A 53-year-old man comes to the office due to 4 months of progressively worsening dyspnea. He has also had decreased appetite, weight loss, and nagging epigastric discomfort. The patient has a history of peptic ulcer disease treated with over-the-counter antacids. He has a 20-pack-year smoking history and has worked as a plumber for the past 30 years. Vital signs are within normal limits. Physical examination shows fingernail clubbing and bibasilar end-inspiratory crackles on lung auscultation. Chest x-ray shows atelectasis and bilateral pleural plaques over the diaphragm. Chest CT shows reticular opacities of the lower lung fields, multiple pleural plaques, and a round 6-cm cavitary mass in the right lower lung field. CT-guided biopsy of the mass is planned. Which of the following is the most likely finding on biopsy?

Question

A 53-year-old man comes to the office due to 4 months of progressively worsening dyspnea.  He has also had decreased appetite, weight loss, and nagging epigastric discomfort.  The patient has a history of peptic ulcer disease treated with over-the-counter antacids.  He has a 20-pack-year smoking history and has worked as a plumber for the past 30 years.  Vital signs are within normal limits.  Physical examination shows fingernail clubbing and bibasilar end-inspiratory crackles on lung auscultation.  Chest x-ray shows atelectasis and bilateral pleural plaques over the diaphragm.  Chest CT shows reticular opacities of the lower lung fields, multiple pleural plaques, and a round 6-cm cavitary mass in the right lower lung field.  CT-guided biopsy of the mass is planned.  Which of the following is the most likely finding on biopsy?

Quizplus · Accepted Answer

11ec25c8_d4a4_31a6_bc81_bd699bc402ac_MD0003_00 This patient's symptoms, imaging studies, smoking history, and asbestos exposure suggest likely bronchogenic carcinoma (lung cancer) in the setting of asbestosis. Asbestos exposure alone (without smoking) increases the risk of lung cancer by almost 6-fold. Smoking adds a synergistic effect, and smokers with asbestos exposure have an almost 59-fold increased risk of bronchogenic carcinoma. Occupations associated with asbestosis include plumbers, electricians, carpenters, construction workers, shipbuilders, and insulation workers. Although patients can be asymptomatic for 20-30 years after asbestos exposure, most develop progressive dyspnea; cough, sputum production, and wheezing are not typically present (unless there is concurrent chronic obstructive pulmonary disease). Physical examination frequently shows bibasilar, end-inspiratory crackles and fingernail clubbing as the disease progresses. Chest x-ray can show bibasilar reticulonodular infiltrates, honeycombing (cystic areas surrounded by interstitial infiltrates), and bilateral pleural thickening. High-resolution chest CT typically shows subpleural linear densities and parenchymal fibrosis. Almost 50% of patients have pleural plaques, which helps differentiate asbestosis from other causes of pulmonary fibrosis. pleural plaques Patients with asbestosis are at increased risk for lung cancer, which can present similarly with progressive dyspnea. However, a cavitary mass, as seen on this patient's CT, is not typical of asbestosis and suggests cancer, particularly given the patient's smoking history and weight loss. Similarly, asbestosis is the only known risk factor for malignant pleural mesothelioma. However, pleural mesothelioma typically presents as a unilateral pleural abnormality with a large pleural effusion on chest x-ray. In addition, bronchogenic carcinoma is more common in patients with asbestos exposure, especially smokers. Pleural plaques (seen on this patient's CT) are consistent with asbestosis but do not necessarily suggest mesothelioma (Choice F). (Choices B, C, and D) Patients with asbestos exposure are at increased risk for other malignancies such as cancers of the larynx, oropharynx, esophagus, biliary system, and kidney. However, lung involvement by metastatic gastrointestinal cancers is usually characterized by multiple pulmonary nodules rather than a single mass or pleural plaques, as seen in this patient. This patient's epigastric pain may be related to his underlying peptic ulcer disease or, less likely, to metastases from his bronchogenic carcinoma. (Choice E) Peritoneal mesothelioma is a rare disease linked to asbestos exposure. Patients typically develop abdominal pain and distension (due to possible ascites), early satiety, nausea, and weight loss. CT typically shows nodular peritoneal thickening with moderate-to-severe ascites. Educational objective: Asbestos exposure increases the risk of pulmonary fibrosis and malignancy. Bronchogenic carcinoma is the most common malignancy diagnosed in patients exposed to asbestos. Smoking acts synergistically with asbestos to further increase the risk of lung cancer. References: Asbestos, asbestosis, smoking, and lung cancer. New findings from the North American insulator cohort. (http://www.ncbi.nlm.nih.gov/pubmed/23590275)

A 53-Year-Old Man Comes to the Office Due to 4