Malignant melanoma is a highly malignant tumor derived from melanocyte. Malignant melanoma of the oral cavity occurs mainly in the palatine mucosa and the maxillary gingiva in men in their 50s. Malignant melanoma can be divided into pigmented and non-pigmented(amelanotic). Among them, non-pigmented malignant melanoma accounts for 2-8% of all malignant melanomas. Pigmented malignant melanoma is detected through changes in pigmentation, whereas non-pigmented malignant melanoma is characterized by no pattern of color change. In this study, at the initial visit, a malignant lesion was suspected and a biopsy was performed. According to the biopsy results, it was diagnosed as polymorphic sarcoma, but the histological examination performed during the operation revealed that it was amelanotic melanoma. As such, the differential diagnosis is important because there is no clinical change in non-pigmented malignant melanoma. Diseases to be differentially diagnosed when non-pigmented malignant melanoma occurs in the oral cavity include squamous cell carcinoma, lymphoma, sarcoma, inflammation, and osteomyelitis. In this study, we report a case that showed the histopathological characteristics of malignant melanoma without superficial pigmentation.

Intraosseous vascular malformation, a representative vascular disease, rarely occurs in the oral and maxillofacial region, especially the maxilla. An 18-year-old female patient was referred to our department with the chief complaint of a radio-opaque mass in the maxilla. A biopsy was attempted at a local dental hospital before visiting our hospital, but it was not completed due to severe intraoperative bleeding. The patient presented swelling and induration in the right maxillary region without pain, local heat, or fluctuation. According to radiographic and clinical examinations, intraosseous vascular malformation or a bone-forming tumor such as aggressive osteoblastoma was suspected. Therefore, an open biopsy of the lesion was performed under general anesthesia. Histopathological examination revealed that the lesion consisted of bony trabeculae with fibrous connective tissue and numerous vascular structures, and the lesion was diagnosed as intraosseous vascular malformation.

Central odontogenic fibroma (COF) is an uncommon slow growing benign neoplasm that is derived from the mesenchymal tissue. Differential diagnoses include fibrous dysplasia, calcifying odontogenic cyst, and central ossifying fibroma. Clinically, the lesion shows expansion of cortical bone. Radiologically, unilocular or multilocular lesion with well-defined borders is found. Histologically, fibroblastic tissues with bundle of collagens including inactive odontogenic epithelium can be observed. In this case report, a 45-year-old male with central odontogenic fibroma of the maxilla is examined. The lesion was surgically removed without any postoperative complications. In order to diagnose the disease properly, histopathologic analysis was performed.

Central odontogenic fibroma(COF) is a very rare benign tumor that accounts for 0.1-1.5% of all odontogenic tumors. Most COF develop in the molar-premolar region in the mandible and anterior to the first molar in the maxilla. Radiographically, the lesions appear as a unilocular or multilocular radiolucent image. Some maxillary lesions have cleft like depression in the palatal mucosa are found. This report presents a COF with external root resorption and palatal soft tissue depression on CBCT images. A 27-year-old man referred for evaluation of unilocular radiolucent lesion with external root resorption in the right anterior maxillary region. On clinical examination, the right anterior maxillary teeth responded positive to the cold stimulus and its response to the vitality test remained within the normal range. On radiographic examination, osteolytic lesion with external root resorption and palatal mucosa depression as a radiolucent shadow. After excisional biopsy, the lesion was diagnosed as COF in histopathologic examination. There was no recurrence at a follow-up 10 months.

The myxoma(odontogenic myxoma, myxofibroma) of the jaws is a benign, usually slow-growing infiltrative tumor of connectice tissue. This article describes a case history of the treatment of recurred odontogenic myxofibroma in the maxilla and further discusses the appropriate management of such cases with reference to the literature review. A 55-year-old male patient presented with a gingival swelling in the right side of maxilla. He had history of second time recurred disease. Microscopically, a high cellularity fibrous tumor with fibroblastic cells was observed. Tumor cells were composed of stellate and spindle shaped fibroblasts. Islands of odontogenic epithelium were seen in the specimen. The final diagnosis was made with odontogenic myxofibroma in consideration of twice-time recurrences and histological characteristics. Because of the high likelihood of recurrence, an accurate differential diagnosis of pathology at the time of initial visit is very important in determining treatment options, and immunohistochemical tests may be helpful. Also close following up is required.(155 words)

