BIOPSY AND CYTOLOGY
Biopsy
• Definition
• Biopsy is the removal of a sample of living tissue for laboratory examination.
• Rationale
• It is a dentist’s obligation to make a diagnosis, or see that a diagnosis is made, of any
pathological lesion in the mouth.
• Some lesions can be diagnosed clinically, and biopsy is not required e.g. recurrent
aphthous ulceration, Herpes simplex lesions.
• Many lesions cannot be positively diagnosed clinically and should be biopsied – or in
some cases smeared for cytopathologic examination.
• Pitfalls of relying on a strictly clinical diagnosis are numerous:
• A loose tooth may be due to a malignancy, not to advance periodontal disease.
• What appears to be a dentigerous cyst clinically e.g. may be an odontogenic
tumor.
• Harmless looking white patches may be malignant or premalignant. Red patches
are even more important.
• It has been said that “any tissue which has been removed surgically is worth
examining microscopically”
• Yet dentists in general do not follow this rule.
• However, there are some tissues e.g. gingivectomies, where every specimen need
not be submitted.
• While cancer is one disease in which biopsy is important, there are many other
lesions in which this procedure is useful.
• It is a sensitive diagnostic tool.
CDE (Oral Pathology and Oral Medicine) 1 BIOPSY AND CYTOLOGY
, • Methods of Biopsy
• Excisional – entire lesion is removed, along with a margin of normal tissue.
• Incisional – representative portion of the lesion is removed, along with a margin of
normal tissue.
• Electrocautery – tends to damage tissue and make interpretation difficult.
• Punch
• Needle and aspiration
• Curettage – intraosseous
• Exfoliative cytology.
• The Oral Biopsy – Avoidable Pitfalls.
• Tissue alteration before the biopsy is taken.
• Do not apply antiseptics e.g. iodine, or topical anesthetics to the surface of the
lesion. This may leave an unnecessary deposit on the tissues.
• Local anesthetic infiltrations should be injected around the periphery of the
lesion – infiltration directly into the lesion will cause volumetric distortion.
• Tissue alteration during the biopsy procedure.
• Impaction of bone dust, dentine dust and enamel fragments into some intrabony
lesions is unavoidable.
• Electrosurgery.
• Produces significant coagulation damage, particularly at margins of biopsy
specimen, and can completely ruin small biopsies.
• Can be useful to control bleeding.
• Crush, puncture and tear artifacts.
• Avoid grasping tissue with forceps, hemostats – these produce crush and tear
artefacts which make histologic interpretation difficult. Toothed forceps can
leave puncture holes which resemble cysts.
CDE (Oral Pathology and Oral Medicine) 2 BIOPSY AND CYTOLOGY
Biopsy
• Definition
• Biopsy is the removal of a sample of living tissue for laboratory examination.
• Rationale
• It is a dentist’s obligation to make a diagnosis, or see that a diagnosis is made, of any
pathological lesion in the mouth.
• Some lesions can be diagnosed clinically, and biopsy is not required e.g. recurrent
aphthous ulceration, Herpes simplex lesions.
• Many lesions cannot be positively diagnosed clinically and should be biopsied – or in
some cases smeared for cytopathologic examination.
• Pitfalls of relying on a strictly clinical diagnosis are numerous:
• A loose tooth may be due to a malignancy, not to advance periodontal disease.
• What appears to be a dentigerous cyst clinically e.g. may be an odontogenic
tumor.
• Harmless looking white patches may be malignant or premalignant. Red patches
are even more important.
• It has been said that “any tissue which has been removed surgically is worth
examining microscopically”
• Yet dentists in general do not follow this rule.
• However, there are some tissues e.g. gingivectomies, where every specimen need
not be submitted.
• While cancer is one disease in which biopsy is important, there are many other
lesions in which this procedure is useful.
• It is a sensitive diagnostic tool.
CDE (Oral Pathology and Oral Medicine) 1 BIOPSY AND CYTOLOGY
, • Methods of Biopsy
• Excisional – entire lesion is removed, along with a margin of normal tissue.
• Incisional – representative portion of the lesion is removed, along with a margin of
normal tissue.
• Electrocautery – tends to damage tissue and make interpretation difficult.
• Punch
• Needle and aspiration
• Curettage – intraosseous
• Exfoliative cytology.
• The Oral Biopsy – Avoidable Pitfalls.
• Tissue alteration before the biopsy is taken.
• Do not apply antiseptics e.g. iodine, or topical anesthetics to the surface of the
lesion. This may leave an unnecessary deposit on the tissues.
• Local anesthetic infiltrations should be injected around the periphery of the
lesion – infiltration directly into the lesion will cause volumetric distortion.
• Tissue alteration during the biopsy procedure.
• Impaction of bone dust, dentine dust and enamel fragments into some intrabony
lesions is unavoidable.
• Electrosurgery.
• Produces significant coagulation damage, particularly at margins of biopsy
specimen, and can completely ruin small biopsies.
• Can be useful to control bleeding.
• Crush, puncture and tear artifacts.
• Avoid grasping tissue with forceps, hemostats – these produce crush and tear
artefacts which make histologic interpretation difficult. Toothed forceps can
leave puncture holes which resemble cysts.
CDE (Oral Pathology and Oral Medicine) 2 BIOPSY AND CYTOLOGY
