A rare cause of dysphagia: malignant pleural mesothelioma in the posterior mediastinum.

A 69-year-old man presented to the emergency room with dysphagia and vomiting. A computed tomographic scan revealed a posterior mediastinal mass surrounding the lower portion of the esophagus. Endoscopic examination demonstrated narrowing of the lower esophagus without malignant mucosal lesions. Thoracoscopic biopsies of the mediastinal mass failed to yield a pathologic diagnosis. The hyaluronic acid concentration in the left pleural effusion was remarkably high (755 mg/L), which is a finding strongly suggestive of malignant mesothelioma. Four months after the initial admission, a subcutaneous nodule was found in the left chest wall and a biopsy was taken. The histopathologic and immunohistochemical findings of the biopsy were consistent with the diagnosis of pleural malignant mesothelioma.