Metastatic cancer mimics interstitial lung disease. Cases when we need fast diagnosis and treatment.

Interstitial lung diseases (ILD) are a heterogeneous group of diseases and one of the differential diagnosis which have to be excluded during diagnostic procedures are malignancies. We will present four patients who were referred to our Department because of suspicion of interstitial lung diseases according to radiology finding. In one case only, one of the radiologist's differential diagnosis was pulmonary lymphangitic carcinomatosis. All four patients had exertional dyspnea and dry cough which are nonspecific and can be first manifestation of ILD or obstructive lung diseases. After diagnostic evaluation in three cases, diagnosis was pulmonary lymphangitic carcinomatosis due to metastatic lung adenocarcinoma and in one due to metastatic adenocarcinoma of unknown primary origin. Patients with lymphangitic carcinomatosis have poor prognosis without treatment and usually die because of respiratory failure. With these four cases we want to highlight importance of thinking about malignancies when we have patients with suspicion of interstitial lung disease especially when reticular pattern is present on chest X ray. We also wanted to show how important is radiology finding and multidisciplinary approach, and how radiologist's differential diagnosis can be very helpful in making decisions in further investigations and way of clinicians thinking.