Odontogenic tumours—An update

Odontogenic tumors: analysis of 188 cases from Saudi Arabia

BACKGROUND AND OBJECTIVES

Odontogenic tumors (OTs) represent an uncommon group of lesions that arise from the tooth-forming apparatus. They pose a significant diagnostic and management challenge. There is a lack of data among the Saudi population. The aim of the study was to establish the relative frequency of the various histological types of OTs.

DESIGN AND SETTINGS

A retrospective study of 188 cases of OTs using the histopathology archives of the College of Dentistry, King Saud University.

METHODS

The histopathology archives of the College of Dentistry, King Saud University were reviewed from January 1984 to December 2010 for OTs. The age and gender of the patients, tumor site, and histopathologic typing were analyzed.

RESULTS

A total of 188 (4.3%) patients met the criteria for being classified as an OT. Odontogenic keratocystic tumor (36.7%) was the most commonly diagnosed, followed by ameloblastoma (25.0%), odontoma (14.9%), and odontogenic myxoma (6.4%). Two cases of malignant OTs (1.1%) are found. The male-to-female ratio was 1.4:1. The most frequently affected area was the posterior mandible (48.9%), followed by the anterior maxilla (22.9%).

CONCLUSION

This is a relatively large series of OTs revealing aspects of similarities and differences with those of previous studies of populations in Africa, Asia, and the Americas. The findings of the present study may be useful as a guide for clinicians who need to make clinical judgments prior to biopsy about the most probable diagnosis.

Bilateral Calcifying Odontogenic Cyst: A Rare Entity

The calcifying odontogenic cyst (COC) accounts for 1 % of jaw cysts, found most commonly as central lesion. The COC usually manifests itself as a painless, slow growing swelling, anterior to the first molar region. Radiographically it appears as a well-defined, unilocular radiolucency, and may have a radiopaque mass in its center. Majority of the cases appear before the fourth decade of life. The COC is found rarely in patients in the first decade of life. Histopathological features include a cystic lining demonstrating characteristic "Ghost" epithelial cells with a propensity to calcify. Here we report the unusual occurrence of a case of 8 year child diagnosed with bilateral COC on right and left side of mandible.

Sequestrating giant complex odontoma: a case report and review of the literature

Odontomas are the most common benign tumours of odontogenic origin. Due to their hamartomatous nature, they are usually asymptomatic but can cause impaction of one or more teeth. They consist microscopically of all the tissue types found in a developed tooth. We present a case of a large sequestrating complex odontoma resulting in facial asymmetry, cellulitis, pain and partial loss of function. This case has significance, as odontomas of this large size have rarely been reported.

Sclerosing odontogenic carcinoma in the maxilla: a rare primary intraosseous carcinoma

Sclerosing Odontogenic Carcinoma (SOC) was first described by Koutlas et al. in 2008. SOC is a low-grade odontogenic carcinoma, which presents as an expansile radiolucency that causes tooth displacement and root resorption. It is locally aggressive but reports suggest a very low probability of regional or distant metastasis. SOC contains small nests and thin cords of small cuboidal or polygonal epithelial cells with cytoplasmic clearing. Pleomorphism and mitoses are not prominent. Skeletal muscle and perineural infiltration with stromal sclerosis is characteristic. Immunohistochemically, SOC stains for cytokeratins (CK) 5/6 and 19, and e-cadherin. Nuclear staining with p63 is also positive. CK20, carcinoembryonic antigen and CAM 5.2 are negative. We report a rare entity of primary intraosseous carcinoma of the maxilla which has the clinical and histological markers of SOC. Occurrence in the maxilla has been reported only once before in the literature.

Maxillary ameloblastoma mimicking an oroantral fistula

BACKGROUND

The aim of this current report is to present an unusual case of a maxillary ameloblastoma mimicking an oroantral fistula.

CASE REPORT

A left subtotal maxillectomy via Weber-Ferguson-type incision was performed. The patient tolerated the procedure well, the postoperative course was uneventful, and the patient was discharged 3 days after surgery with a mild paraesthesia of the right infraorbital nerve distribution. The infraorbital nerve paraesthesia has resolved 5 months after resection. The patient has been followed-up for 3 years without recurrence.

