Oral and Maxillofacial pathology Biopsy (Principles and Techniques) A systematic approach should be developed in evaluating a patient with an oral and maxillofacial lesions, which include the following steps: 1.A detailed history 2.Clinical examination: Extraoral Intraoral 3.Special investigations: (as appropriate) Radiography or other imaging techniques Biopsy for histopathology( including immunoflourescence, immunohistochemistry, electron microscopy etc…) Specimens for microbial cultures Haematological or biochemical tests. History: 1. Demographic details (age, gender, occupation and address) 2. History of the present complaint: history of the lesion including onset, duration, time course of any changes in signs and symptoms, consider any previous treatments and their effectiveness and if there is any associated symptoms as fever, nausea or anorexia. 3. Additional questions to ask if needed: pain (if present and its character), abnormal sensation, anesthesia, dysphagia or bad taste or smell. 4. Medical history : A medical history is important as it aids the diagnosis of oral manifestations of systemic disease .It ensures that medical conditions and medication which affect dental or surgical treatment are identified. A detailed drug history is essential 5. The basic medical conditions that warrant special care include: 1-Bleeding tendencies. 2-Cardiorespiratory complaints 3-Anemias and allergies. 4-Immunocompromised patients 5-Drug treatment 1 6-Infections including(HIV/AIDS) 7-Poorly controlled diabetes mellitus 8-Likelyhood of, or exsisting pregnancy Clinical examination of the oral lesion: It should include the following when possible: inspection, palpation, percussion and auscultation Examine the physical characters of the lesion The anatomic site of the lesion The size, shape, color of the lesion The surface texture and consistency of the lesion Lymph node examination (lymphadenopathy is a common manifestation of infection but may also signify malignancy ) Imaging: The most informative imaging techniques in the head and neck are radiography, computerized tomography (CT), magnetic resonance imaging (MRI) and ultrasound. The radiographs can provide clues that will help in determining the nature of the lesion. Laboratory investigations: Oral lesions may be manifestations of systemic diseases Examples of these systemic conditions : hyperparathyroidism, paget’s disease, multiple myeloma Serum calcium, serum phosphorus, alkaline phosphatase and proteins determination can be very useful in exclusion of certain pathological conditions. Biopsy: Biopsy is the removal of a part or the whole of a lesion for the purpose of diagnostic examination. There are several types of biopsy: 2 1.Surgical biopsy: Incisional biopsy Excisional biopsy 2.Oral cytology 3.Aspiration biopsy Indications for biopsy: 1. Any lesion that persists for more than 2 weeks with no apparent etiologic basis. 2. Any inflammatory lesion that does not respond to local treatment after 10 to 14 days. 3. Persistent hyperkeratotic changes in surface tissues. 4. Any persistent tumescence, either visible or palpable beneath relatively normal tissue. 5. Inflammatory changes of unknown cause that persist for long periods. 6. Lesion that interfere with local function. 7. Bone lesions not specifically identified by clinical and radiographic findings. 8. Any lesion that has the characteristics of malignancy. Characteristics of lesions that raise the suspicion of malignancy: 1. Erythroplasia –lesion is totally red or has a speckled red appearance. 2. Ulceration-lesion is ulcerated or presents as an ulcer. 3. Duration-lesion has persisted for more than two weeks 4. Growth rate –lesion exhibits rapid growth. 5. Bleeding –lesion bleeds on gentle manipulation 6. Induration-lesion and surrounding is firm to the touch 7. Fixation –lesion feels attached to adjacent structures. Incisional biopsy: An incisional biopsy is a biopsy that samples only a particular portion or representative part of a lesion If a lesion is large or has different characteristics in various locations more than one area may need to be sampled . 3 Indications: Size limitations Hazardous location of the lesion Great suspicion of malignancy Technique: Representative areas are biopsied in a wedge fashion Margins should extend into normal tissue on the deep surface. Necrotic tissue should be avoided. A narrow deep specimen is better than broad shallow one. Excisional biopsy: An excisional biopsy implies the complete removal of the lesion. Indications: Should be employed with small lesions. Less than 1 cm. The lesion on clinical exam appears benign. When complete excision with a margin of normal tissue is possible without mutilation. Technique: The entire lesion with 2 to 3 mm of normal appearing tissue surrounding the lesion is excised if benign. Oral cytology: 1. Developed as a diagnostic screening procedure to monitor large tissue areas for dysplastic changes. 