Cytologic, Histologic, and Genetic Studies

Cytologic, Histologic, and Genetic Studies


Cytologic Studies

Exfoliated cells in body tissues and fluid are studied to determine the types of cells present and to diagnose malignant and premalignant conditions. The staining technique developed by Dr. George N. Papanicolaou has been especially useful in diagnosis of malignancy and is now used routinely in the cytologic study of the female genital tract as well as in many types of nongynecologic specimens.

Some cytologic (cells) specimens (e.g., smears of the mouth, genital tract, nipple discharge) are relatively easy to obtain for study. Other samples (e.g., amniotic fluid, pleural effusions, cerebrospinal fluid [CSF]) are from less accessible sources, and special techniques, such as fine-needle aspiration, are required for collection. Tissue (histologic) samples may be obtained by biopsy during surgery or during outpatient diagnostic procedures such as endoscopy. In all studies, the source of the sample and its method of collection must be noted so that the evaluation can be based on complete information.

Specimens for cytologic and histologic study usually consist of many different cells. Some are normally present, whereas others indicate pathologic conditions. Cells normally observed in one sample may, under certain conditions, be indicative of an abnormal state when observed elsewhere. All specimens are examined for the number of cells, cell distribution, surface modifications, size, shape, appearance and staining properties, functional adaptations, and inclusions. The cell nucleus is also examined. Any increases or decreases from normal values are noted.

Gynecologic specimens may be smeared and fixed in 95% alcohol. Some types of spray fixative are also available. (Gynecologic specimens collected using the liquid-based technique are collected in special [e.g., PreservCyt] solution.) Nongynecologic specimens are generally collected without preservative. They may be placed in saline, and they must be handled carefully to prevent drying or degeneration. Check with your individual laboratory for collection requirements. It is important that all cytology specimens be sent to the laboratory as soon as they are obtained to prevent disintegration of cells or any other process that could cause alteration of the material for study (Table 11.1).

In practice, results of cytologic studies are commonly reported as:

  • Inflammatory

  • Benign

  • Atypical

  • Suspicious for malignancy

  • Positive for malignancy (in situ versus invasive)

TABLE 11.1 Nucleic Acid Testing Performed in Gynecologic Cytology




Human papillomavirus low and high risk

Liquid-based Pap; PreservCYT

Hybrid Capture II (Digene)

Chlamydia trachomatis

Liquid-based Pap; PreservCYT

Cervical cytology plus Hybrid Capture II

Neisseria gonorrhoeae

Liquid-based Pap; PreservCYT

Polymerase chain reaction

Herpes simplex virus types 1 and 2

Liquid-based Pap; PreservCYT

Polymerase chain reaction

Modified from Bentz JS: Molecular testing in cytopathology: Where are we, where do we go from here? Northfield, IL, CAP Today, College of American Pathologists, 20:2, 2006.

Histologic Studies

Material submitted for tissue examination may be classified according to its histologic or cellular characteristics. A basic method for classifying cancers according to the histologic or cellular characteristics of the tumor is Broders’ classification of malignancy:

  • Grade I: tumors showing a marked tendency to differentiate; 75% or more of cells differentiated

  • Grade II: 75% to 50% of cells differentiated, slight to moderate dysplasia and metaplasia

  • Grade III: 50% to 25% of cells differentiated, marked dysplasia, marked atypical features, and cancer in situ

  • Grade IV: 25% to 0% of cells differentiated

The tumor-node-metastasis (TNM) system is a method of identifying tumor stage according to spread of the disease. This system evolved from the work of the International Union Against Cancer and the American Joint Committee on Cancer. In addition, the TNM system further defines each specific type of cancer (e.g., breast, head, neck). This staging system is employed for previously untreated and treated cancers and classifies the primary site of cancer and its extent and involvement, such as lymphatic and venous invasion.


Fine-Needle Aspirates: Cell (Cytologic) and Tissue (Histologic) Study

Fine-needle aspiration is a method of obtaining diagnostic material for cytologic (cell) and histologic (tissue) study that causes a minimal amount of trauma to the patient. Aspirates may be obtained from all parts of the body, including the mouth, breast, liver, genital tract, respiratory tract, urine, cerebrospinal fluid, and thyroid. Bacteriologic studies may also be done on material obtained during fine-needle aspiration. Unfixed material, left in the syringe or on a needle rinsed in sterile saline, may be taken to the microbiology department for study.

