Tissue Sampling Techniques - Small Biopsies & Triaging

Tissue Sampling Techniques - Small Biopsies & Triaging

Most Important Steps

• Patient identification - Identification on the requisition must match the container(s). This includes name. Accession number must match requisition, specimen container and cassette.

Receiving/Accepting Specimens

• If you accept a specimen in the receiving area with incorrect information, it becomes the laboratories problem to get it back to the sender for correction. Better to refuse the specimen at the time of delivery.

• Never process a specimen without a patient name. Never label the container yourself with patient name or specimen source/type.

GROSS BENCH RULES

• Never have more than one specimen out at a time.

• Close containers when leaving the area.

• Don’t leave small biopsies on the cutting board or on paper towels.

• Keep cutting area neat, clean and organized.

• Keep sharps in clear view, not under toweling etc. Clear cutting area of sharps when leaving, and disinfect the cutting board and countertop.

• Beware of “carry-over” from case to case

Specimens can be subclassified

Depending on utility

Diagnostics specimen

Routines – Small and Large

Dermatology

Resections

Others

Depending on Nature of handling:

·         Specimens only requiring transfer from container to tissue cassette.

o   All small biopsies

o   Bone marrow & Aspirates.

o   Punch biopsies.

o   Needle biopsies

o   Any biopsies not requiring dissection

·         Specimens requiring transfer, but with standard sampling, counting, weighing or slicing.

o   Sebaceous cysts.

o   Small lipomas.

o   Unremarkable tonsils.

o   Unremarkable nasal polyps.

o   Temporal arteries.

o   Thyroglossal cysts.

o   Lymph nodes.

·         Simple dissection required with sampling needing a low level of diagnostic assessment and/or preparation.

o   Salivary gland – non-tumour.

o   Cone biopsy.

o   Small soft tissue tumours.

o   Skin biopsies – benign – requiring dissection.

o   Simple small benign biopsies.

·         Dissection and sampling required needing a moderate level of assessment.

o   Salivary gland – tumours.

o   Pigmented skin lesions.

o   Complex (non-neoplastic) gastrointestinal resections.

·         Specimens requiring complex dissection and sampling methods.

o   Bone tumours.

o   Neck dissection.

o   Mandibulectomy.

Diagnostic

• Diagnostic Cases: Small tissues being submitted to establish a diagnosis or monitor status.

Typical features of biopsy tissues;

Small in size (minute to ~1cm)

Do not require orientation

Require counting when possible

Often are submitted in “toto”

Currettings

Currettage specimens come as multiple tissue fragments admixed with; Blood or Blood Clot /Mucous

Sample EMC dictation - “Specimen consists of multiple fragments of pink/tan irregular soft tissue admixed with mucous and blood having aggregate dimensions of _____ x ______ x _____cm which are submitted in toto in a single cassette, levels are requested.

·         Small specimens should never be forcibly squeezed between the ends of a forceps or the tips of the fingers. Instead, small specimens should be gently lifted from the specimen container using the end of a wooden applicator stick or pickups. Alternatively, small specimens can be filtered directly into a tissue bag, avoiding instrumentation altogether.

·         Small specimens should be quickly placed in fixative. Ideally, most small specimens (i.e., less than 1 cm) should reach the surgical pathology laboratory already in fixative.

·         This requires that physician offices, biopsy suites, and operating rooms be supplied with appropriate fixatives, and that all personnel involved be instructed as to their proper use. Sometimes delays in fixation are necessary, as when a frozen section is required or when special tissue processing is indicated. In these instances, the tissue should be kept damp in  saline-soaked gauze.

·         Never leave small tissue fragments exposed to the air on the cutting table, and never place these small fragments directly on a dry paper towel. These practices are sure to hasten tissue desiccation.

·         For extremely small specimens, the journey from specimen container to histologic slide is a treacherous one, and they may be lost at any point along the way. For this reason, it is a wise practice to identify these small tissue fragments first and then mark the fragments so that they can be found more easily by the histotechnologist.

·         Before the specimen container is even opened, check its contents for the size and number of tissue fragments, and record these in the gross description.

·         If no tissue is seen or if inconsistencies with the requisition form are noted, carefully open the specimen container and thoroughly examine its surfaces (including the undersurface of the lid) for adherent tissue fragments. If no tissue is found or if discrepancies persist, the submitting physician should be notified immediately, and the outcome of this investigation should be documented in the surgical pathology report.

·         Once all of the tissue is identified in the specimen container, efforts should be taken to ensure that it safely reaches the histology laboratory and that it is easily identified for embedding and sectioning. Minute tissue fragments should be wrapped in porous paper or layered between porous foam pads before they are placed in the tissue cassette.

·         Before these fragments are submitted  to the histology laboratory, they can be marked with eosin or mercurochrome so that they are easier for the histotechnologist to see.