Unclassifiable Interstitial Lung Disease (ILD). Why

Introduction: ILD compose a heterogeneous group of conditions demanding a multidisciplinary approach. However, a significant number of ILD cases must be labelled as ‘unclassifiable ILD’,common in fibrotic ILD Objective: To describe our patients showing unclassifiable ILD and the basis for diagnosis Methods: Retrospective descriptive study based on a database of patients assessed in ILD Specialized Unit and diagnosed with unclassifiable ILD (clinical, radiological and pathological findings did not suggest a specific diagnosis after assessment by an ILD multidisciplinary team) Results: 640 patients: 88 (14%), 55 ♂, 33 ♀, were diagnosed with unclassifiable ILD. Mean age: 70.85 ± 15.40 and 75.54 ± 10.36 in unclassifiable ILD cases. HRCT patterns:41 alternative diagnosis, 4 probable UIP, 11 indeterminate, 8 UIP, 11 NSIP, 13 other. 27 patients underwent bronchoalveolar lavage, 16 transbronchial biopsy and 1 surgical lung biopsy. Reasons for an unclassifiable ILD: old age (47), comorbidities (11), mild or stable disease (14), severe disease (4), patient declining surgical lung biopsy (2), and major discrepancies between clinical, radiological and pathological findings (10) Conclusions: A significant number of ILD cases are diagnosed as unclassifiable ILD, thus hindering pharmacological treatment. Survival is similar in patients with IPF or unclassifiable ILD. A greater use of antifibrotic therapy is advisable because most HRCT patterns present pulmonary fibrosis