Reference Values


Benign or negative: no abnormal cells or abnormal tissue present

No pathogenic organisms

Sentinel Node Location Before Biopsy (Breast, Melanoma); Special Prebiopsy Study

The concept of identifying and localizing the sentinel node or nodes before biopsy is that these nodes receive initial lymphatic drainage and are the first filter to remove metastatic cells; thus, if this sentinel
node is free of disease, the rest of the nodes in the patient will also be free of disease. Three methods (along with marking of the skin) are used: (1) lymphoscintigraphy (preoperative), (2) nuclear probe localization (intraoperative), and (3) blue dye injection (intraoperative). Often, all three techniques are used together, the lymph nuclear scan being the most common (see Procedures).

These special prebiopsy procedures are done before biopsies to diagnose cancer of breast or melanoma. Indications for lymph nuclear scan lymphoscintigraphy include detection of metastasis, mapping of all sentinel nodes, and staging and monitoring cancers, such as melanoma, breast, head, neck, and skin. Indications for using the nuclear gamma-radiation probe include detecting the most sentinel nodes and providing auditory confirmation. See Chapter 9 for more information on nuclear scans. Indications for blue dye staining include to provide visual confirmation of nodes and to map tumor route (urine will turn blue and skin will stain).

Reference Values


No evidence of tumor activity

No blocked lymphatic drainage

Tissue (Histologic) Biopsy Studies: Overview; Prognostic and Predictive Markers

Tissue biopsies from many body sites (e.g., breast, liver, kidney, lymph nodes, skin, bone, muscle, lung, bladder, prostate, thyroid, cervix) may be examined for the presence of benign, toxic, or malignant cells and conditions. The amount of tissue obtained and submitted to the laboratory depends on the specimen site and disease process (e.g., in liver biopsy, at least two to three liver cores >2 cm in length). These procedures may be performed in outpatient or inpatient settings. Some specimens should be collected early in the day. For ultrasound-guided prostate specimens (i.e., transrectal ultrasound [TRUS]), 6 to 12 threadlike sections of tissue are obtained, ranging from 0.5 to 1.5 cm in length. Pain and bloody urine are common afterward. Depending on the body site sampled, anesthetic (i.e., local or general) or conscious sedation and analgesia may be indicated.

Tissue obtained for routine histologic (tissue study) and pathologic examination requires special handling (e.g., place in 10% formalin or send fresh and intact). Tissue needed for frozen-section examination must be delivered to the laboratory immediately with no fixative added. Tissue needed for special studies (e.g., special stains for microorganisms, hormonal studies, DNA ploidy, bone biopsies) may need special handling. A frozen section is done upon the pathologist’s recommendation. Tissue freezing (frozen section) may actually be contraindicated and not in the patient’s best interest. Contact your individual laboratory for specific instructions.

After the biopsy specimen is sent to the laboratory, various tests are done to identify the unique characteristics of the patient’s tumor cells and to select correct chemotherapy based on resistance to specific drugs. Multiple and complex genetic changes result from loss of control over normal cell growth, and these alterations may influence the tumor’s response to chemotherapy. To measure these changes, four major testing groups are used and include the following:

  • Extreme drug resistance (EDR) assay tests of solid tumors and malignant fluids (blood, bone marrow effusions), which determine the probability of a tumor’s resistance to specific chemotherapeutic drugs (e.g., 5-fluorouracil [5-FU] for colon cancer). If the tumor cells grow in the presence of extreme exposures to a specific drug, this indicates the presence of significant drug resistance and, by identifying inactive agents, avoids exposing patients to the toxicity of drugs that are likely to be ineffective, saves valuable treatment time, and decreases the possibility of cross-resistance to other effective agents.

  • Differential staining and cytotoxicity (DiSC) assay uses special stains and techniques to detect drug resistance in leukemia, lymphoma, blood, and bone marrow specimens.

