squamous cell cancers, cancers of neuroendocrine origin, muscle tumors and most melanomas. Besides suggesting likely sites, EM studies are useful in eliminating certain tumor types.
Polymerase Chain Reaction (PCR) This new method detects minute amounts of genetic material (DNA or RNA). PCR may detect abnormal DNA or RNA structures in the biopsy specimen. A few of these abnormalities are specific for certain cancers and, thus, will suggest the origin of the tumor.