DISCUSSION

Ameloblastoma is a well-known pathology of the maxillofacial region. However, unusual manifestations of this tumor can represent a serious challenge for diagnosis.

Locally infiltrative ameloblastic fibroma in a rhesus macaque (Macaca mulatta) with characterizations of its proliferating activity and biological behavior

An 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocular radiolucent mass with abundant osteolysis. The mass was grossly firm, fleshy, and gelatinous on the cut surface. Histologically, the mass was locally infiltrative and composed of neoplastic epithelial and mesenchymal components that stained positive for cytokeratin and vimentin, respectively. Occasional densely spherical condensations of fibroblasts resembling the cap stage of odontogenesis were present in the mesenchyma. Immunohistochemical staining with Ki-67, S-100, and CD34 indicated that both epithelial and mesenchymal components of the neoplasm had low proliferation. Alcian blue, periodic acid-Schiff, and trichrome stains showed an immature stromal component with no collagen formation. Based on the clinical, histologic, and immunophenotypic features, the tumor was identified as a locally infiltrative ameloblastic fibroma.

Cell proliferation and apoptosis in ameloblastomas and keratocystic odontogenic tumors

A high proliferative activity of the odontogenic epithelium in ameloblastoma (AM) and keratocystic odontogenic tumor (KOT) has been demonstrated. However, no previous study has simultaneously evaluated cell proliferation and apoptotic indexes in AM and KOT, comparing both lesions. The aim of this study was to assess and compare cell proliferation and apoptotic rates between these two tumors. Specimens of 11 solid AM and 11 sporadic KOT were evaluated. The proliferation index (PI) was assessed by immunohistochemical detection of Ki-67 and the apoptotic index (AI) by methyl green-pyronine and in situ DNA nick end-labelling methods. KOT presented a higher PI than AM (p<0.05). No statistically significant difference was found in the AI between AM and KOT. PI and AI were higher in the peripheral cells of AM and respectively in the suprabasal and superficial layers of KOT. In conclusion, KOT showed a higher cell proliferation than AM and the AI was similar between these tumors. These findings reinforce the classification of KOT as an odontogenic tumor and should contribute to its aggressive clinical behavior.

Assessment of computerized tomography density patterns of ameloblastomas and keratocystic odontogenic tumors

The aim of this study was to evaluate computerized tomography (CT) density patterns of solid ameloblastomas (SA), unicystic ameloblastomas (UA), and sporadic and multiple keratocystic odontogenic tumors (SK and MK, respectively). A region of interest (ROI) was delimited corresponding to almost the entire lesional area on each axial slice of 25 CT exams. For each ROI, CT values (HU(ROI)) and heterogeneity (HTG(ROI)) were recorded and compared among lesion groups as well as among central and peripheral slices of the same lesion. The average HU(ROI) were: SA 35.9 +/- 12.6; UA 31.0 +/- 6.0; SK 28.4 +/- 10.5; and MK 30.5 +/- 20.6. SK and MK had the lowest CT values and highest heterogeneity. SA and UA did not show statistical difference for HU(ROI). However, SA had greater HTG(ROI) values. SA presented a different pattern when the central slices were compared with the peripheral slices. HU(ROI) was higher, whereas HTG(ROI) was lower, among the central slices of SA.

Odontogenic tumors of the maxillary sinus

PURPOSE OF REVIEW

To help the clinician understand the different odontogenic tumors found commonly in the maxillary sinus in terms of clinical and radiographic findings, diagnosis and treatment.

RECENT FINDINGS

The classification of odontogenic tumors has changed recently with the addition of the odontogenic keratocyst and calcifying odontogenic cyst (Gorlin cyst) from the realm of odontogenic cysts to being classified by the WHO as odontogenic tumors based upon their neoplastic biologic behavior. The odontogenic keratocyst is now called a keratocystic odontogenic tumor. The calcifying odontogenic cyst is now called a calcifying cystic odontogenic tumor.

SUMMARY

The diagnosis of odontogenic tumors of the maxillary sinus is difficult and challenging. Surgeons need to work in conjunction with an oral and maxillofacial pathologist to ensure accurate diagnosis for proper surgical planning.