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Cytology

Introduction

The purpose of a cytological examination is generally for the cytological detection of malignancy. Cytology laboratory offers screening of cervical-vaginal samples and the interpretation of non-gynecological and fine needle aspiration (FNA) specimens with the ultimate goal of attaining the most accurate and complete diagnosis possible.

The goals of the service include:

  • To maintain excellence in specimen preparation and diagnostic accuracy
  • To provide the highest quality consultative services to our clinical colleagues, both within our institution and elsewhere
  • To train residents, fellows, medical students and cytotechnologists in diagnostic cytopathology
  • To support and incorporate advanced diagnostic techniques to improve diagnostic accuracy

Range of Laboratory Services

Services provided by the laboratory include:

  • Gynaecological Cytology (Liquid-based Gynaecological Cytology)
  • CINTec Plus Cytology Immunocytochemistry Staining on Liquid-based Gynaecological Cytology
  • Non-Gynaecological Cytology (e.g., sputum, urines, peritoneal/ pleural fluid, BAL)
  • Fine Needle Aspiration Cytology from Various Superficial and Deep Tissues
  • Identification of infections and associated organisms including bacteria, fungi, protozoa and viruses. Special stains may be used to aid in the detection of these organisms.
  • Evaluation of joint aspirates for crystals.
  • Detection of the presence of Demodex in Eyelashes
  • Broncho-alveolar Lavage Differential Cell Count
  • Sputum Cell Count
  • ROSE (Rapid On-Site Evaluation) for specimen adequacy, at
    • Division of Vascular & Interventional Radiology (FNA/Biopsy)
      Available Monday to Friday (except PH); 8:30am to 4:30pm.
      • National Cancer Centre Singapore
        Available every Monday and Wednesday afternoon at NCCS Clinics and Monday to Friday (except PH) at NCCS Mammography suite. Booking is required. Please call 9177 8608 to schedule FNA appointment. Otherwise, please call cytology laboratory at 6576 7587 for any enquires. 
      • Diabetes and Metabolic Centre
        Available every Monday, Tuesday and Friday at Diabetes Metabolic Centre, level 3. 
      • Specialist Outpatient Clinics 
        Available Monday to Friday (except PH); 10am to 5pm.

    Other services available :

    • One-Stop Thyroid FNA Reporting
      Cases will be reported within a few hours of receipt. Please contact the laboratory for details. 
    • One-Stop Breast FNA Cytology Clinic
      Cases will be reported within a few hours of receipt. Please contact the laboratory for details.
    • FNA Procedure Performed by Pathologist
      Available Monday to Friday (except PH); 10am to 5pm, SOC Room K22.
      Booking is required. Last registration is at 4:40pm. Please call 8125 3479 to schedule an FNA appointment. Otherwise, please call cytology laboratory at 6576 7587 for any enquiries.

    Special Instructions on Specimen Collection and Handling

    • CSF and vitreous fluid degenerate within one hour, even with refrigeration. It should be collected in Shandon fixative (CSF) and Preservcyt (vitreous fluid), and sent by hand to the Cytology Laboratory as soon as possible. The Shandon fixative (pictured below) can be collected from the Cytology Laboratory.
      CSF and vitreous fluid.jpg
    • Bronchoalveolar lavages and sputum specimens that require differential cell count testing are to be transported at 4°C (on ice) and delivered within 1 hour following collection of specimen.

      Please refer to following sections for site specific collection instructions:

    (A) Gynaecological Cytology

    (B) Non-Gynaecological - Smear, Fluid and Fine Needle Aspiration (FNA)

    (C) BAL differential cell count and sputum cell count

    (D) Demodex detection in eyelashes

    (A) Gynaecological Cytology 

    The cervical (Pap) smear is a screening technique to aid in the detection of cancer and cancer precursors of the uterine cervix. It is not a diagnostic procedure. Both false-negative and rarely, false-positive results have been experienced with Pap smears. Accordingly, any lesion detected on screening should be biopsied. The Pap smear should not be used as the sole means to diagnose or exclude malignant and premalignant lesions. Cytology lab accepts liquid based (ThinPrep) and conventional pap smears. 

