Malignant pleural effusion (MPE) as debut of cancer

<b>Introduction and Objective:</b> To evaluate the clinical manifestations, diagnostic techniques, histology and location of the primary tumor of patients with MPE as debut of cancer. <b>Methods:</b> 402 consecutive patients diagnosed of malignant pleural effusion as debut of cancer were studied retrospectively (2008-2013) in a multi-centric study. <b>Results:</b> median age 70 years, 241 males. Main symptoms were dyspnea 81.1%, chest pain 47.8%, cough 44.3%, weight loss 36.6%, extrathoracic symptoms 34%, fever 9.2 and hemoptysis 2.2%. The location of the primary tumor was: lung 53.5%, pleural 20.4%, gynecological 6.5%, haematological 6.5%, gastrointestinal 3.2%, breast 1%, urological 7.9%, unknown 1%. The histologycal type were: adenocarcinoma 58%, mesothelioma 18,9%, carcinoma 7.2%, lymphoma 5.2%, small cell 5%, non small cell 2.46%, squamous cell carcinoma 1.5%, leukemia 1.24% and sarcoma 0.5%. <b>Conclusions:</b> The MPE as a diagnosis of unknown primary tumor was more common in men of advanced age. The predominant symptom was dyspnea. The thoracentesis was higher diagnosis yield than the closed pleural biopsy. Pleural mesothelioma and lung adenocarcinoma histologic subtypes were the most common sites.