A 69-year-old man comes to the physician because of a cough for the past 3 months. The cough is mostly dry, but the patient recalls a recent episode in which he coughed up mucus with dark red streaks. He has felt tired for the past few months. Over the past month, he has had poor appetite and a 5-kg (11-lb) weight loss. He also has occasional back pain, which has worsened in recent weeks. He has no recent travel history. He has smoked a pack of cigarettes daily for 30 years. Physical examination shows scattered wheezes bilaterally. Chest CT scan reveals a mass in the right lung. Light microscopy of the mass is shown below: Which of the following is the most likely diagnosis?

Question

A 69-year-old man comes to the physician because of a cough for the past 3 months. The cough is mostly dry, but the patient recalls a recent episode in which he coughed up mucus with dark red streaks. He has felt tired for the past few months. Over the past month, he has had poor appetite and a 5-kg (11-lb) weight loss. He also has occasional back pain, which has worsened in recent weeks. He has no recent travel history. He has smoked a pack of cigarettes daily for 30 years.   Physical examination shows scattered wheezes bilaterally.  Chest CT scan reveals a mass in the right lung.  Light microscopy of the mass is shown below:  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Eductional Objective: Adenocarcinoma, the most common pulmonary malignancy, is characterized histopathologically by invasive glandular cells with abundant cytoplasm and eccentrically placed nuclei; mucin production is common.  Imaging typically demonstrates a discrete mass or pneumonia-like consolidation at the periphery of the lung.

A 69-Year-Old Man Comes to the Physician Because of a Cough