    1. CPOE Request

    With effect from 7 September 2016, all specimens are to be submitted with CPOE requests and labelled with their respective CPOE labels. Ordering clinicians are reminded to save the order at the end of entry to ensure proper submission of the CPOE request. Submit one request for the same patient at the same operation, irrespective of the number of specimens taken. In the event that CPOE system is not available, test request forms should be submitted. The request must include: 

    • Patient’s name, age and identification number
    • Submitting physician's name and contact number
    • Date of specimen collection
    • Source of material submitted (cervical, endocervical, vaginal, other body site)
    • Last menstrual period (LMP)
    • Hormonal status (e.g. post-menopausal, gravid)
    • Exogenous hormone therapy (including birth control pills, treatment for endocrine-responsive malignancy, estrogen creams)
    • Use of intrauterine device (IUD)
    • DES exposure
    • History of abnormal cytology and gynaecological disorders
    • History of systemic chemotherapy, pelvic radiotherapy, gynaecologic surgery, cryosurgery, electrocautery, or laser surgery
    • Any current abnormal clinical findings or patient symptoms; and
    • Risk factors for cervical cancer (e.g., multiple sexual partners, sexually transmitted diseases including human papillomavirus [HPV], sexual activity at an early age, and smoking) if obtainable. 

    It is imperative that these instructions be strictly adhered to, omission of which may result in delay of reporting.

    The following tests are available:
    1. PAP Smear (Liquid Based Cytology)
    2. Co-test: PAP Smear (Liquid Based Cytology) and HPV DNA (by Molecular Lab)
    3. PAP Smear primary with reflex HPV (Cervical Screening)
    4. HPV primary with reflex PAP Smear (Cervical Screening)
    5. PAP smear (CINtec PLUS)

    2. Patient Preparation

    • Ideal sampling date is two weeks after the first day of the LMP
    • Discourage sampling during normal menses
    • Avoid use of vaginal medication, vaginal contraceptives, or douches for 48 hours prior to examination.

    3. Collection Procedure

    Broom-Like Device Protocol - extracted from Hologic Publication

    GC Collection Proc Step 1.png
    1. Obtain an adequate sampling from the cervix using a broom-like device. Insert the central bristles of the broom into the endocervical canal deep enough to allow the shorter bristles to fully contact the ectocervix. Push gently, and rotate the broom in a clockwise direction five times.
    GC Collection Proc Step 2.png
    2.Rinse the broom as quickly as possible into the PreservCyt Solution vial by pushing the broom into the bottom of the vial 10 times, forcing the bristles apart. As a final step, swirl the broom vigorously to further release material. Discard the collection device.
    GC Collection Proc Step 3.png
    3. Tighten the cap so that the torque line on the cap passes the torque line on the vial. Label the specimen vial with the CPOE sticky label. Avoid double labelling the specimen.

    Note: Under no circumstances should the speculum be lubricated with medical jelly as it can make the Pap test unsatisfactory.

    Endocervical Brush/ Spatula Protocol - extracted from Hologic Publication

    GC EB Collection Proc Step 1.png
    1. Obtain an adequate sampling from the ectocervix using a plastic spatula.
    GC EB Collection Proc Step 2.png
    2. Rinse the spatula into the PreservCyt Solution vial by swirling the spatula vigorously in the vial 10 times. Discard the spatula.
    GC EB Collection Proc Step 3.png
    3. Obtain an adequate sampling from the endocervix using an endocervical brush device. Insert the brush into the cervix until only the bottom most fibers are exposed. Slowly rotate ¼ or ½ turn in one direction. DO NOT OVER-ROTATE.
    GC EB Collection Proc Step 4.png
    4. Rinse the brush in the same vial of PreservCyt Solution by rotating the device in the solution 10 times while pushing against the PreservCyt vial wall. Swirl the brush vigorously to further release material. Discard the brush.
    GC EB Collection Proc Step 5.png
    5. Tighten the cap so that the torque line on the cap passes the torque line on the vial. Label the specimen vial with the CPOE sticky label. Avoid double labelling the specimen.

    Note: Under no circumstances should the collection device be lubricated as it can make the Pap test unsatisfactory.

    4. Quality Indicators

    Smear Adequacy

    A satisfactory liquid-based ThinPrep preparation should show a minimum of 5,000 well-visualized/preserved squamous cells. If fewer than these are seen because of paucity of cells, poor fixation, air-drying artefact, thick smearing, or covering of blood, inflammatory exudate (with >75% of cells obscured) or other contaminants, the smear is considered unsatisfactory. A smear comprising mainly endocervical cells is also considered unsatisfactory, unless the smear was intended to specifically evaluate the endocervical canal. 

