If the differential diagnosis includes malignancy, a tissue specimen must be obtained. Incisional biopsy is indicated in this situation so that definitive treatment of the potential malignancy is not compromised. If the differential diagnosis does not include malignancy, lesions of reasonable size in manageable locations can be completely excised at biopsy.
A variety of authors have proposed size limits for excisional biopsy. General dentists, dermatologists, oral and maxillofacial surgeons, otolaryngologists, and others undoubtedly have different comfort and skill levels; therefore, specific size guidelines for incisional biopsy versus excisional biopsy have little value. Similarly, clinicians who are uncomfortable with the regional anatomy should not perform excisional biopsy of lesions near significant anatomic structures. When excisional biopsy is being considered, the physician should also be aware that it may produce esthetic compromise as a result of scarring or residual deformity. The esthetic outcome is of particular concern when a lesion on the lip is near the vermilion border.
Numerous methods can be used to collect tissue samples from the oral mucosa for histopathologic examination. Performing biopsy with a scalpel is the standard and generally produces the most satisfactory specimen. Other techniques include the use of a needle, biopsy punch, biopsy forceps, laser, or electrocautery device. Needles may be appropriate in sampling cells from mass lesions, but they are of no benefit in the evaluation of surface lesions. Electrocautery produces thermal damage and artifact, which make evaluation of the specimen difficult; therefore, electrosurgery should be avoided during oral mucosal biopsy. Electrosurgery may be of benefit for wide local excisions of known intraoral malignancies after a scalpel is used to atraumatically obtain marginal specimens for frozen sections.
A carbon dioxide or Nd:YAG laser produces a zone of thermal coagulation smaller (approximately 500 µm) than that of electrocautery (see the image below).
Diagram illustrates thermal damage zones caused by carbon dioxide laser.
If a laser is used for incisional or excisional biopsy, a 0.5-mm margin should be maintained between the cut and the representative area to be sampled. Although this technique may result in good local hemostasis and minimal postoperative discomfort, it is associated with potential shortcomings, including impingement on the specimen, particularly at the deep margin, and the generation of excessive heat with inadequate removal of the charred layer. The laser may be of great value in managing the wound left by scalpel biopsy in areas of the mouth where closure is difficult or inappropriate.
Biopsy forceps are long-handled instruments with biting ends that are cup shaped to harvest an adequate amount of mucosa. They are particularly useful in pharyngeal lesions for which the use of a scalpel is more challenging. The specimen is not crushed in the cup and should be eminently assessable by the pathologist (see the image below).
Biopsy forceps.
The use of a biopsy punch in oral mucosal lesions is described and may be of some value. Punch biopsy may be difficult on freely movable oral tissues and probably offers no advantage compared with scalpel biopsy (see the image below). The technique may be appropriate in the hard palate and other sites with better support and tissue that is bound down, and it is likely to produce a satisfactory specimen. The wound heals by secondary intention, and discomfort may persist longer than anticipated by the clinician and the patient.
Biopsy punch.
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