A Case Study: Lung Cancer
A 46-year-old man who has been a heavy smoker since the age of 16 complained of weakness, difficulty in swallowing and a chronic cough. On physical exam his face showed acne and appeared congested, and he had an elevated blood pressure. His serum calcium level was elevated. A large mass was detected in the right lung by computed axial tomography (CT scan). A radiologist performed a fine-needle aspiration (FNA) for diagnosis by the pathologist. The diagnosis will determine whether further surgery is required; the surgeon may modify the type and extent of resection depending on the microscopic findings. Further, the microscopic evaluation of any tissue yields not only the precise diagnosis, but also predictive information about the extent and severity of the disorder. For example, if it were a squamous cell carcinoma, complete removal might be attempted; if the tumor was a small cell carcinoma, then radio- and chemo-therapy might be the treatments selected. Sometimes, additional special stains, such as ones using immunohistochemistry, assist in interpretation of the diagnosis, and help to explain patient symptoms. In addition, clinically unsuspected problems may be revealed by the pathologist's studies, using special laboratory techniques.
Cells can also be obtained for microscopic examination without recourse to surgery. Originally introduced for detection of female genital cancer - the "Pap smear", cytopathology principles are now applied to most other organ systems and their diseases using FNA and other methods for cell retrieval. For certain types of tissue, examination of cell aspirates can be just as rapidly diagnostic, and can replace frozen section biopsy.
Viewing FNA-extracted cells under