchy or mass-like air-space consolidation at the presentation on CT images indicated a good prognosis in patients with AFOP. Key Points: • Acute fibrinous and organizing pneumonia (AFOP) cases diagnosed via non-surgical biopsy had different symptomatic presentations and prognosis from surgically proven AFOP. • Subacute indolent presentation and patchy or mass-like air-space consolidation on CT images indicated a good prognosis in patients with acute fibrinous and organizing pneumonia.