pleural neoplasm (Monarch Disease Ontology term MONDO_0021065) is a benign or malignant neoplasm that involves the serous membrane that lines the lungs and thoracic cavity. Most pleural neoplasms are metastatic. Diffuse malignant mesothelioma is the most common primary malignant neoplasm of the pleura. Also known as: neoplasm of pleura, neoplasm of pleural cavity, neoplasm of the pleura, pleura neoplasm, pleura neoplasm (disease), pleura tumor, pleura tumour, pleural cavity neoplasm (disease).