Non-keratinizing squamous cell carcinoma (NKSCC) is a rare malignancy of the nose and paranasal sinuses which is characterized by a unique anastomosing ribbon-like growth pattern with absent of limited maturation and keratinization. NKSCC accounts for 10-27% of sinonasal squamous cell carcinomas and some of the NKSCCs are reported to be associated with high risk-HPV infection. Advanced lesion can involve the oral cavity with oral symptoms of palatal bulging, surface ulceration mimicking salivary gland tumors. Herein, we report a case of NKSCC of a 46-year old male, which clinically presented as a bulging mass on the mid palate and mimicked a palatal salivary gland tumor. We reviewed the clinical and histopathological considerations required for differential diagnosis of sinonasal carcinoma involving the oral cavity.

Oral-derived bioresources(ODBs) for human-derived material research have been mainly sampled by individual researchers. Difficulties in ODB secure has impeded advances in dental research and associated industries. ODBs have been obtained in a few biobanks within general hospitals, yet the amount of oral-derived specimens is relatively low compared to other organs and lacked practical clinical data. Recently, biobanks of dental hospitals have started systematic management in South Korea, thus these biobanks are expected to invigorate high-quality ODB banking in the field. In this review, we will discuss the collection and utilization of OBDs, such as teeth, dental plaque, gingival crevicular fluid and saliva, and the need of dental hospital-based biobanks.

Parosteal osteosarcoma, a subtype of juxtacortical osteosarcoma, has a better prognosis compared to central osteosarcoma with a relatively low risk for recurrence and metastasis. Rarely, it can arise synchronously with other malignant tumors. Synchronous malignancies are defined as the occurrence of a second primary malignancy within 6 months of the appearance of the first malignancy. Here in, we introduce a 64-year-old woman who visited the Department of Oral & Maxillofacial Surgery, Yonsei University Dental Hospital with a 2 year history of a whitish verrucous lesion on the palate. She presented an exophytic mass on mandible during the following visits. Histopathologic evaluation revealed a synchronous parosteal osteosarcoma and squamous cell on right mandible and a precancerous verrucous leukoplakia on the palate.

Lingual cyst is a clinical term indicating a cyst occurring within the tongue. Various disease may clinically present as a lingual cyst, such as foregut cyst, dermoid cyst, thyroglossal duct cyst, salivary duct cyst, hemangioma and ranula. In general, lingual cysts are asymptomatic but may cause airway obstruction, feeding or swallowing problems. Most of these lesions can be simply treated by surgical excision with good postoperative healing and low recurrence rate. Apart from that, histopathological diagnosis of the lesion is important because it means the origin of the lesion. Thus it is important to rule out several origins of lingual cyst histopathologically, because it might be related with adjacent anatomical structure or may indicate cysts on other sites. Herein, we reported a case of lingual cyst with columnar epithelium at the ventral tongue of a 46-year old man and reviewed the clinical and histopathological considerations required for further classification in lingual cysts.

Odontogenic keratocyst (OKC) is aggressive compared to other odontogenic cysts, but its malignant transformation is extremely rare. Odontogenic carcinoma may arise from an odontogenic cyst such as OKC. Here in, we introduce a case of odontogenic carcinoma assumed to have arisen from a preexisting OKC. Abnormal clinical and radiologic features seen in a previous or existing cyst may be warning signs of malignant transformation.

Lymphomatoid granulomatosis (LYG) is an uncommon Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorder distinct from lymphoma. LYG primarily occurs in the lung with or without accompanied lesions in the skin, central nervous system, kidney, gastrointestinal tract, nose, eyes, liver and oral cavity. Solitary extrapulmonary LYG is extremely rare, and whether solitary lesions progress onto pulmonary development and dysfunction is controversial. Herein, we report a case on a solitary LYG in the maxilla gingiva with bone exposure in a patient who had been taking methotrexate for rheumatoid arthritis.

Juvenile xanthogranuloma (JXG) is a benign histiocytosis that occurs in the pediatric population. Cutaneous JXG is the most common form, while extracutaneous lesions, including oral JXG, is extremely rare. Cutaneous JXG can occur as multiple lesions and may have systemic visceral involvement, but this is not seen in oral JXG. In this case, we report a solitary oral JXG at the gingiva in a 3-year old male.