Systematic Approach To Assessment Of Oral Mucosal Lesion 1) History Of Current Illness – onset, location, intensity, frequency, duration aggravating &or relieving variables better, unchanged or worse over time 2) Medical, Tobacco &or Alcohol history – medical conditions medications & allergies tobacco & alcohol ( type, frequency, duration ) 3) Clinical examination extra oral intra oral lesion inspection 4) Differential Diagnosis 5) Diagnostic Tests 6) Definitive Diagnosis 7) Suggested Management Diagnostics Aids Haemogram, biochemical analysis, bacteriological examination, Immunostaining, Molecular Biology Tests, Imaging X-rays CAT Scan Magnetic Resonance Imaging (MRI) Functional & Metabolic Imaging— a) Positron Emission Tomography b) Magnetic Resonance Spectroscopy Ultrasonography , less commonly used for oral lesions Biopsy , Exfoliative Cytology Screening Devices Photography, Referrals. HAEMATOLOGY Essential for diagnosis of Blood Dyscrasias like anaemias, Leukaemia, Multiple Myeloma, Leukopenia, Haemophilia, Purpura etc. Useful in diagnosis of other conditions like infections, sore tongue, recurrent apthae which are associated with anaemia. Completely filled request form with sufficient clinical details is essential for pathologist to check whether appropriate tests are ordered. MICROBIOLOGY It is unfortunate that this aspect of investigation is not explored as it should have been utilized. Pus, plaque, aspirate or scrapping should be send for Direct Gram Staining of Gram +ve , Gram –ve bacilli & cocci, Actinomycetes associated ray-fungus, ZN staining for Mycobacteria Or for PAS staining for Candida PAP smears for Virally infected cells. Especially important in acute ulcerative gingivitis, candidiasis, herpetic lesions, measles, or for diagnosis of various vesiculo-bullous lesions. Viral culture is rarely required. Rapid diagnosis can also be achieved by ELISA. IMMUNOSTAINING Has revolutionized histological diagnosis & made complex techniques of electron microscope redundant. Principle- There is highly specific binding between Antibody & Antigen to stain specific molecules within the tissues. Two basic methods are used either Direct or Indirect , & the final product is either labeled with a Fluoroscein dye or an enzyme such as peroxidase. Important in diagnosis Pemphigus, Pemphigoid, Multiple Myeloma, or other undifferentiated malgnancies, identification of Viral infections like HPV, EBV, HSV MOLECULAR BIOLOGY TESTS Useful particularly in screening for & identification of Genetic abnormalities like Down’s syndrome. Rapid diagnosis of bacteria ( Mycobacteria), Viruses HPV, HIV Diagnosis of malignancies having genetic abnormalities like chromosomal translocation in Leukaemia. Diagnosis of some forms of Lymphoma which cannot be categorized by routine biological methods. Tests are like PCR, In-Situ-Hybridization. PCR is especially important for Mycobacterial infections since these method is rapid, more sensitive, can differentiate different types of MB with high degree of precision. PCR is ideal to investigate enlarged lymph nodes in neck & recently is being used to detect micrometastases of tumors. PHOTOGRAPHY Photography or computerized video imaging is an valuable adjunct to clinical record. It is 1) useful to monitor lesions which vary in the course of long follow-up like leukoplakia. 2) useful to explain to patients about their condition 3) To show patients the effect of treatment. OTHER CLINICAL TESTS like urine analysis in diabetes is essential in case of repeated candidal or periodontal infections Autoimmune conditions require rigorous tests to detect systemic involvement Bence Jones Protein in Multiple Myeloma Paul Bunnel Test in Infectious Mononucleosis TEMPERATURE Temperature recording of patient is very essential to differentiate facial inflammatory edema from cellulitis. It indicates systemic effects of infections & the need for aggressive therapy. REFERRALS to concerned medical faculty is very essential for further investigations especially when oral cause is eliminated, & also to exclude any severe systemic illness & refer the patient back to dentist IMAGING Imaging is useful for diagnosis of all tumors that are not accessible to clinical evaluation or endoscopy. Sites in which imaging plays a key role for diagnosis are brain, lung, breast, mediastinum, abdominal organs, bones, etc. The choice of imaging system to be selected , for a given pt. depends upon its physical capabilities. Imaging techniques allow differentiation of benign from malignant lesions, & assist in accurate staging of disease Conventional XG provides the highest spatial resolution & is suited best for barium studies of GIT, breast & bone diseases. CAT SCAN CT scan has higher density discrimination than conventional XG, & is best suited for distinguishing differences between soft tissues, fluid, fat & other structures. Recent innovation include Spiral (helical) CT, Multiphase Imaging, Multi detector scanning. Spiral CT is currently preferred for