Misdiagnosis analysis of 40 cases of focal organizing pneumonia

Objective To discuss the clinical manifestations, pathological features and imaging features of focal organizing pneumonia (FOP) in order to improve the understanding of the disease among clinicians. Methods The clinical data of 40 patients with FOP misdiagnosed as lung cancer in the People′s Hospital of Jiangsu Province from 2013 to 2018 were retrospectively analyzed.The clinical manifestations, pathological features, imaging features, laboratory tests were analyzed. Results (1)Of the 40 patients with FOP, 34 cases were male, six cases were female, the age was 26-82 years old, and the average age of onset was (55.55± 10.52) years old.(2)In clinical manifestations, there were 21 cases of cough and expectoration, six cases of fever, 11 cases of hemoptysis, 12 cases of chest pain, and 14 cases had no any symptoms.(3)The lesions occurred in the field, middle and inner zones and in the lobes of the lungs.CT manifestations were varied.In addition to nodular shadow and solid change, there were lobulation, marginal burr sign, bronchial inflation sign, vacuole sign, uneven density, pleural traction and so on.There were 26 cases with lesions larger than 3 cm and 14 cases with lesions less than 3 cm.(4)A total of 8 patients underwent PET-CT examination, six patients showed different degrees of increased fluorodeoxyglucose metabolism, suggesting malignant lesions, two cases did not see increased fluorodeoxyglucose metabolism, considering inflammatory changes.(5)Among 40 patients, carcinoembryonic antigen, carbohydrate antigen199 and D-dimer were normal, neuron-specific enolase was increased in only one case.(6)Pathology results showed interstitial fibroplasia, alveolar cavity expansion, fibrous mucoid plug in the cavity, interstitial lymphocytic infiltration with lymphoid follicle formation.(7)Among the 40 surgical patients, one patient recurred after half a year. Conclusions FOP is relatively rare in clinic.Because of its special imaging manifestations, it is easily misdiagnosed.Clinicians need to constantly strengthen their understanding of FOP, and make comprehensive diagnosis through basic information, clinical manifestations, imaging performance, laboratory examination and pathological features, so as to reduce clinical misdiagnosis. Key words: Focal organic pneumonia; Clinical manifestations; Pathological features; Imaging features; Diagnostic errors