  • Prognostic markers measure the tumor’s growth potential or ability to invade other tissues (metastasis). Tumor cells release proteases and angiogenic factors to break down basement membranes and induce new vascularization of the tumor, which delivers oxygen and nutrients to the tumor and allows micrometastasis to distant sites.

  • Predictive markers identify specific mechanisms of drug resistance and provide information on how effective clinically indicated chemotherapy agents will be in treating the patient’s tumor cells. Prognostic and predictive markers use molecular probes to determine the genetic characteristics, amount of protein, proliferation index, resistance mechanisms, receptor status, and other defining factors of the patient’s malignant tumor. To obtain the most comprehensive analysis of the patient’s unique tumor biology, drug resistance testing is done in combination with oncoprofiles and prognostic and predictive markers for the specific cancer type. A radiation resistance assay can also be done before the treatment actually begins.

These combined studies identify cervical cancer resistive to internal and external radiation plus chemotherapy (the standard treatment is prognostic indicators of progression-free survival). Also included are p53, thrombospondin-1 (Tsp-1), CD31, and angiogenesis index (AI). Prognostic and predictive markers are as follows:

  • Androgen receptor. This receptor predicts prostate cancer’s response to hormone therapy.

  • Angiogenesis index (p53, Tsp-1, CD31). The AI defines a patient’s risk for occult metastatic disease and is composed of factors that characterize the capacity for new blood vessel formation: p53, Tsp-1, and CD31 (vessel count). The p53 gene contributes to tumor growth suppression by slowing cell cycle progression and promoting apoptosis in damaged tumor cells. It also suppresses tumor angiogenesis. Tsp-1 levels have been found to decrease after the tumor sustains mutations in p53. CD31 is expressed on the membrane of endothelial cells, allowing for microvessel count in the tumor.

  • BAX. Increased levels of BAX, a 21-kd protein and amino acid, indicate accelerated programmed cell death induced by apoptotic stimulus.

  • Proto-oncoprotein bcl2 (apoptosis regulator). The translocation of the bcl2 gene, occurring in follicular lymphomas, is brought under control of the immunoglobulin gene promoter, resulting in increased intracellular levels of bcl2 protein. This protein suppresses programmed cell death (apoptosis). Induction of cell death is an important mechanism for many chemotherapeutic agents. An abnormal expression of bcl2 protein can render tumor cells resistant to chemotherapeutic agents.

  • Cathepsin D (invasion potential). Cathepsin D, a lysosomal acid protease, has been associated with metastatic potential. Elevated levels of cathepsin D are predictors of early recurrence and death in node-negative cancer and breast cancer.

  • CD31 (component of tumor angiogenesis index). CD31 stains microvessels, allowing for counting, and helps to predict more aggressive disease, metastases, poor survival, and new vascularization of the tumor mass.

  • DNA ploidy and S phase (flow cytometry). DNA ploidy and proliferative index are independent indicators of prognosis. Patients with aneuploid tumors or high S-phase fractions have poor disease-free survival compared with patients with diploid or low S-phase fraction tumors. DNA ploidy (image analysis) (Feulgen stain) is an indicator of prognosis in selected tumor types in fresh specimens.

  • Epidermal growth factor receptor (EGF-R). This growth factor receptor is a glycoprotein tyrosine kinase, either EGF or transforming growth factor-α (TGF-α). When high levels occur in breast, prostate, ovarian, lung, and squamous cell carcinomas, there is an association with poorer prognosis and poor disease-free survival.

  • Endoglin (CD105). Endoglin normally occurs in vascular endothelial cells of capillaries, arterioles, small arteries, and venules. Increased levels are found in tumor vessels and proliferating endothelial cells. Endoglin has been found in non-T/non-B and pre-B acute lymphoblastic leukemia (ALL) and acute myelocytic and myelomonocytic leukemia cells.

  • Estrogen receptor (ER) and progesterone receptor (PR). ER and PR positivity is associated with a 70% response rate to antihormonal therapy. In contrast, the response rate is less than 10% among
    patients whose tumors are ER and PR negative. Patients whose tumors are ER and PR positive generally achieve superior disease-free survival.

