Neoplasia Case Studies II


CASE 2: Small cell anaplastic ("oat cell") carcinoma of the lung with metastases


History:

A 56-year-old man has had a chronic cough for many years, but in the past few days has noticed that the sputum contains streaks of blood. You discover that he has an 85 pack/year smoking history. He has also gained about 10 kg in the past two months, mostly evident as truncal obesity. His vital signs show T 36.6 C, P 73, R 16, and BP 155/95 mm Hg. On physical examination, you palpate firm, enlarged lymph nodes in the cervical region bilaterally. His liver span also seems to be increased. Abdominal striae are present and the abdomen is enlarged, but without a fluid wave. He has a few small bruises on his arms.

Imaage 2.1:

The cytologic appearance of cells in the sputum is shown. Describe the appearance. The atypical cells present have marked hyperchromatism with very high N/C ratio. These cells are not very large.

Image 2.2:

This is the gross appearance of the lesion in the lung? How would you describe it? The off-white mass extends irregularly along the bronchovascular tree. There is no single large well-circumscribed mass.

Image 2.3:

This is the microscopic appearance of the lesion. Describe it. There are sheets of small blue cells with no features of normal pulmonary cells. The degree of anaplasia is marked.
  1. What procedures can you do to further discover the cause of his problems?

    2. Diagnostic procedures could include a chest x-ray, sputum cytology, and bronchoscopy.

  2. What environmental cause(s) could have contributed to his disease? What neoplasms are associated with what environmental etiologies?

    3. The probable environmental cause in his case was smoking. Other associations with chemical carcinogens include asbestos and mesothelioma, estrogens and endometrial carcinoma, vinyl chloride and hepatic angiosarcoma. Associations with radiation esposure include bone cancer, leukemias, and thyroid cancer.

  3. How do you explain his weight gain along with the physical findings? What usually happens to persons with a malignant neoplasm?

    4. Most patients with malignant neoplasms that are extensive have weight loss. In his case, the physical findings suggest a possible paraneoplastic syndrome. The oat cell cancer may be secreting an ACTH-like substance that is leading to increased glucocorticoid production and Cushing's syndrome, with skin findings of easy bruisability and striae, hypertension, glucose intolerance, and truncal obesity.

  4. How do you explain the lymph node findings? Name the ways that tumors can spread.

    5. The enlarged lymph nodes (and liver) suggest metastatic disease. Carcinomas like to spread via lymphatics, first to local nodes and then to distant sites. They may also spread hematogenously. Any tumor can spread by local extension. Tumors arising adjacent to mesothelial surfaces (particularly in ovary) can spread by "seeding" over the surface. Sarcomas like to spread via the bloodstream and less commonly via lymphatics.