A Case of Pulmonary Embolism with Sarcomatoid Malignant Pleural Mesothelioma with Long-Term Pleural Effusion

Background: Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that originates from pleural mesothelial cells. In recent years, with the development of asbestos related industries and the increase in air pollution, its incidence has been increased. The incidence of pulmonary embolism combined with sarcomatoid MPM is very low and the prognosis is extremely poor. We here report a case of a patient with long term of pleural effusion and finally diagnosed as pulmonary embolism with sarcomatoid MPM. Case: A 75-year-old male with a 30-year history of asbestos exposure was admitted to our hospital due to chest pain and difficulty in breathing after exercise. Radiologic examination revealed pleural effusion, computed tomography pulmonary angiography (CTPA) suggests pulmonary embolism, and we consider pleural effusion caused by pulmonary embolism. After anticoagulant therapy for pulmonary embolism and pleural puncture to reduce pleural effusion, the patient's symptoms improved. However, after that, the patient was still admitted to the hospital several times because of recurrent chest pain and dyspnea symptoms, and radiologic examination always showed unexplained pleural effusion. Finally, pathological and immunohistochemical examinations of the pleural biopsy specimens were performed, and the diagnosis was confirmed as sarcomatoid MPM. Conclusion: In summary, sarcomatoid MPM with pulmonary embolism is relatively rare, and the prognosis is poor. Clinicians need to be alert to its occurrence. When the first diagnosis is confirmed and the effect of targeted treatment is still not good, the possibility of other diseases should be considered. In clinical practice, pleural biopsy guided by PET-CT is a good choice for patients with sarcomatoid MPM who cannot tolerate open pleural biopsies or thoracoscopy. And patients should undergo pleural morphology and immunohistochemistry as soon as possible, which are helpful for timely diagnosis.