  • Glutathione S-transferase (GST); alkylator resistance. GST is an enzyme that inactivates certain anticancer agents by linking glutathione to the drug. Increased GST levels are associated with tumor resistance to chlorambucil and melphalan.

  • HER2/neu c-erbB2 oncoproteins. The presence of HER2/neu, a protein that functions as an oncogene, is associated with poorer prognosis. HER2/neu detection also provides information on the potential treatment response to trastuzumab (Herceptin).

  • Ki-67 (proliferative index). This is a staining technique. Monoclonal antibody Ki-67 is associated with increased cell proliferative activity in tumors and with more aggressive tumors and poor disease-free survival.

  • MDR-1 (P170 glycoprotein: multidrug resistance). The presence of MDR-1 cancer cells is associated with resistance to naturally produced chemotherapeutic agents such as paclitaxel (Taxol), doxorubicin, and etoposide and plays a critical role in the selection of a treatment regimen.

  • O6-methylguanine-DNA methyltransferase (MGMT) (nitrosourea resistance). MGMT, a repair protein, occurs after DNA damage caused by nitrosoureas, such as BCNU. Brain cancer patients with high levels of the MGMT gene and alkyltransferase (AT) have shorter disease-free and overall survival.

  • Multidrug resistance protein (MRP). This protein is similar to, but distinct from, MDR-1 and is strongly associated with resistance to cisplatin drugs in ovarian cancer.

  • p21. A protein-like tumor suppressor like p53, p21 controls when and how the cell replicates. Low levels of p21 are associated with increased risk for tumor occurrence, and the absence of p21 contributes to aggressive growth in some tumors.

  • p53 (cell cycle and Tsp-1 regulator). The tumor suppressor gene p53 regulates cell cycle progression, cellular proliferation, DNA repair, apoptosis (cell death), and angiogenesis. Increased levels of mutated p53 protein in tumor cell nuclei are associated with tumor progression and a poorer prognosis.

  • PCNA (proliferative index). Presence of PCNA protein is associated with cell proliferation, and increased levels occur with more aggressive tumors and are associated with poor disease-free survival.

  • Thymidylate synthase (TS; 5-FU resistance). Drug resistance tests of thymidylate synthase (TS), a cellular enzyme essential for DNA biosynthesis and cell proliferation that is a target for 5-FU, is an important component of some breast cancer and colon cancer treatment regimens. Increased TS expression correlates with poorer response rates to 5-FU and with shorter survival in breast and colon cancer.

  • Thrombospondin-1 (Tsp-1). This extracellular matrix protein is involved in wound healing. Low value is associated with increased tumor neovascularity and mutant p53 expression.

  • UIC-2 (MDR-1) shift assay. This staining technique can be performed on solid tumors. The UIC-2 shift assay can be performed on blood and bone marrow specimens from patients with acute myelogenous leukemia (AML), multiple myeloma, or lymphoma and, if the sample contains an adequate amount of viable tumor cells, on solid tumors.

  • Vascular endothelial growth factor (VEGF). Vascular endothelial growth factor, or vascular permeability factor (VPF), plays an important role in angiogenesis, which promotes tumor progression and metastasis.

Oncoprofiles provide the maximum useful information from a single biopsy specimen. These diseasespecific marker studies include tests that have been associated with clinical outcomes for each cancer type. Oncoprofiles identify relative risk for relapse and assist in planning therapy for each patient’s specific tumor. Table 11.2 shows an example of oncoprofiles offered by Oncotech, Inc., of Irvine, California.