    (B) Non-Gynaecological Cytology 

    1. General Instructions

    All primary containers must be clearly labelled with at least two patient-specific identifiers, e.g. Patient’s NRIC/passport/work permit number another acceptable identifier which includes, but is not limited to: patient name or date of birth. In the case of prepared smears, all glass slides must be clearly labelled with the patient’s NRIC number and patient’s name. In the event that more than one site is aspirated, the site must be clearly indicated on each slide.
    Requests for special tests (e.g. detection of TB, fungi, crystals, immunocytochemistry, cell block preparation etc.), must be clearly indicated under the special instructions tab in the histopathology CPOE request. 

    2. CPOE Request

    With effect from 7 September 2016, all specimens are to be submitted with CPOE requests and are to be labelled with their respective CPOE labels. Submit one request for the same patient at the same procedure, irrespective of the number of specimens taken. Ordering clinicians are reminded to check the following boxes before submission:

    • Specimen label completed
    • Vetted and order form completed (Dr only)

    In the event that CPOE order is not available, hardcopy histopathological investigation request forms should be submitted. The request forms must include: 

    • Patient’s name, age, sex and identification number
    • Patient’s exact location (hospital/department/clinic/ward/bed)
    • Submitting physician’s name, MCR number and telephone number
    • Consultant-in-charge’s name and MCR number
    • Time and date of collection
    • Source of specimen/anatomic site sampled
    • The number and type of specimens submitted (containers of fluid, slides, etc.)
    • Test requested
    • Relevant clinical findings and history, including operative findings, previous laboratory accession number or date of previous operation
    • Provisional clinical diagnosis

    Specimens that require urgent reporting should be delivered immediately by hand to the cytology laboratory. The request should be indicated in the CPOE request.

    If there is an additional test (e.g.: immunocytochemistry, molecular, FISH) to be done after a case has been reported, a new CPOE request has to be submitted. The respective CPOE label has to be sent to the laboratory. The request must include:

    • Source of specimen/anatomic site sampled
    • The number and type of specimens submitted (containers of fluid, slides, etc.)
    • Test requested (under the special instructions tab)
    • Relevant clinical findings and history, including operative findings, previous laboratory accession number or date of previous operation
    • Provisional clinical diagnosis
    Failure to provide ALL the above information will delay turnaround time for the Cytology report.

    A. Fine Needle Aspiration (FNA) Smear Preparation

    1. Label all slides with patient's NRIC and name on the frosted end of the slides using a hard lead pencil prior to smear preparation.
    2. If more than one site is sampled, it is mandatory that the site of the specimen be clearly indicated on each slide and mailer.
    3. Submit a maximum of 4 slides of material (2 air-dried and 2 alcohol-fixed) from any site that can be evaluated cytologically.
    4. For alcohol-fixed slides, fix slides immediately with cytology spray fixative before air-drying occurs or immerse the slides in 95% ethanol.

    B. Fluid

    1. A maximum volume of 300mL of fluid, in an aliquot of 50 mL may be sent to the laboratory. If delay is anticipated, store the specimen at 4ºC.
    2. CSF and vitreous fluid should be collected in Shandon fixative (CSF) and Preservcyt (vitreous fluid) and sent to the laboratory immediately.
    3. Ensure that specimen bottles are tightly capped and appropriately labelled with the CPOE sticky labels.
    4. If more than one site is sampled, the source of the specimen must be indicated on each specimen container.
    5. Fluid in larger containers (e.g. 5L bottles, drip bags etc.) will NOT be accepted. 

    C. Specimen (e.g. needle rinse) sent in Formalin

    1. Specimens subjected to immunochemistry tests are to be fixed in 10% neutral phosphate-buffered formalin for at least 6hrs and up to 72hrs at room temperature.
    2. The specimen must be fully submerged with formalin to approximate specimen volume of 10:1 or higher.
    3. The type of formalin used and fixation start time should be clearly indicated in the request form.

    D. BAL and Sputum for Differential Cell Count

    1. BAL: It is recommended to submit a minimal volume of 5 mL, optimally 10 to 20 mL of a pooled BAL sample within 1 hour of collection. The specimen should be transported at 4°C (on ice) to the laboratory immediately.
    2. Ensure that specimen bottles are tightly capped and appropriately labelled with the CPOE sticky labels.
    3. If more than one site is sampled, the site of the specimen must be indicated on each specimen container. 

    E. Eyelashes for Demodex Investigation

    1. Label 2 microscope glass slides with patient's NRIC and name on the frosted end of the slides with a hard lead pencil.
    2. Place eyelashes in between the 2 microscopic slides, in the centre.
    3. Tape the short ends of the microscopic slides to ensure the eyelashes are secure.
    4. Place slide in an appropriately labelled slide container.