Myelolipoma is a benign tumor consists of mature adipocyte and hematopoietic elements. Mostly, this tumor locates in adrenal gland and it also can be found in extra-adrenal area. However, intraosseous myelolipoma is extremely rare. The etiology of this tumor is unclear but some hypothesis proposed that altered mesenchymal stem cell functioning and hormonal events act together in the pathogenesis of myelolipoma. With radiographic view, myelolipoma shows similar characteristics of other fat-containing tumors. The histopathologic examination is necessary for the definite diagnosis. This case report includes a patient with intraosseous myelolipoma of maxilla and mandible and literature review about the clinical, histopathologic, and radiologic features of myelolipoma.

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.

Squamous odontogenic tumor (SOT) is a relatively rare, benign, small (rarely > 1.5 cm in diameter), but locally infiltrative and occasionally aggressive odontogenic epithelial lesion that appears to have harmatomous and neoplastic characteristics [1]. SOT is often asymptomatic, although it can present with mildly painful gingival swelling or tooth mobility. Radiographically, SOT is usually visualized as an irregularly or triangularly shaped unilocular radiolucency associated with the lateral roots of teeth. We report a case of the squamous odontogenic tumor occurring in a 60-year-old female in the right posterior maxilla with unusual radiographic and clinical appearances.

Aneurysmal bone cyst (ABC) in maxilla is a rare and benign lesion but shows extensive bony destruction, occasionally accompanied with secondary osseous lesions, i.e., central giant cell granuloma, ossifying fibroma, fibrous dysplasia, etc. As the pathogenesis of ABC has not been clearly defined, ABC is diagnostically challenged due to its variable histological features. A 17-year-old boy showed a huge radiolucent lesion at right anterior maxilla, which was accidentally found in routine dental-radiological examination for orthodontic treatment. He had no medical history of systemic disease, and did not remember any traumatic experience on his right anterior maxilla. The radiolucent lesion involved periapical area from right central incisor to right first premolar, and was clinically diagnosed as odontogenic keratocyst. During surgical operation a cyst-like sac was enucleated with severe hemorrhage. In the histological observation the thick fibrous sac showed no lining epithelium, and its luminal side disclosed multiple aneurysmal spaces which were shrunken and almost obliterated. The fibrous sac itself was hyperplastic with abundant vascular channels, and produced fibromatous thickening associated with ossifying trabecular bones. This fibro-osseous tissue was hamartomatous, which was not directly connected and organized with marrow bone of maxilla. Finally, the present case was diagnosed as secondary type ABC differentially from traumatic bone cyst (TBC), odontogenic cyst, and central reparative granuloma. And it was presumed that the hamartomatous proliferation of fibro-osseous tissue in the cystic sac of ABC could produce the swelling pressure effect in the bone marrow similar to the overgrowth of central giant cell granuloma, ossifying fibroma, fibrous dysplasia, etc., in the secondary type ABC.

The trauma of incisive canal associated dental implant placement in the anterior maxilla can cause the nasopalatine duct cyst. It is difficult to identify the nasopalatine duct cyst or the location of the incisive canal, only using periapical radiograph or panorama radiograph. So it is necessary to take computed tomography scan for an analysis on the relation between the implant and the incisive canal. This case report present the patient had the nasopalatine duct cyst following the placement of dental implant in the anterior maxilla, and was undergone implant removal and cyst enucleation with bone graft.

Mucormycosis generally presents as an acute infection manifesting in rhinocerebral, pulmonary, gastrointestinal, cutaneous, or disseminated forms. Fungal invasion to the arteries can reduce blood supply by thrombi formation inside the blood vessels, leading to necrosis. Fungal infection usually initiates in the upper turbinate, paranasal sinus, or less commonly in the palate or pharynx. Here we report an unusual case of mucormycosis in the maxilla of a 75-year-old man and present a review of the literature.

