Multidisciplinary interstitial lung disease (ILD) board: real life experience with 91 cases

Introduction and Background: ILD's are difficult to diagnose, to distinguish in their specific subtypes and to study because of their heterogeneity, overlapping clinical, radiological and pathological findings, and low prevalence. Multidisciplinary discussion is considered gold standard for diagnosis of idiopathic interstitial pneumonia (IIP) according to recent ATS/ERS guidelines (2013). Interdisciplinary discussion has proven to increase consensus diagnosis and to avoid further unnecessary exams (Flaherty, et al. AJRCCM 2004).

Methods: We retrospectively evaluated the characteristics and diagnostic outcomes of the patients discussed in our multidisciplinary board (MDB) for ILD during the last 2 years. Cases were discussed between clinicians, radiologists and pathologists.

Results: In total, 91 patients were assessed. 56% (51 cases) were referred by pulmonologists in private practice, 23% (21 cases) by general practitioners and 21% (19 cases) were internal hospital referrals. 66% had initially the diagnosis of unknown ILD, 23% suspicion of IPF, and 4.4% suspicion of hypersensitivity pneumonitis (HP). MDB discussion achieved a diagnosis in 72 patients (79%). In 67 patients (74%) the initially suspected diagnosis could be clarified (48%) or had to be modified (25%). 17 patients (19%) were diagnosed with IPF or NSIP each, 6 (6.5%) with sarcoidosis, 5 (5.4%) with HP, 4 (4.4%) with organizing pneumonia (OP). 2 patients (2.2%) were diagnosed with combined pulmonary fibrosis and emphysema (CPFE), Langerhans cell histiocytosis (LCH) and vasculitis each. Single cases (1.1%) included: Respiratory bronchiolitis ILD (RB-ILD), pulmonary lymphangioleiomyomatosis (LAM), Birt-Hogg-Dubé Syndrome and Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH).

Conclusions: After MDB discussion for ILD a consensus on diagnosis could be achieved in the majority of cases (79%) with 66% of patients initially referred for unknown ILD. Nineteen cases (21%) remained unclear or needed further evaluation. Unclassified IIP in our population is higher than currently reported (11% unclassified IIP. Theegarten et al. Diagnostic Pathology 2012). We believe this reflects our approach to discuss cases early during diagnostic process with MDB before eventual wedge resection, in order to direct or even avoid unnecessary invasive procedures. In addition the high number may be due to a selection bias, since only particularly difficult to diagnose cases are referred for MDB by pulmonologists in private practice asking for a second opinion. Our findings highlight the importance of early MDB in clinical ILD routine to improve diagnosis and facilitate treatment or further diagnostic work up.