detecting Pulmonary & liver lesions prior to surgery & for surgical planning of Pancreatic & renal cancer treatment Magnetic Resonance Imaging Benefits- superb soft tissue contrast, multiplanar & 3D acquisition, freedom from ionizing radiation & bony artifacts, ability to acquire biological & physiological information. MRI is choice for evaluating tumors of brain, HN, spine, breast, liver & adrenal glands. Positron Emission Tomography PET creates images that represent metabolic activity of underlying tissue processes like glucose, oxygen, amino acid metabolism. Commonly used radiotracer for tumor imaging is glucose analogue 2[F-18] fluoro 2deoxyDglucose (18-FDG) FDG enters cells & is phosphorylated to FDG-6- phosphate, which becomes trapped within malignant cells with high glucose metabolism. PET is the most accurate non- invasive technique for detecting & staging Lung CA, detecting intrahepatic metastases, identifying metastatic deposits in nodes less than 1 cm dia. Magnetic Resonance Spectroscopy MRS is powerful , non-invasive method for studying tumor biochemistry & physiology. It measures signals from chemical compounds within tissues. 31 P MRS provides information on tissue energetics & pH while I H MRS provides information on cell membrane synthesis & degradation, reflecting cellular proliferation & necrosis. MRS can provide diagnostic information on tumor grade & are also used to monitor tumor response to therapy. ULTRASOUND Ultrasound has major advantage that ionizing radiation is not used, & is often used for evaluating thyroid, parotid, testicles, liver, kidneys, & pelvic organs. It has limited scope in Oral cancer diagnosis BIOPSY It is the procedure of removal of living tissue for the purpose of microscopic examination Methods for obtaining the material— 1) surgical scalpel biopsy 2) surgical removal by Cautery or High Frequency Cutting Knife 3) punch biopsy 4) FNAC 5) FNAB 6) Exfoliative Cytology Point’s to be considered before biopsy 1) Why is biopsy been taken ? e. g to confirm a mucosal disease such as Lichen Planus, cyst etc. Or to rule out malignancy- then take it from the edge of the lesion 2) Is the biopsy incisional or excisional ? For excisional biopsies a margin of surrounding normal tissue will be required. Provisional clinical diagnosis is especially important in guiding the technique to be used & tissue handling For lesion such as Mucocele, Lichen Planus, Fibroepithelial Polyp, Pyogenic Granuloma, Leukoplakia, epulis incisional biopsy can be performed on OPD basis But for suspected lesions of Malignancies, salivary Gland tumors, Pemphigus, Granulomatous Diseases Referrals to Hospitals is essential. Periapical surgical material should always be sent for histopathological examination. It is mostly inflammatory ,rarely it can be odontogenic or non- odontogenic cyst, odontogenic tumor. Even rarely it can be bone lesion like giant cell granuloma, multiple myeloma, langerhans cell histiocyosis, or even more rarely malignant metastatic deposits or SCC Occasionally dental hard tissues are sent to rule out abnormality of dentine or enamel Vascular small lesion is excised , no incision biopsy Large Vascular lesions are ablated with Laser or Cryosurgery (no tissue remains for histologic exam. ) Sjogren’s syndrome – confirmation incisional biopsy from lower lip to include at least 5 minor SAL. Glands Limitations of Biopsy 1) invasive procedure, has surgical implications 2) technique is limited to professionals 3) psychological implications to patient’s 4) for large lesions , site selection is difficult 5) has limited sensitivity because of subjective interpretation of examining pathologist Adjuncts to Biopsy All the limitations of biopsy & the need for early diagnosis of oral cancer have underlined the importance of discovering & developing new diagnostic methods & improving existing ones Detecting presence of innocuous lesions & Selecting the site for biopsy can be done by adjuncts like— Supravital staining with Toluidine Blue or By use of Exfoliative Cytology Supra-vital Staining Toluidine Blue is a vital tissue dye which exhibits differential uptake into tissues, resulting in metabolically active areas of lesions being stained a deep blue. T-Blue is effective in differentially staining the nucleus in precancerous & cancerous lesions Helps to delineate the margin of the lesion Positive correlation between degree of dye uptake & presence of chromosomal abnormalities Adjunctive use of T- Blue helps- Identify abnormal lesions Facilitates biopsy site selection Eventual definitive diagnosis Exfoliative Cytology When epithelium becomes seat of pathology, cells loose their cohesiveness & deeper cells shed along with superficial cells . These exfoliated cells are collected & studied Quantitatively or Qualitatively. Collection of cells is done by different physical systems like— -Scraping the mucosal surface -by rinsing the oral cavity -taking saliva samples from pt’s -by using Brush Biopsy Exfoliative Cytology was introduced by