A 65-year-old man comes to the office due to a persistent dry cough for 6 months. During this time period, he has also had fatigue and a 4.5-kg (10-lb) weight loss. The patient has no history of serious illness and does not take any medications. He has smoked one pack of cigarettes daily for 35 years. Physical examination reveals decreased breath sounds and dullness to percussion at the left lung base. Imaging studies show an irregular mass in the lower lobe of the left lung and a left pleural effusion. A diagnostic thoracocentesis is performed and the aspirated fluid is sent for cytological evaluation. If a malignancy is diagnosed, it is most likely to be which of the following types?

Question

A 65-year-old man comes to the office due to a persistent dry cough for 6 months. During this time period, he has also had fatigue and a 4.5-kg (10-lb) weight loss. The patient has no history of serious illness and does not take any medications. He has smoked one pack of cigarettes daily for 35 years. Physical examination reveals decreased breath sounds and dullness to percussion at the left lung base.   Imaging studies show an irregular mass in the lower lobe of the left lung and a left pleural effusion.  A diagnostic thoracocentesis is performed and the aspirated fluid is sent for cytological evaluation.  If a malignancy is diagnosed, it is most likely to be which of the following types?

Quizplus · Accepted Answer

Eductional Objective: Adenocarcinoma is the most common primary lung cancer in the general population, women, and nonsmokers.  Epidermal growth factor receptor (EGFR) mutations and ALK gene rearrangements are seen more commonly in nonsmokers and thought to contribute to disease formation in this subgroup.  Adenocarcinoma is typically located peripherally and may be associated with clubbing or hypertrophic osteoarthropathy.

A 65-Year-Old Man Comes to the Office Due to a Persistent