Calcifying cystic odontogenic tumor (CCOT), also known as calcifying odontogenic cyst or Gorin cyst is a rare developmental lesion which arises from odontogenic epithelium. It has been classified as a benign odontogenic neoplasm related to odontogenic apparatus by the World Health Organization. CCOT may be associated with other odontogenic tumors, most frequently odontoma, a finding that is a rare event in other types of odontogenic cysts or tumors. This report describes a case of hybrid odontogenic tumor composed of CCOT and ameloblastic fibroma-odontoma of the impacted right maxillary canine region that occurred in a 14-year-old female.

Osteoblastoma is a very rare disease and in case of the jaw, maxilla infrequently occurs more than mandible. On account of difficulty to discriminate from other benign tumor or sarcoma, we need to pay attention to make differential diagnosis based on clinical, radiographic, pathological findings. A tumor on the maxilla and maxillary sinus could lead to a bad result for aesthetic appreciation and function. Therefore, reconstruction after maxillectomy is one of the most important issues concerning a surgery. The aim of this study is to report a case of osteoblastoma on the left maxilla which was misdiagnosed as ossifying fibroma and was treated with hemimaxillectomy and reconstruction using deep iliac circumflex artery musculo-osseous flap which resulted in satisfactory result.

Ameloblastic fibro-odontoma has been defined as a lesion similar to ameloblastic fibroma by WHO, as it shows inductive changes which forms enamel and dentin. Ameloblastic fibro-odontoma is a very rare mixed dentition tumor in children, and the symptom shows indolent edema in maxillary and mandibular molar area. The prevalence is two times higher in male than in female, and two times higher in maxilla than in mandible. Radiologically, it shows clear border and characteristics of both fibroma and odontoma histologically. This review reports a case that a 4-year old female visited in dental clinic of this school for edema as chief complaint in Feb, 2012. Emergency surgical curettage was performed right after initial diagnosis as odontoma, then confirmed diagnosis as Ameloblastic fibro- odontoma after biopsy. Currently, after 6 month, no sign of recurrence can be seen. Ameloblastic fibro-odontoma is very rare mixed dentition tumor. Moreover, as it is the case of female maxilla, this case is worth of publishing. Furthermore, accurate diagnosis of Ameloblastic fibro-odontoma is difficult. This review is published for accurate diagnosis through differential diagnosis of several important mixed dentition tumors.

A 17-year-old male patient was referred for the extraction of impacted mesiodens and canine (#23) before orthodontic treatment. In the radiologic examination, an ovoid-shape radiolucent lesion was found with well-defined hyperostotic rim involved the teeth in left maxillary area. After biopsy examination the lesion was diagnosed as glandular odontogenic cyst (GOC) differentially from non-odontogrnic cysts, i.e., nasopalatine duct cyst. In the immunohistochemistry the cyst epithelium was freguently positive for PCNA, clearly positive for amtloblastin, slightly positive for β-catenin, but rarely positive for amelogenin and cytokeratin 7. Mucin and PRP were positive in the secretory cells of the cyst epithelium. On the other hand, TNFα was strongly positive in the macropahges infiltrated into the mucin-filled cyst lumen, and CD68 and CD31 were positive in the mucin-filled macropahges. These findings may indicate that the glandular elements are derived from hamartomatous secretory organ and that this odontogenic cyst is arisen from the embryonal rests of enamel epithelium, which has a potential to be differentiated into not only the enamel organ but also the secretory gland. Taken together, we assumed that the present case of GOC was originated from the odontogenic epithelium of impacted teeth, but showed the cytodifferentiation of glandular cells.

Plasma cell myeloma is malignant disease of plasma cell in the bone marrow. Myeloma accounts for about 1% of all cancers. The solitary plasma cellmyeloma is rare tumors and account for less than 10% of plasma cell neoplasm. It is often progress to multiple myeloma at 30~40% despite successful local treatment with surgery and radiation therapy. We are reporting a case of solitary plasma cell myeloma on anterior Maxillary region that developed after kidney transplantation and immunosuppressive therapy.