Cellular myxoma is an uncommon type of myxoid benign tumor, predominantly occurring in adult female patients aged >40 years. This report aims to document a case of cellular myxoma that occurred in the buccal mucosa. Compared to intramuscular myxomas, cellular myxoma demonstrates hypercellularity and vascularity. Its manifestation in the soft tissue of the head and neck area is exceptionally rare. Generally, cellular myxoma manifests as a firm and immovable mass covered with normal oral mucosa, with no associated clinical symptoms. Homogenous low signal intensity on T1-weighted scans and high-signal intensity on T2-weighted magnetic resonance scans reveal cellular myxoma, as most lesions show well-defined margins and heterogeneous contrast enhancement. The significant histologic features include a focal or diffuse increase in cellularity with fibroblast-like cells and vascularity with an abundant collagenous matrix. Our presented case reflects these facts examinations, based on which a final diagnosis of cellular myxoma was made. Immunohistochemistry revealed locally and diffusely positive SMA and CD34. The clinical tendency of cellular myxoma with hypercellularity may affect the production of myxoid and collagenous substrates, and if complete resection is not performed, the possibility of local recurrence in the primarily affected region remains. Hence, complete surgical excision was performed under general anesthesia, and follow-up until a year after treatment revealed no observed recurrence. To achieve precise diagnosis and complete treatment without local recurrence, several diagnostic examinations should be considered.

Extranodal intraoral Hodgkin lymphoma is not common. We report the case of a 78-year-old male patient with ulcer of the mandibular oral mucosa that was not cured for about 3 weeks. In biopsy and histopathologic examination, it was found to be extranodal intraoral Hodgkin lymphoma. Early diagnosis of oral lesions led to early detection of lesions of the opposite neck lymph node in an additional PET-CT scan. We report this case and review relevant literature.

Oral squamous cell carcinoma (OSCC) develops through multistep process, that is, from normal mucosa to hyperplastic area and progressed to dysplasia, carcinoma in situ, and finally to invasive carcinoma. The purpose of this study is to investigate the histological types of the transitional area from normal oral mucosa to invasive carcinoma for the baseline data to search intermediate end point markers for early detection of OSCC. For this purpose, we reviewed the 85 patients who were diagnosed as OSCC in the Department of Oral Pathology, Yonsei University College of Dentistry, from 2002 to 2008. We classified these histopathologic findings by light-microscopy, according to the histologic pattern of transitional areas. As results, stepwise transformation from normal oral mucosa, to dysplasia and to OSCC was shown in 47 patients. Intermittent lesions were seen in 16 patients, in which normal oral mucosa, dysplasia, and OSCC were alternately arranged. Twenty two patients showed abruptly transformed to OSCC from normal oral mucosa. These preliminary data will be used for searching biomarkers for early detection of OSCC.

Traumatic eosinoph ilic gra nul oma(TEG) of the oral mucosa is considered to be a reactive benign lesion, which commonly ma nifests as an ulcer with eleva ted and indurated borders Clinically. this lesion simulates a maligna nt tumor Hi s to logy shows a diffut;e‘ dense. polymorphic. and eosinophil-rich cellular infiltrate. which extends deeply into the un derl ying soft ti ss ues‘ A major constituent of infïltrates is a population of mitotically active, large. atypical monol1 uclear cell s . Immunohi stologic eval uation of the large atypical cells has suggested a myofibroblastic 0 1' histi ocyti c origi 1γ However ‘ recent reports have shown that these cells are positive for CD30 antigen. We have descr ibed a case of ora l mucosal lesions with featu res of TEG that had a CD68 posite atypical cells. The large cells showed s trong pos itive for CD68‘ but negative for CD30. The sma ll Iymphocy tic cells exprerssed CD3. This case was interpreted as an atypical histiocytic g ran uloma .

Oral mucosa is made of stra tifi ed oral epithelium(that forms the surface) and subjacent connective tissues Alt hough oral mucosa lines the oral cavity, and thus provides a barrier between external and inte1'na l(tissue) envi1'onment, it exp1'esses regional va1'ia tions in its clinical appearance based on its structu1'e(ker atini zation/ non- ke1'atini zation; nature of connective tissues ; vascul arity, etc.) . The structu1'e of or al mucosa a lso reflects its flln ctional adapta ti on. Available liter ature indicates t hat oral mucosa may be viewed as masticat ory, lining 0 1' specialized types, aJl of which remains continuously moist and unexposed to light. Oral mucosa, however, is subj ected to daily wear and tear due t o the natllre of food , environmental chernicals , t oxins and met abolites. Hence, an understanding of the biological behavior of its constituents cells and ext1'acellular matrice s , tha t• are in constant s tate of adapt ive changes, is usefll l. Oral epithelium is a multi - Iayered and multi - functional dynarnic system that separates the o1'al environment f1'om the va1'ied nature of the s llbj acent connective tlsslles The connective tissue is eithe1' loose or dense collagen ous, muscula r or osseous, and may contain glands. Thus,oral epithelia play a critical 1'ole in the mainten ance of homeost atic effi ciency of the environment of both the o1'al cavi ty and subj acent connective tisslles. The structure and fllncti ons of the oral epithelial cells are regulated by a complex interplay between genetic and environmental fa cto1's, the knowl edge of which is unfolding only recently. The fundamental prernise on whi ch 3-dimensional organization of oral epithelial integrity and st a bility are maintained is the principl e of st eady-state syst em. The basic featU1'e of the steady- st ate syst em is t he 1'egulation of cellula1' and t issue homeost atic mechanisms. Since during its ontogeny, oral epithelial cells are subj ect ed to daily wear and tear , resulting from external mechanical and chernical facto1's, a 1'eservoi1' of cells, with regene1'ative capacity(va1'iously labeled in lite1'ature as p1'ecurso1' ceJls, p1'ogeni tor cells OI‘ stem cell s) that can maintain the steady-state system of oral epi thelia, are 1'equired. Such a reservoir of cells are located in the basal layer of oral epithelia. These cells proliferates, differentiate into ker atinocyt es, and are lost through desquamation or a poptosis to maintain the steady-state syst em and thus equilibrium of tissue homeostasis