Show 0 f FROM Ii I I I II I 1 0 ON N E i I nl 1 I J r rII II I CELL 7 I CELL CEL Diagnosis Biopsy A physician can only suspect that a tumor is malignant To be sure he or she must remove a portion of the tumor and have it examined under the microscope by a pathologist Normal abnormal The pathologist is trained to recognize tissues of many different types and to recognize abnormalities in these tissues abnormal abnormal ab air Because cells may look normal for many different reasons cancer being only one of these experience is an important important important im im- im- im factor in correct diagnosis Taking an adequate biopsy specimen requires both knowledge and experience When taken properly such a surgical excision adds little or orno orno orno no risk of inducing cancer spread A specimen may include the entire growth in the case of very small tumors In larger tumors the specimen must be taken from the edge of the tumor so that normal and malignant tissues are included and a comparison can be made between the two Special instruments such as asa asa asa a bronchoscope enable biopsies from tissues not easily accessible accessible accessible ac ac- ac- ac to the physicians physician's hands The small piece of tissue ie e removed in a biopsy is first fixed or treated with chemicals to fix it in fn a state stale as close as possible to the original and and then embedded in paraffin for slicing into inLo thin sections A large chunk of tissue cannot be be examined since light will not pass through it Many sections of tissue are then d it slid s with special i ica nd oxa m i in JU fer the microscope Malignant cells within a block of normal cells usually look very different One common difference is the presence of unusually large numbers of dividing cells Also some cells can be seen dividing into three or four rather than the normal two Many times however only the experience of the pathologist can tell the difference difference difference dif dif- dif dif- ference between normal and malignant Frozen Sections Sometimes a physician requires diagnosis in a very short time such as during an operation In such cases specimens of questionable tissues may be examined by hardening with freezing and a rapid microscopic examination Results from these frozen sections can be reported at once to the surgeon in the operating room helping to determine whether the tissue in question should be removed Although some question the absolute validity of frozen sections continue to tolISe use lISe them because they prefer to remove all suspicious tissue in one operation rather than subjecting the patient to another operation All AH frozen sections are usually followed up by routine paraffin sectioning to double check the original diagnosis With such a it is unlikely that the technique of frozen sections would have survived for long if it were inaccurate Aspiration tion removing biopsy a small plug of tumor with suction by means of a needle or syringe-is syringe used when possible to avoid larger biopsy It is of diagnostic value in experienced hands but requires the services of an expert pathologist for interpretation Negative reports must often be followed with more adequate biopsy Next week Diagnosis Diagnosis- Radiology |