Diagnostic Methods for Neoplasia
|History and Physical Examination
||What the health care worker learns from talking to the patient and through direct examination may give clues to the presence of a neoplasm. Signs and symptoms such as weight loss, fatigue, and pain may be present. A mass may be palpable or visible.
||The use of plain films (x-rays), computed tomography (CT), magnetic resonance imaging (MRI), mammography, and ultrasonography (US) may be very helpful to detect the presence and location of mass lesions. The findings from these methods may aid in staging and determination of therapy.
||General findings such as anemia, enzyme abnormalities (such as an increased alkaline phosphatase), and hematuria or positive stool occult blood are helpful to suggest further workup. Tumor markers in serum such as carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), or human chorionic gonadotropin (HCG) can be performed. Unfortunately, they are not all that specific or sensitive, particularly when applied as screening tests to a general population. More specific testing, such as measurement of prostate specific antigen (PSA) levels, may help to determine the presence of specific neoplasms, but such tests are not perfect screening tools in a general population.
||Genetic markers include chromosomal alterations (translocations, deletions, duplication, etc.); specific gene defects; single nucleotide polymorphisms, and gene rearrangements. Detection of specific genes (such as BRCA-1 for breast cancer) may suggest an increased risk for some malignancies.
||Methods that sample cells can be simple and cost-effective and minimally invasive. A good example is the Pap smear for diagnosis of cervical dysplasias and neoplasms. Cells exfoliated into body fluids may also be examined. Fine needle aspiration (FNA) can be used to sample a variety of mass lesions.
|Tissue Biopsy and Surgery
||Methods that sample small pieces of tissue (biopsy) from a particular site, often via endoscopic techniques (such as colonoscopy, upper endoscopy, or bronchoscopy) can often yield a specific diagnosis of malignancy. At surgery, portions of an organ or tissue can be sampled, or the diseased tissue(s) removed and examined in surgical pathology to determine the stage and grade of the neoplasm.
||Sometimes neoplasms are not detected or completely diagnosed during life. The autopsy serves as a means of quality assurance for clinical diagnostic methods, as a way of confirming diagnoses helpful in establishing risks for family members, as a means for gathering statistics for decision making about how to approach diagnosis and treatment of neoplasms, and to provide material for future research.