TABLE 11.2 Useful Information From a Single Biopsy Specimen*


Basic Profile

Comprehensive Profile

Bladder cancer

DNA, p53, HER2/neu

DNA, p53, HER2/neu, CD31

Brain cancer

DNA, p53, HER2/neu

DNA, p53, HER2/neu, CD31

Breast cancer

DNA, ER/PR, HER2/neu

DNA, ER/PR, HER2/neu, p53, CD31

Colon cancer

DNA, p53

DNA, p53, TS, MDR-1, CD31

Endometrial cancer

DNA, ER/PR, Ki-67

DNA, ER/PR, Ki-67, CD31, MDR-1, p53

Kidney cancer


DNA, MDR-1, p53, CD31

Leukemia/non-Hodgkin’s lymphoma

DNA, Ki-67

DNA, Ki-67, bc12, p53, MDR-1

Lung cancer

DNA, p53

DNA, p53, MDR-1, bc12



DNA, MDR-1, p53, CD31

Ovarian cancer


DNA, ER/PR, HER2/neu, EGF-R, p53, MDR-1

Prostate cancer


DNA, AR, p53, CD31


DNA, p53

DNA, p53, MDR-1

Unknown primary site

DNA, p53, HER2/neu

DNA, p53, HER2/neu, MDR-1

*The laboratory report from these tumor studies should provide answers to questions such as “Is the tumor malignant?”, “Is type of cancer identified?”, “How aggressive is the cancer?”, “Is the cancer likely to recur?”, and “To which drugs is the tumor resistant?”

Posttest Patient Care

  • Monitor for signs of bleeding, inflammation, infection, laceration of tissue and organs, and perforation. Treat pain, which may be experienced to various degrees depending on the body site sampled.

  • Counsel the patient about follow-up procedures and treatment for infections and malignant conditions.

  • Follow the guidelines in Chapter 1 for safe, effective, and informed posttest care.

Breast Biopsy: Cell (Cytologic) and Tissue (Histologic) Study and Prognostic Markers

Breast biopsies are among the most common type of biopsy done. The cells and tissue obtained by breast biopsy establish the presence of breast disease, diagnose histopathology, and classify the process. They also confirm and characterize calcifications noted in prebiopsy mammograms. The breast tissue is examined to determine surgical margins, presence or absence of vesicular invasion, tumor type, staging, and grading. Secondary studies relevant to survival may include imaging procedures, along with the following prognostic markers. (Also see Tumor Markers in Chapter 8 for more information.)

  • ER and PR. These hormone receptors are indicators of prognosis and are used to manage hormonal therapy in breast and endometrial cancer. Immunohistochemical (IHC) staining aids recognition of metastatic breast cancer.

  • DNA ploidy. This test measures cell turnover or replication; it is used to predict prognosis and shorter survival times by the presence of aneuploid (rapidly replicating cells) for certain tumor types, such as breast, prostate, and colon; it is less clear for ovarian, lung, kidney, and bladder (urine) tumors (66% of breast cancers are aneuploid).

  • S-phase fraction (SPF)—to predict survival and reduced chance of relapse. Low levels of SPF appear to have longer survival and reduced chance of relapse. SPF is the DNA synthesis phase obtained by a statistical method.

  • Cathepsin D—done to determine prognosis. The presence of this lysosomal protease is estrogen related and may promote tumor spread. Prognostic significance remains ambiguous.

  • EGF reception—done to predict survival time. Presence is correlated with ER negativity, aneuploidy, increased S-phase factors, and lymph node metastases. Increased EGF reception may be associated with worse relapse free and survival time.

  • p53 Gene—used to predict prognosis. This tumor suppressor gene regulates cell cycles. Some clinicians believe that the prognostic value of the p53 gene is second only to lymph node status.

  • c-erbB2 (HER2) oncogene—determines which patients are most likely to benefit from high doses of chemotherapy. High levels of this oncogene receptor are associated with poor response to conventional chemotherapy and may be a marker for patients likely to benefit from high doses of chemotherapy. HER2/neu levels may also be determined in a blood specimen.

Gene profiling technologies have also allowed identification of different types of breast cancer, such as Luminal A and Luminal B (hormone-receptor positive tumors that arise from luminal cells), HER2 (hormone-receptor negative tumors), BRCA (tumors due to gene mutations), and basal (negative for progesterone and estrogen receptors).

