A 57-year-old man comes to the physician because of a 2-month history of worsening shortness of breath with walking. He has not had any cough, fevers, or recent weight loss. He has hypercholesterolemia, for which he takes simvastatin, but otherwise is healthy. He smoked 2 packs of cigarettes daily for 35 years. On lung auscultation, there are reduced breath sounds at the base of the left lung. An X-ray shows a left pleural effusion and multiple nodular pleural lesions. Electron microscopy shows tumor cells with long and slender microvilli are joined by desmosomes. Which of the following is the most likely diagnosis?

Question

Quizplus · Accepted Answer

Eductional Objective: Malignant mesothelioma is malignant tumor that develops from mesothelial cells.  It is secondary to asbestos exposure and presents with progressive dyspnea, cough, and chest pain.  Unilateral pleural thickening or plaque formation is seen on imaging; pleural effusions are also common and may be hemorrhagic.  Histopathology reveals tumor cells with numerous long, slender microvilli and abundant tonofilaments.

A 57-Year-Old Man Comes to the Physician Because of a 2-Month