Amelobl astic carcinoma(AC) is a maJignant coun terpart of ameloblastoma. histologically characteri zed by amelobJastomatolls feature with obviollS cytologic a typi a . AC is a r are malignant tumor with poten t iaJ of metastasis‘ asssllmed to occur far less tha n 1% of ameloblastoma . Nearly 80% of ACs have been reported to occur in the mandibJ e. The allthors reviewed 5 cases of AC in Department of Oral PathoJogy. SeouJ National University from 2005 to 2007 clini copathologically according to age, sex. location and clinical findings. They occllrred at the age from 46 to 75 years wi th average age of 60 Four cases occurred in male and 1 in female‘ showing prediJ ection for ma le‘ While four cases occu rred in the maxilla , including 3 cases in the maxillary molar area and 1 in the maxiJJ a ry premola l‘ a rea, only 1 case occurred in the mandibJe. AC showing predorninance in the maxilla over t he ma ndible in our cases in contrast to other case reviews. Three patients presented painful large oral lllcer at the time of admi ssion, a nd other 2 patients presented swol1en mass around the gingivae and alveoJar bone While the clini cal impression of 3 patients were ma lignant tllmor, other 2 patients were amelboJastoma and nicotine stomatitis. The dllration of symptoms before final diagnosis has ranged from 4 months to 2 years Radiogr a phicalJy they showed poorly demarcated radiolucent lesion with irreg비 ar bony destruction. Resected tumors were measured as 6.0X4.5x4.0cm‘ 0‘ 7xO.5xO.3cm, 5.0 x 4.5 X5.0cm. 0.8xO.6 XO.5cm, and 5cm diametel mass respecti vely. Microscopically lymph node metastasis was confirmed in 1 case, but not in others . The tumors showed basic histologic featu re of ameloblastoma with apparent cytologic atypia sllch as pleomol‘ phism‘ hyper chromatism and atypical ffiJ tOSIS Individua l neoplastic cells displayed wide va riations from case to case‘ showing c lear cells with faint PAS positive granules‘ isolated round cells with abundant cytoplasm. s quamoid ceJls and polygonaJ cell s . [mmunohis toc hemical survey was done in 2 cases. all of which showed positivity to pan-cytoker atin a ntibody and p53 a ntibody‘ but negativity to HMB-45, S-100, and SMA One case recurred twice during 2 yeal's after surgery. But 3 cases showed no evidence of recurrence and metastas is. lt seems to us t hat AC have the potential of metastasis and reCllrrence.

Epithelial-mesenchymal transition(EMT) plays a pivotal role in the convers ion of earl y s tage tumors into invasive malignancies‘ and has been shown to be regulated hy the transcri ptional factor. Snail. Recent ly‘ actlvatlon of the phosphatidylinositol 3' kinase (PI3K)/따<:T axis is emerging as a centra l feature of EMT‘ However. it is unclear whether the phosphorylation of AKT regulate the expl'ession of s nail in ora l cancer cell underwent EMT. T。 investigate a role of p-AKT in EMT, we assessed the effects of inhibi ting p-AK1' activity in oral squamous can cer cells(KOSCC-25B) using PIAs, structurally modified phosphatidyli nositol ether lipid analogues(P1As) . PIAs de creased phosphorylation of c-Jun N-terrninal Kinase(JNK) and increased phosphorylation of glycogen synthase kinase 3beta(GSK-3beta). Inhibition of p-AKT ir빼ce d down regulation of Snail and Twist. but Sip1 regulated independent of p-AKT inhibition. Also inhibi tion of p-AKT dec reased cell migration and invas ion. Therefore our results implicate that p-AKT may contribute to the translocalization of sna il in the EMT associated with canceJ cell rnigration and invasion

Cholesterol granuloma(CG) occurs frequently in association with chronic middle ear diseases. pa rti cul arly dis eases in the mastoid antrum a nd ai r cells of the tempora l bone. and much less frequent ly in paranasal sinuses, It occurs f1'eq uentJy seconda1'Y to massive hemor1'hage of oral and pal'aol'aJ cysts, Howeve1'. It has nevel' been I'eported to OCCUI' solely wi thout any association of pl'eexisting lesion in the mandibJe We expel'ienced development of unusuaJ cholestel'ol granuloma in the mandible, Seventy year old female pl'e sented diffuse ha1'd swelling on the left mandibular a rea with Iymphadenopathy in the left cer vical Iymph node Radi og1'aphic exarnination showed a well circumsc ribed multi locular radiolucency resembling soap bubble appeara nce with tooth di s placement and root resorption‘ leading to the radiogrphic imp1'ession of dentigerous cyst 0 1' 。dontogenic cys t or amelobJas toma, CT showed bucco-lingua lly undul ating expansi le lesion with co rticated ma l'gin from the left posterior mandibular bocly to the anterior ramus. including #46, #47 ancl #43. and the mass containing in the lesion showed s lightly lower a ttenuation than muscJe leading to the impression of ameloblastoma, The mass aftel' surgical excis ion composed of 3 sac like structures, measuring 4,1 cm, 1, 3cm ancl 1.4cm in diame ter respectively, One sac was t ightl y a ttached to the #46. l'eRembling dentigerous cyst, Mi croscopic examination showed a large numbel' of c h이 es te rol clefts in association with hemol'rhage, hemosiderin pigments and fO l'eign body giant cells, There was no evidence of cyst 0 1' other lesions, CG should be taken into diffe l'enti a l diagnosis in addition to odontogenic cysts and tumors when radiographica lly well ci rcumscribed multilocuJal' radiolucent lesion occurs

