Clinical Topics Conference: Chapter 12, The Lung

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  1. Chronic Obstructive Pulmonary Disease
  2. Lung Cancer
  3. Usual Interstitial Pneumonitis
  4. Pneumocystis carinii pneumonia
Case 1: Chronic Obstructive Pulmonary Disease

Clinical vignette:
This was one of many hospitalizations for a 65 year old white male who was admitted because of increasing dyspnea and a cough productive of purulent sputum. On admission, arterial blood gases showed a pH of 7.13, p02 31, and pC02 91 on room air. Despite vigorous medical management, including intubation and the use of the respirator, the patient eventually became comatose and died.

Significant past medical history included smoking 3 packs per day of Winston cigarettes since age 12. There was a history of respiratory difficulty for the last 15 years before his death. During this time the patient had persistent cough with sputum production almost every day of the year and progressive dyspnea. Pulmonary functions studies during previous hospitalizations showed evidence of severe obstructive lung disease, and other clinical studies failed to demonstrate another specific pulmonary disease which could explain these abnormalities. A clinical diagnosis of chronic obstructive lung disease was established and, as is often the case the patient was felt to have probable components of both chronic bronchitis and emphysema.

Discussion Topics

  1. Define chronic bronchitis and emphysema.

  2. Describe the major types of emphysema.

  3. Discuss the pathogenesis of emphysema.

  4. What are the expected pulmonary function abnormalities in this patient?

  5. Define obstructive lung disease and restrictive lung disease; cite examples of each; and discuss the major differences in pulmonary function studies for these two groups of patients.
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Case 2: Lung Cancer

Clinical vignette:
A 68 year old white male with a long history of heavy cigarette smoking presented to his physician with complaints of cough, hemoptysis, and a 20 lb weight loss in the last 6 months. He was found to have a centrally located 3.0 cm right upper lobe mass on chest x-ray as well as massive right paratracheal and hilar lymphadenopathy. A chest x-ray taken two years previously was normal. CAT scan of the chest and abdomen confirmed the presence of a right upper lobe mass, as well as hilar and mediastinal lymphadenopathy and multiple nodules in the liver and adrenals.

The patient underwent fiberoptic bronchoscopy, which revealed an obstructing tumor at the right upper lobe orifice. Bronchial brushings and washings were obtained for cytologic examination and were interpreted as small cell carcinoma. A bronchial biopsy also contained small cell carcinoma, oat cell type.

The patient received chemotherapy and responded with a dramatic reduction in tumor bulk and appeared to be free of recognizable tumor at one year. Recurrent tumor was discovered 18 months later and the patient subsequently died with widespread disease.

Discussion Topics

  1. Discuss the major risk factors for development of lung cancer.

  2. Which tumors are usually central in location? Peripheral in location? Most closely associated with smoking?

  3. Define the term "coin lesion", discuss the differential diagnosis of coin lesion and describe the appropriate clinical work-up.

  4. Discuss the prognosis and treatment of lung cancer.
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Case 3: Usual Interstitial Pneumonitis (UIP)

Clinical vignette:
A 55 year old male presented with a 9 month history of progressive shortness of breath and a nonproductive cough. There was no history of multisystem disease, exposure to allergens, occupational exposures or injection of any drugs. A chest x-ray showed bilateral, asymmetric reticulonodular pulmonary infiltrates that were more evident at the lung bases. Pulmonary function studies showed evidence of mild to moderate restrictive lung disease and hypoxemia. Fiberoptic bronchoscopy was visually normal; transbronchial biopsy showed non-specific changes. An open lung biopsy was obtained and demonstrated histologic features of Usual Interstitial Pneumonitis (UIP).

Discussion Topics

  1. Define interstitial lung disease, and cite examples.

  2. What are the histopathologic features of usual interstitial pneumonitis (UIP)?

  3. Discuss the typical clinical presentation of UIP and compare this with the expected clinical presentation of acute interstitial lung diseases such as AIP or DAD.

  4. How does one establish a diagnosis of UIP?
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Case 4: Pneumocystis Carinii Pneumonia

Clinical vignette
A 34 year old homosexual drug abusing male presented to the Emergency Room with a six month history of persistent Herpes simplex proctitis, progressive shortness of breath, bilateral chest pain, and fever to 101oF-102oF. Admission chest x-ray showed evidence of bilateral interstitial lung infiltrates. Fiberoptic bronchoscopy demonstrated Pneumocystis carinii in the bronchoalveolar lavage (BAL) fluid, bronchial washings, and transbronchial biopsy. Smears and cultures for fungi and mycobacteria were negative. The patient was treated with appropriate antimicrobials and recovered. An HIV test during this admission was positive.

The patient subsequently had multiple admissions with his final admission occurring 1 year after diagnosis. During this final admission, fiberoptic bronchoscopy demonstrated pneumocystis carinii and cytomegalovirus inclusions in BAL fluid. Despite vigorous therapy, the patient expired.

Discussion topics

  1. Discuss the pulmonary complications that are seen in patients with AIDS (both infectious and neoplastic).

  2. Describe the typical clinical presentation and characteristic pathologic features of pneumocystis pneumonia.

  3. What organs are frequently involved by CMV infection in immunocompromised patients? What is the typical cytopathic effect (CPE) of CMV?

  4. Viral pneumonias have a different histology than bacterial pneumonias. Contrast and compare the characteristic histomorphology of bacterial vs. viral pneumonia.
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