Chapter 70 Several biopsy techniques are available and the decision to use one over the others depends on specific details of the individual tumor and patient. These techniques, including incisional (needle-core, punch, wedge) and excisional biopsy, are addressed in Web Chapter 32. Specimens obtained endoscopically and via flushes or washes (e.g., nasal flush, traumatic catheterization) are also included. Principles to follow to increase the potential for obtaining a viable and representative sample by incisional biopsy include the following (Box 70-1): • Biopsy both mass and surrounding normal tissue—the tumor-nontumor junction. This region provides the highest diagnostic yield and in addition may provide information on invasion. • Avoid obtaining tissue solely from the center of the mass. The center typically is the most necrotic, which often results in a nondiagnostic sample. • Obtain ample tissue or, if possible, multiple samples from different areas. This increases the chance of obtaining a representative section. • Biopsy an alternative area of the mass if the first specimen has the following characteristics: • It is poorly structured and appears mucinous, gelatinous, semisolid, or liquefied. This may reflect poor cellularity, inflammation or abscessation, or necrosis, and may be nondiagnostic. • It is red to dark red or black and the mass is not suspected to be a melanoma. Such coloration may indicate areas of tumor-associated hemorrhage, and the specimen may be nondiagnostic. Regardless of biopsy technique, minimizing tissue artifact during and after the procedure is critical. Principles to follow include the following (Box 70-2): • Avoid excessive tissue trauma. For example, be aware of the negative effect of suction on biopsy quality, avoid crush artifact by gentle handling with forceps, and minimize the degree of palpation before biopsy or physical handling of the specimen afterward. • Electrocautery or lasers should be not be used to cut the tissue because these compromise tissue architecture, which hinders evaluation of margins and excisional completeness. After excision with a scalpel blade, electrocautery can be used for hemostasis as long as no tissue from the tumor bed will be collected. • Ensure proper fixation to preserve tissue architecture. • Specimens should be placed in 10% neutral buffered formalin, or other appropriate fixative, at a 1 : 10 tissue : formalin volumetric ratio. This should be done immediately following excision unless the specimen requires tissue marking (inking or suture placement to denote surgical margins, orientation, areas of concern, or other features). • To aid fixation of larger specimens and prevent ex vivo autolysis, make parallel incisions approximately 1.0 cm apart (“bread loafing”) if required. Incisions should not entirely transect the specimen nor should they compromise a surgical margin. Additional options for handling larger specimens are addressed later. • Avoid tissue freezing. Freezing causes ex vivo ice crystal formation, cell shrinkage, and lysis leading to extensive tissue artifact, which markedly compromises microscopic evaluation. • Never place specimens in a freezer. Refrigeration is acceptable. • Never ship specimens on dry ice. Ice packs and other cooling inserts are acceptable if needed. • To avoid freezing during shipment in cold environments, pack the specimen in an insulated container or add isopropyl alcohol to the formalin fixative (1 part alcohol to 10 parts formalin). Tissue specimens range from endoscopic biopsy samples to entire spleens and amputated limbs. There is no one way to handle all specimens, although the principles listed earlier universally apply. This section addresses methods of handling some unconventional biopsy specimens. Methods and principles of tissue marking (e.g., identifying surgical margins) as well as the benefits of providing thorough information on the submission form also are addressed. Further information on these topics is available in a recent consensus document (Kamstock et al, 2011), which readers are encouraged to review. • The container should be a wide-mouthed plastic jar with a lid that seals securely. • If the jar has a narrow neck, the neck must be wider than the specimen being submitted. Fresh tissue is malleable and can be squeezed through the neck easily; however, fixed tissue becomes rigid and will be impossible to retrieve without damage. • The container (not lid) should be labeled with the patient’s name, case number, and anatomic site from which the specimen was obtained (e.g., dermal mass, thorax). If multiple specimens are submitted in one jar, a numbered list of the specimens and respective anatomic sites should be provided and the specimens themselves should be identified so that they correlate with the list. • The container should be placed in one, if not two, secured and sealed plastic bags to contain any leakage during shipping and should be surrounded by absorbent packing material. • Glass should be avoided because it carries a greater risk of breaking in transit.
Tumor Biopsy and Specimen Submission
Tumor Biopsy and Tissue Procurement
Obtaining a Diagnostic Sample
Minimizing Tissue Artifact: Handling and Fixation
Sample Submission
Fixation and Packaging
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Tumor Biopsy and Specimen Submission
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