Bronchogenic Carcinoma

Key Features

Essentials of Diagnosis

• New cough or change in chronic cough

• Dyspnea, hemoptysis, anorexia, weight loss

• Enlarging nodule or mass, persistent opacity, atelectasis, or pleural effusion on chest radiograph or CT scan

• Cytologic or histologic findings of lung cancer in sputum, pleural fluid, or biopsy specimen

General Considerations

• Leading cause of cancer deaths

• Cigarette smoking causes 85–90% of lung cancers

• Small cell lung cancer (SCLC) (13%)

  • Bronchial origin, begins centrally, and infiltrates submucosally

  • Prone to early hematogenous spread

  • Is rarely amenable to resection

  • Has a very aggressive course

• Non–small cell lung cancer (NSCLC)

  • Spreads more slowly

  • Early disease may be cured with resection

  • Histologic types

    • Squamous cell carcinoma (23%) arises from bronchial epithelium; it is usually centrally located and intraluminal

    • Adenocarcinoma (48%) arises from mucous glands or from any epithelial cell within or distal to terminal bronchioles; usually presents as peripheral nodules or masses

    • Adenocarcinoma in situ (formerly bronchioloalveolar cell carcinoma) spreads along preexisting alveolar structures (lepidic growth) without evidence of invasion

    • Large cell carcinoma (1.5%) is a heterogeneous group and presents as a central or peripheral mass

Demographics

• Median age at diagnosis in the United States is 70 years

• Environmental risk factors include

  • Tobacco smoke

  • Radon gas

  • Asbestos

  • Metals

  • Diesel exhaust

  • Ionizing radiation

  • Industrial carcinogens

• A familial predisposition is recognized

• Chronic obstructive pulmonary disease, pulmonary fibrosis, and sarcoidosis are associated with an increased risk of lung cancer

Clinical Findings

Symptoms and Signs

• Majority of patients are symptomatic at diagnosis

• Presentation depends on

  • Type and location of tumor

  • Extent of spread

  • Presence of distant metastases

  • Any paraneoplastic syndrome

• Anorexia, weight loss, and asthenia in 55–90%

• New or changed cough in up to 60%

• Hemoptysis in 5–30%

• Pain, often from bony metastases, in 25–40%

• Local spread may result in endobronchial obstruction and postobstructive pneumonia, effusions, or a change in voice due to recurrent laryngeal nerve involvement

• Superior vena cava (SVC) syndrome

• Horner syndrome

• Liver metastases are associated with asthenia and weight loss

• Possible presentation of brain metastases

  • Headache

  • Nausea and vomiting

  • Seizures

  • Dizziness

  • Altered mental status

• Paraneoplastic syndromes (eTable 39–1)

  • Syndrome of inappropriate antidiuretic hormone secretion occurs in 10–15% of SCLC patients

  • Hypercalcemia occurs in 10% of NSCLC patients