Reference Values


Negative for malignant or other abnormal cells and tissue

Prognostic markers: of no significance or negative

No vascular invasion

DNA index: 0.8-1.2 on the diploid scale

Proliferative antigen index of 10% S phase: 7% = amount of cells on the S phase

Ductal Lavage of Breast Cells (Cytologic) Study; Gail Index of Breast Cancer Risk

Ductal lavage collects cells from the milk ducts of the nipple, where most breast cancers begin. If cytologic study shows abnormal cells, this is an indication of increased risk for breast cancer development. Ductal lavage is used to assess breast cancer risk and for ongoing surveillance. A statistical model
computes a Gail Index Score in a woman of a given age and with the presence of certain factors that indicate risk for developing breast cancer over a specified interval. The Gail Index Score is based on risk factors (e,g., late age at menarche, late age at first live birth, number of previous biopsies, and number of first-degree relatives with breast cancer).

Reference Values


No atypical or abnormal cells

Gail Index of breast cancer risk = odds ratio ≤ 1.7. For more information, see Gail et al., 1989.

Liver Biopsy: Cell (Cytologic) and Tissue (Histologic) Study

Liver needle biopsy is an invasive procedure and is done to confirm diagnosis of chronic hepatitis and liver cirrhosis, evaluate disease severity, and establish etiology. Cellular material from the liver may be useful in evaluating the status of the liver in diffuse disorders of the parenchyma and in the diagnosis of space-occupying lesions. Liver biopsy is especially useful when the clinical findings and laboratory test results are not diagnostic (e.g., an aspartate aminotransferase [AST] level 10 to 20 times less than the upper defined limit with an alkaline phosphatase [ALP] level less than 3 times the limit) and when the diagnosis or cause cannot be established by other means (enlarged liver of unknown cause or systemic disease affecting the liver, such as miliary tuberculosis). Other indications for liver biopsy include evaluation of chronic hepatitis, portal hypertension, and fever of unknown origin (tuberculosis and brucellosis) and to confirm alcoholic liver disease.

Reference Values


Negative for malignant or other abnormal cells and abnormal tissue

No evidence of local or diffuse liver disease

No evidence of toxic reaction to drugs or inflammatory reactions

No pathogenic organisms present

Interfering Factors

The reported effectiveness of liver aspirates or biopsies varies in the limited published information. Because a very small fragment of tissue, often partially destroyed, is taken in a random manner from a large organ, localized disease is easily missed.

  • False-negative results may be caused by:

    • Sampling error. Detection rate of liver metastases is approximately 50% to 70% with blind biopsy and about 85% (range, 67% to 96%) with the use of ultrasound guidance. Also, many diseases produce nonspecific changes that may be spotty, healing, or minimal.

    • Degeneration or distortion caused by faulty preparation of specimen.

  • False-positive results may be caused by misinterpretation of markedly reactive hepatocytes.

Kidney Biopsy: Cell (Cytologic) and Tissue (Histologic) Study

Kidney biopsy is used to establish a diagnosis in the presence of renal dysfunction, evaluate severity and extent of disease, guide therapy, and identify candidates for kidney transplantation.

Reference Values


No patterns of abnormality or abnormal glomeruli

No evidence of drug toxicity, infection, or inflammation

Respiratory Tract: Cell (Cytologic) and Tissue (Histologic) Study

The lungs and the passages that conduct air to and from the lungs form the respiratory tract, which is divided into the upper and lower respiratory tracts. The upper respiratory tract consists of the nasal cavities, the nasopharynx, and the larynx; the lower respiratory tract consists of the trachea and the lungs.

Sputum is composed of mucus and cells. It is the secretion of the bronchi, lungs, and trachea and is therefore obtained from the lower respiratory tract (bronchi and lungs). Sputum is ejected through the mouth but originates in the lower respiratory tract. Saliva produced by the salivary glands in the mouth is not sputum. A specimen can be correctly identified as sputum in microscopic examination by the presence of dust cells (carbon dust-laden macrophages). Although the glands and secretory cells in the mucous lining of the lower respiratory tract produce up to 100 mL of fluid daily, the healthy person normally does not cough up sputum.

Cytologic studies of sputum and bronchial specimens are important as diagnostic aids because of the frequency of cancer of the lung and the relative inaccessibility of this organ. Also detectable are cell changes that may be related to the future development of malignant conditions and to inflammatory conditions.

