Comparative Immunohistochemical Analysis of p53 and Alpha-SMA in Ameloblastoma, AOT and OKC.

OBJECTIVES: Ameloblastoma is a benign but highly infiltrative tumour, a behaviour that is lacking in adenomatoid odontogenic tumour but partly shared by the odontogenic keratocyst which possesses a unique intrinsic growth potential with marked ability for destroying bone and a high tendency recurrence. High frequency of stromal myofibroblasts (assessed with alpha smooth muscle actin (α-SMA) correlates with aggressive behaviour while p53-cell cycle regulation system is critical in odontogenic tumours with immunoreactivity signifying prognostic status. This study aims to determine and compare the immunoreactivity of these selected tumours to p53 and α-SMA in order to establish if a relationship exists between the frequency and pattern of distribution of myofibroblasts and the behaviour of these lesions. MATERIALS AND METHODS: 69 blocks of ameloblastoma, and 23 each of adenomatoid odontogenic tumor (AOT), and odontogenic keratocyst (OKC/KCOT) were retrieved. Immunohistochemistry technique was applied for evaluation of these two markers staining with primary antibodies to p53 and -SMA and the frequency and pattern of distribution of myofibroblasts and immunoreactivity to p53 analysed and compared using ANOVA. p was set at <0.05. RESULTS AND CONCLUSION: Immunoreactivity to p53 and α-SMA was highest in ameloblastoma (solid compared to unicystic) with highest mean positive cells to α-SMA (29.7±20.1) and p53 (28.3±24.5) in plexiform ameloblastoma. This suggests that ameloblastoma was the most aggressive of tumours studied. Different pharmacological agents that can regulate stromal MF are useful aids to decrease the need for radical surgery in extensive and aggressive odontogenic tumours.

ABSTRAIT OBJECTIFS: L'améloblastome est bénin mais untumeur mes infiltratif, un comportement qui fait défaut dans la tumeur odontogénique adénomatoïde mais en partie partagé par le kératocyste odontogène qui possède un potentiel de croissance intrinsèque unique avec une capacité marquée de destructionet une récidive à forte tendance. Haute fréquence de stromalmyofibroblastes (évalués avec de l'actine musculaire alpha lisse (α-SMA) est en corrélation avec un comportement agressif lors de la régulation du cycle des cellules p53 est essentiel dans les tumeurs odontogènes immunoréactives signifiant le statut pronostique. Cette étude vise à déterminer et comparer activité l'immunoré de ces tumeurs sélectionnées à p53 et α-SMA afin d'établir s'il existe une relation entre le fréquence et schéma de distribution des myofibroblastes et de la comportement de ces lésions. MATÉRIAUX ET MÉTHODES: 69 blocs d'améloblastome, et 23 chacun de tumeur odontogénique adénomatoïde (AOT) et odontogènedes kératocystes (OKC/KCOT) ont été récupérés. Immunohistochimiela technique a été appliquée pour l'évaluation de ces deux marqueurs de coloration avec des anticorps primaires dirigés contre p53 et α-SMA et la fréquence et schéma de distribution des myofibroblastes et de l'immunoréactivité àp53 analysé et comparé à l'aide de l'ANOVA. p a été fixé à <0,05. RÉSULTATS ET CONCLUSION: Immuno réactivité à p53 et α-SMA était la plus élevée dans l'améloblastome (solide par rapport α-SMA (29,7±20,1) et p53(28,3±24,5) dans l'améloblastome plexiforme. Cela suggère que L'améloblastome était la tumeur la plus agressive étudiée. Les agents pharmacologiques différentes peuvent réguler la MF stromale sont des aides utiles pour diminuer le besoin de chirurgie radicale en cas de chirurgie étendue et agressive tumeurs odontogènes. Mots-clés: Améloblastome, AOT, OKC/KCOT, p53, α-SMA, myofibroblastes, tumeurs odontogènes, immunoréactivité.

Neoplastic Salivary Gland Lesions:A Retrospective Analysis of 135 Cases from Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria.