George N Papanicolau in 1941 It is a Quick, simple, painless, bloodless procedure Helps check against false negative biopsies Valuable for screening of lesions whose clinical appearance does not warrant a biopsy Apart from Cancers, can be applied to other disease like Candidiasis, EBV related Hairy Leukoplakia, HSV infection, HZ, Pemphigus, Benign Familial Pemphigus, Keratosis Follicularis, HBID, White Sponge Nevus, Pernicious anaemia, Sickle Cell Anaemia Application in Forensic Odontology Oral Brush Biopsy CDX (scan lab) Simple Highly sensitive Risk free for screening for cancer Aids in clinical examination Full trans-epithelial cellular sample is obtained Smears are evaluated with image analysis adapted specifically to detect oral epithelial abnormalities including cancer Can be applied to Precancerous & cancerous lesions & other diseases as well Disadvantages of brush biopsy False negative results, no diagnosis, so difficult to determine appropriate treatment or anticipate whether an additional procedure is necessary. Adds time & cost to the diagnosis of oral lesions without added benefit to the patient Positive results have to be confirmed by routine biopsy The need for 2 procedures delays the diagnosis & this delay may be potentially hazardous Applications of Cytology technique Apart from screening of lesions, Cytology techniques can also be used for other valuable purposes like evaluating Response to Radiation therapy, Molecular analysis, Immunohistochemistry Response to Radiation therapy useful to study radiation response of oral tumour, and the changes are like– cellular enlargement, cytoplasmic granulation, multinucleation, micronucleation Micronucleation is accepted as reliable indicator to monitor the effectiveness of therapy Apoptosis – % of apoptotic cells is useful to monitor pt’s reaction to chemotherapy DNA Ploidy analysis to predict the aggressiveness & prognosis of cancers. Molecular AnalysisGene Alterations— Most of the oral cavity carcinogens like chemicals (tobacco), physical (radiation), infections (HPV, candida) are mutagenic agents They can cause changes in gene & chromosome structure by point mutations , deletions, insertions & rearrangements. Some of these changes are spontaneous. These genetic alterations occuring during carcinogenesis can be used as targets for detecting tumor cells in clinical samples. Point Mutations in Tumor Suppressor Gene – P 53 is frequently used genetic alteration in Clinical & Oral Cytology as specific marker in Oral SCC. Aberrations in the 3p, 9p, & 17p chromosomal sites is implicated as high- risk predictor Immunohistochemistry Cytokeratin Expression Profile in smears from oral cavity are used to provide information on cell differentiation status Certain Cytokeratins like K8, k 19 are useful if not definitive indicator of malignancy Summary Of Oral Cytology Cytologic studies are easy, simple, rapid, non-aggressive & relatively painless. It is accepted well by the pt’s & are suitable for routine application in – Screening Programmes Early detection of suspect lesions Pre & Post Operative monitoring of confirmed malignant lesions Screening For Oral Cancer Unaided visual examination Palpation Radiographs Supplemental screening techniques- 1) use of special wavelength lights 2) Chemiluminescence 3) Use of dyes for selective staining 4)Laser induced Fluorescence Emission after exposure to photosensitizer 5-Aminolevulinic Acid Screening devices available at present Microlux DL (Ad Dent) Velscpoe (LED) (Dental INC) Vizilite & Vizilite Plus (Zila Pharmaceuticals) Microlux /DL It is a hand held device, that uses light emitting diodes (LEDs) as illumination source. Prior to exposing the mucosa to the light, the pt. rinses with 1% acetic acid for 30-60 seconds. Upon illumination, the abnormal tissue will appear white (aceto-white VELSCOPE VEL-Scope is hand held device that emits a blue light to fluoresce the mucosa. No pre-rinse is required . The amount of fluorescence depends on the health of mucosa. When exposed to blue light , normal mucosa emits a pale green autofluorescence, while abnormal tissue appears dark green to black. Inflammed mucosa results in loss of fluorescence (false +ve) VELScope is used to- —delineate the extent of visible lesion —identify lesions that are difficult to appreciate by unaided visual examination. Vizilite & Vizilite Plus Vizilite & Vizilite Plus is a hand held device that emits Chemiluminescent light. The pt. rinses with 1% acetic acid for 30-60 sec. The device then illuminates the oral cavity. Abnormal areas appear white ( aceto-white) The light increases both the sharpness & brightness of lesions. CONCLUSION Although Biopsy still remains the gold standard for diagnosis, recent advances -in the field of molecular biology -advent of new screening devices -newer diagnostic technologies has widened the horizon of diagnostic approaches . It won’t be too long before these technologies reach down to the level of use from research to well being of the patient’s