Reference Values


Negative for abnormal cells or tissue

No pathogenic organisms

Interfering Factors

  • False-negative results may be caused by:

    • Delays in preparation of the specimen, causing a deterioration of tumor cells

    • Sampling error (Diagnostic cells may not have exfoliated into the material examined.)

  • The frequency of false-negative results is about 15%, in contrast to about 1% in studies for cervical cancer. This high incidence occurs even with careful examination of multiple deep cough specimens.

Selection of Medications and Media for All Respiratory Cell and Tissue Procedures

  • Mild sedative and analgesia and/or local anesthetic may be used during bronchoscopy. Analgesia is indicated for pain after bronchoscopy. See Chapter 12 for bronchoscopy care.

  • Sputum specimens are collected in a wide-mouthed container; 50% alcohol may be added if transportation to the laboratory will be delayed.

  • Bronchial washings may be collected in a trap tube or wide-mouthed container.

  • Bronchial brushes may be smeared directly on glass slides, which are then fixed immediately in 95% alcohol or spray fixative. Brushes may be placed in a fixative solution such as 50% alcohol.

Gastrointestinal Tract: Cell (Cytologic) and Tissue (Histologic) Study

Exfoliative cytology of the gastrointestinal tract is useful in the diagnosis of benign and malignant diseases. It is not, however, a specific test for these diseases. Many benign diseases, such as leukoplakia of the esophagus, esophagitis, gastritis, pernicious anemia, and granulomatous diseases, may be recognized because of their characteristic cellular changes. Response to radiation may also be noted from cytologic studies.

Reference Values


Negative for abnormal cells

Squamous epithelial cells of the esophagus may be present.

Interfering Factors

The barium and lubricant used in Levin tubes interfere with good results because they distort the cells and prevent accurate evaluation.

Papanicolaou (Pap) Smear: Cell (Cytologic) Study of the Female Genital Tract, Vulva, Vagina, and Cervix; DNA Test for Human Papillomavirus (HPV)

Characteristic physiologic cellular changes occur in the genital tract from birth through the postmenopausal years. Three major cell types occur in a characteristic pattern in normal vaginal smears:

  • Superficial squamous cells (mature squamous, usually polygonal, containing a pyknotic [thick, compact, dense] nucleus)

  • Intermediate squamous cells (mature squamous, usually polygonal, containing a clearly structured vesicular nucleus, which may be either well preserved or changed as a result of bacterial cytolysis)

  • Parabasal cells (immature squamous, usually round or oval, containing one or, rarely, more than one) as a result of degeneration or necrosis

Findings indicate that presence of human papillomavirus (HPV) may be associated with the development of cervical cancer.

The Papanicolaou (Pap) cytologic smear is used principally for early detection of cervical cancer and diagnosis of precancerous and cancerous conditions of the vulva and vagina. In the United States, 50 million Pap smears are performed annually. The U.S. Preventive Services Task Force recommends conventional Pap tests every 3 years for women ages 21-65. Women ages 30-65 may choose co-testing (Pap test plus HPV testing) every 5 years. After age 65 years with prior normal tests, she may choose to stop cervical screening (Table 11.3). This test is also used for diagnosis of inflammatory and infectious diseases. HPV testing is recommended for all women with a Pap cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS).

The value of the Pap smear depends on the fact that cells readily exfoliate (or can be easily stripped) from genital cancers. Cytologic study can also be used for assessing response to administered sex hormones. The microbiologic examination on cytology samples is not as accurate as bacterial culture, but it can provide valuable information.

Specimens for cytologic examination of the genital tract are usually obtained by vaginal speculum examination or by colposcopy with biopsy. Material from the cervix, endocervix, and posterior fornix is obtained for most smears. Smears for hormonal evaluation are obtained from the vagina.

In an effort to standardize reporting of cervical-vaginal cytology specimens, the Bethesda System for reporting cervical-vaginal diagnoses was developed by a 1977 National Cancer Institute workshop and slightly modified after a second workshop in 1991 and revised in 2001. This reporting system is being adapted by numerous laboratories nationwide. The terminology of this reporting system appears in Chart 11.1

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Jun 11, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Cytologic, Histologic, and Genetic Studies

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