Although a number of molecules have been implicated in the metastasis of oral squamous cell carcinoma (OSCC) , the precise molecular mechanisms that deterrnine the direction of rnigration and invasiveness of OSCC cells into the lymph nodes remain unclear, Chemokines are a superfarnily of small structurally related heparin- binding proteins‘ which have been identified as attractants that control the rnigration of leukocytes‘ especia lly during imrnune and inflammatory reactlOns Moreover, recent studies have demonstrated that several types 。f cancer express chemokine receptor‘s and use chemokines to metastasize to the target organ, However, there h ave been few reports on biological behaviors by downregulation 0 1' CXCR-4 in ora l cancel‘ cells We tried to screen several OSCC cell lines in order to obtain a suitable cell line model which had the cha ract eris tic of the constitutive ly expressed state of CXCR• 4 Of the several OSCC cell lines, only KOSCC-25B showed the high expression of CXCR-4 in both RT-PCR and Western blot analysis, siRNA-CXCR-4 infected subclones of KOSCC-25B(Si, 3‘ Si 1이 showed downregulation of CXCR-4 expression as expected‘ At serum-free co ndi tion‘ Si.3 s ubclone s ignif icantly decreased cell proliferations at 24 h and 48h and Si, lO subclone significant ly dec reased cell proliferations at 24 h Si ,3 clone dec reased to 67 ,4% and Si,lO clone to 65 ,5% in comparison to vector infected cells These data suggest that the downregulation of CXCR-4 expression could induce anti-rnigratory and ant i- rni g ratory effect

Epithelial myoepithelial carcinoma(EMC) is an uncommon malignant sali va ry gland neoplasm, compri sing about 1% 。f salivar y gland neoplasms, They are histologically composed 01' biphasic cell s such as myoepithelial cells and ductal cells EMC occurs predominantly in the major salivary glands, par t icularly in the par otid gland, They have been reported to occur onJy 10-15% in t he intraoral minor salivary glands, The authors experi enced 4 cases of EMC in Department of Oral Pathology in Seoul National University Dental Hospital from 1995 to 2007‘ and reported them with revi ew of li terature, They occurred at the age [rom 34 to 75 years with average age of 54, Three cases occurred in f'emale and 1 in male, showing predominant occurrence in female, Al I of them occurred in the f100r of mouth Three patients presented localized swollen mass at the time of admission, One patient manifested pain with surface n ecrotic ulcer, and others did not complain any symptoms, The duration of symptoms before diagnosis has ranged f rom three mont hs to 2 years in our cases Microscopically, they growed in double layered ductal structure composed 。f' ductal cells of the inner luminal layer which showed positive immunohistochemical reaction to cytokeratin and rnyoepithelial cells 01' the outer peripheral layer identifi ed by the positive reactivity to S-100 and srnooth muscle ac tin antibody, They did not show perinem al invasion‘ but invasíve growth into adjacent tissue, AII of them did not show in vasion into t he underlying bOl1e While 3 pat ients were treated with total excision of tω110 1' mass wi thout n。 evidence of recurrence a ncl metastasis, a 75 year old patient gave up receiving t reatment at the t irne of diagnos is, and then died 01' the cancer 5 years after init ial diagnosis, It seems that EMC of the intraoral minor salivary gland is a tumor 01' low grade malignancy with low potent ial of recurrence and metastasis

Oral squamous cel1 carcinoma(OSCC) is the most common malignancy of head neck region. Typically OSCC cells s how persist ent invasion that frequently leads to local recurrence and distant lymphatic metastasls However, molecular mechanisms of invasion of OSCC remain poorly understood. Her e we identifi ed periostin, interferon induced transmembrane protein l (IF1TM1) and wingless-type MMTV integration site family, member 5B(WNT5B) , as invasion promoting molecules in OSCC by comparing gene expression profiles between a parent OSCC cell line(MSCC-l) and its highly invasive clone(MSCC-1nvl). Overexpression of periostin, IFITMl and WNT5B mRNAs were confirmed in MSCC-1nvl by RT-PCR. Transfection of these molecules promoted invasion of OSCC cells Moreover , siRNA t r eatment of these molecules suppressed invasion of cancer cells in vitro I nter estingly, Periostin, 1F1TMl and WNT5B were highly expressed in OSCCs in comparison with nonnal tissues. 1n an orthotopic mouse model of OSCC, periostin-overexpressing cells metas tasized spontaneously to cervical lymph nodes and t o t he lung through their aggressive invasiveness. These findings suggest that peri ostin, IFITMl and WNT5B play important roles for invasion and of OSCC and can be prognostic markers and therapeutic t argets of OSCC.

The incidence of oral cancer varies widely worldwide. Its treatment often produces significant functiona l and cosmetic morbidity and its mortality continues to be high. Strategies for diagnosing, managing and preventing the disease must be based on an understanding of r isk factors and the pathogenesis of the disease locally. The World Health Organizat ion has documented that few countries have a comprehensive a pproach to the diagnosis , management and prevention of cancer at various anatomic sites. This presentation will review the United States’ experience with oral cancer and its strategies fo1' affecting incidence and prognosis . The greatest obs tacles are often political and economic, not scientific.