Orthokeratinized odontogenic cysts are developmental cysts that occur in the jaw that account for approximately 7%–17% of all cysts in the jaws. Studies have shown that malignant transformation of odontogenic cysts most often occurs in inflammatory cysts, such as periapical cysts, but malignant transformation of orthokeratinized odontogenic cysts has also been reported. In this report, we present an uncommon case of squamous cell carcinoma arising from an orthokeratinized odontogenic cyst.

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.

Clear cell odontogenic carcinoma (CCOC), a very rare neoplasm located mostly in the mandible, has been regarded as a benign tumor. However, due to the accumulation of case reports, CCOC has been reclassified as a malignant entity by the World Health Organization. Patients with CCOC present with regional swelling and periodontal indications with variable pain, often remaining misdiagnosed for a long period. CCOC has slow growth but aggressive behavior, requiring radical resection. Histologic analysis revealed the monophasic, biphasic, and ameloblastic types of CCOC with clear cells and a mixed combination of polygonal and palisading cells. At the molecular level, CCOC shows the expression of cytokeratin and epithelial membrane antigen, along with markers that assign CCOC to the sarcoma family. At the genetic level, Ewing sarcoma breakpoint region 1-activating transcription factor 1 fusion is regarded as the key feature for identification. Nevertheless, the scarcity of cases and dependence on histological data delay the development of an efficient therapy. Regarding the high recurrence rate and the potential of distant metastasis, further characterization of CCOC is necessary for an early and accurate diagnosis.

Clear cell odontogenic carcinoma (CCOC) is an extremely rare odontogenic neoplasm; Only a few cases have been reported in the English literatures. It displays a propensity for the mandible, most commonly presenting in the fifth to seventh decades, with a female predilection. The clinical and radiological manifestations are multiple and the diagnosis is histological. Histological feature is of large islands and strands of uniform cells with round or ovoid nuclei and clear cytoplasm. Clinically, painless swelling is the most common symptom, followed by pain, teeth mobility, and paresthesia. CCOC has a good prognosis after surgery. This case report presents the histopathological and clinical features of CCOC excised from the mandible.

Primary intraosseous odontogenic carcinoma (PIOC) is a carcinoma arising within the jaws, putatively developing from remnants of odontogenic epithelium. We describe a case of PIOC arising from odontogenic cyst affecting the left posterior mandible of 72-year-old Korean man. Clinical examination showed a symptom-free hard mass. There was no evidence of ulceration, and there was no pain or bleeding. The overlying mucosa was intact and no regional lymph nodes were palpable. Clinical and radiological studies for other distant primary sites were negative. Radiographically, the tumor showed multilocular radiolucency with a noncorticated, ill defined border surrounding an impacted third molar tooth. Histology exhibited sheets or islands of nonkeratinizing malignant epithelial cells with minimal clear cell component in continuity with begin or dysplastic cyst lining epithelium. Immunostaining for PCNA and p53 protein showed a higher percentage of positive cells and more intense staining in the carcinomatous tissues than in the benign and dysplastic lesions.

Clear cell odontogenic carcinoma (CCOC) is a very rare malignant neoplasm of jaw, with a significant clear cell component. It is nearly three times as common in the mandible with distinct female predominance. Past, identified as locally invasive tumor, CCOC is now considered to be malignant neoplasm, showing distant and regional lymph node metastasis. CCOC is histopathologically characterized by large glycogen-rich clear cells, often intermixed with eosinophilic cells. When diagnosing CCOC, ruling out salivary gland tumors, such as mucoepidermoid carcinoma or clear cell adenocarcinoma is important because they have overlapping histologic features with CCOC. Here in, we report a case of CCOC involving the right maxillary sinus of a 72-year-old female.

Angiogenesis is a process with a coordinated sequence of endothelial cell division, selective degradation of vascular basement membranes, and surrounding extracellular matrix with migration of theses cells that result in a new capillary growth from preexisting vessels. These processes are controlled by numerous different molecules. Among these, Vascular Endothelial Growth Factor(VEGF) is an endothelial cell-specific mitogen with a potent ability to induce microvessel permeability and angiogenesis. In this study, tissue samples of odontogenic keratocyst(10 cases), ameloblastoma(10 cases), adenomatoid odontogenic tumor(10 cases), calcifying epithelial odontogenic tumor(10 cases), ameloblastic carcinoma(2 cases) were obtained, and all specimen were routinely fixed in 10% formalin and embedded. Serial 5μm thick sections were cut from paraffin blocks. And the immunohistochemical staining, characteristics of VEGF about the cyst & tumor were observed & obtaned the results from this study. We presume that the growth of cyst is depends on not a differentiation but an epithelium & connective tissue. But, in odontogenic tumor, we presumed that the growth of tumor is influenced on inflammation & surrounding stimulus & vascular growth and supply. Therefore, it should be suggested that study on the growth of tumor and vascularity must be carrying out in this immunohistochemical study.