Malignant Pleural Mesothelioma (MPM) Presenting as Hydropneumothorax.

An 86-year-old man presented with bilateral lower limb edema and was found to have hydropneumothorax on chest radiography. CT revealed a substantial pleural effusion and plaques. The patient had a history of working in a stone workshop, but the extent of asbestos exposure remained unknown. Thoracic drainage and subsequent thoracoscopic surgery confirmed the presence of biphasic malignant mesothelioma through pathological examination. Hydropneumothorax as a presentation of malignant pleural mesothelioma (MPM) is rare, with only a few similar cases reported. Remarkably, despite the coexistence of plural effusion and pneumothorax, the patient did not experience dyspnea. The examination also revealed tumor rupture and disruption of the pleura. Considering the possibility of MPM in patients with asymptomatic hydropneumothorax is essential for early diagnosis and appropriate management.