2. Most frequently used to screen for uterine cervix malignancy. 3. May be helpful with monitoring post-radiation changes , herpes, pemphigus. 4. The disadvantages of oral cytological procedure include: 1-Not very reliable with many false positives. 2-Expertise in oral cytology is not widely available . 5.The lesion is repeatedly scraped with a moistened tongue depressor or spatula type instrument . The cells 4 obtained are smeared on a glass slide and immediately fixed with a fixative spray or solution. Aspiration biopsy: Aspiration biopsy is the use of a needle and syringe to penetrate a lesion for aspiration of it’s contents. Indication: To determine the presence of fluid within a lesion To acertain the type of fluid with in a lesion . When exploration of an intraosseous lesion is indicated Aspiration: An 18 gauge needle on a 5 or 10 ml syringe is inserted into the area under investigation after anesthesia is obtained. The syringe is aspirated and the needle redirected if necessary to find the fluid cavity. Principles of surgery: Anesthesia: 1. Block local anesthesia techniques are employed when possible. 2. The anesthetic solution should not be injected within the tissue to be removed, because it can cause artificial distortion of the specimen. 3. When blocks are not possible, infiltration of local anesthesia may be used locally, but the solution should be injected at least 1 cm away from the lesion Tissue stabilization: specimens should be stabilized either by: 1. Digital stabilization 2. Specialized retractors/forceps 3. Retraction sutures 4. Towel clips Hemostasis : Suction devices should be avoided 5 Gauze wrapped low volume suction may be used if needed Incision: 1. Incisions should be made with a scalpel 2. They should be converging 3. Should extend beyond the suspected depth of the lesion 4. They should parallel important structures 5. Margins should include 2 to 3 mm of normal appearing tissue if the lesion is thought to be benign 6. 5mm or more may be necessary with lesions that appear malignant, vascular, pigmented, or have diffuse borders. 7. Choose the most suspicious area. 8. Avoid ulcers, sloughs or necrotic areas 9. In large lesions, several areas may need to be sampled 10.Include every fragment for histopathological examination. Handling of the tissue specimen Direct handling of the lesion will expose it to crush injury resulting in alteration the cellular architecture. Fixation: 1. The specimen should be immediately placed in 10% formalin solution, and be completely immersed. 2. Fixation is necessary to prevent autolysis and destruction of the microscopic features of the specimen. 3. Fixative must diffuse into the specimen completely before processing. Margins of the biopsy: Margins of the tissue should be identified to orient the pathologist. A silk suture is often adequate. Illustrations are also very helpful and should be included. Surgical closure: 1. Primary closure of the wound is usually possible 2. Mucosal undermining may be necessary 6 3. Elliptical incision on the hard palate or attached gingival may be left to heal by secondary intention. Biopsy data sheet: A biopsy data sheet should be completed and the specimen immediately labeled. All patient’s history and descriptions of the lesion must be accurate Intraosseous and hard tissue biopsy: Intraosseous lesions are most often the result of problems associated with dentition. Indications for intraosseous biopsy: Any intraosseous lesion that fails to respond to routine treatment of the dentition Any intraosseous lesion that appears unrelated to the dentition. Clinical examination: Palpation of the area of the lesion with comparison to the opposite side. Any radiolucent lesion should have an aspiration biopsy performed prior to surgical exploration. Material obtained from the aspiration will provide valuable information about the lesion if it is: 1. Solid 2. Fluid filled 3. Vascular 4. Without contents Principles of surgery: 1. Mucperiosteal flaps should be designed to allow adequate access for incisional/ excisional biopsy. 2. Incisions should be over sound bone. 3. Cortical perforation must be considered when designing flaps . 4. Flaps should be full thickness 5. Major neurovascular structures should be avoided 6. Osseous windows should be submitted with the specimen 7. Osseous perforations can be enlarged to gain access 8. The tissue consistency and nature of the lesion will determine the ease of removal 7 9. Incisional biopsies only require removal of a section of tissue 10.Soft tissue overlying the lesion should be reapproximated following thorough irrigation of the operative site. 11.The specimen should be handled as previously described. When to refer for biopsy: 1. When the health of the patient requires special management that the dentist feel unprepared to handle 2. The size and surgical difficulty is beyond the level of skill that the dentist feels he / she possesses 3. If the dentist is concerned about the possibility of malignancy. 8