BACKGROUND: Although a variety of etiological factors have been implicated in some salivary gland tumours, most salivary gland neoplasms are idiopathic making it difficult to explain the striking epidemiological differences in their global distribution. OBJECTIVE: This study was carried out to determine the prevalence and the distribution pattern of salivary gland neoplasia in Lagos State University Teaching Hospital, Ikeja, Lagos and to provide data for comparison with other epidemiological findings in different geographic locations. METHODS: This was a retrospective study of cases of neoplastic salivary gland lesions seen from 2001 to 2012. 135 cases were extracted from pathology records and data on incidence, age, gender, site and histological diagnosis of the various tumours were analyzed using descriptive statistics. RESULTS: Benign lesions accounted for 77 (57%) cases while only 58 (43%) cases were malignant. Fifty-eight (43%) were found in males while seventy-seven (57%) occurred in females giving a male-to-female ratio of 1:1.3. The mean age at diagnosis (+SD) was 41.1+16.7 (range 5-83 years) and the peak incidence was in the 5th decade of life (32 cases, 23.7%). Seventy-seven (57%) were benign while fifty-eight (43%) were malignant. The palate was the most common site accounting for forty-five (33.3%) cases. Pleomorphic adenoma (PA) was the most common salivary gland tumour reported accounting for sixty-seven (49.6%) cases. This is followed by adenoid cystic carcinoma (ACC) (27 cases, 20%). CONCLUSIONS: We reported PA as the commonest benign salivary gland tumour. Contrary to many other Nigerian studies, our series revealed that ACC is the commonest malignant salivary gland tumour. This may be due to misdiagnosis of cases of ACC as other histologically similar lesions in other centres. Contrary to reports in many other studies where the parotid accounts for the commonest site, the palate was the commonest in our series.

Odontogenic and oral soft tissue myxomas: clinicopathologic analysis of 16 cases from Ile-Ife, Nigeria.

OBJECTIVES: Odontogenic myxomas (OMs) are considered slow-growing tumours with the potential for extensive bone destruction, cortical expansion, and a relatively high recurrence rate. We analysed the cases histologically diagnosed as OM in our centre and compared these to the data found in the literature. METHOD: A record-based study of OMs histologically diagnosed at the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Southwest Nigeria between 1990 and 2009 was conducted. The tumours were classified as myxomas, fibromyxomas or myxofibromas depending on the histologic picture. Gingival masses with similar histologic features but not showing bone involvement were included in the series as soft tissue myxomas. RESULTS: A total of 16 histologically diagnosed cases were recorded, 11(68.8%) in females and 5 (31.2%) in males giving a male:female ratio of 1:2.2. The most common tumour site was the maxilla (7 cases, 43.8%) and the mean age of the patients at the time of diagnosis was 31.1+/-18.0 years. Myxomas, exhibiting complete myxomatous tissue (8 cases, 50%) with no appreciable fibrous component were the most common histological type. CONCLUSION: The peak incidence was in the 2nd decade of life and there was a predilection for females (M:F = 1:2.2) and the maxilla. The recommended treatment of choice is radical surgery or conservative excision depending on tumour size.

Osteolipoma of the palate: report of a case and review of the literature.

Oral lipomas, though rare, predominantly affect the buccal mucosa, tongue, and lips. The occurrence of lipomas in the palate is extremely rare. Osteolipoma is a very rare histological variant of lipoma accounting for less than 1% of all cases. Although a few cases involving the soft palate have been reported, there is only one reported case of osteolipoma of the hard palate in the English-language literature and it was a congenital osteolipoma associated with a cleft palate in a 6-year-old male child. This paper aims to describe an additional case uniquely located in the hard palate of an adult female.

Ectodermal odontogenic tumours: analysis of 197 Nigerian cases.

This article presents a clinico-pathologic analysis of 197 cases of ectodermal odontogenic tumours archived in the Lagos University Teaching Hospital, Lagos Nigeria over a 21-year period. They were categorized according to the WHO classification of odontogenic tumours. Of the 197 cases, 182 (92.3%) were benign while 15 (7.6%) were malignant. Central ameloblastoma, which accounted for 88.3% in this series, was the most common benign neoplasm demonstrating predilection for males (58.6%) and the mandible (83.3%). The mean age of occurrence (+/-SD) was 31.00 +/- 13.9 (range 9-82 years). Similarly ameloblastic carcinoma was the most prevalent malignant tumour (5.6%) with a predilection for females (63.6%) and the mandible (81.8%). The mean age of occurrence (+/-SD) was 30.1+/- 20.7 (range 16-85) years. Follicular ameloblastoma was found to be the commonest histologic subtype seen in Nigeria.

Ameloblastic carcinoma of the jaws. A report of three Nigerian cases.

Ameloblastic carcinoma is an exceptionally rare and aggressive orofacial neoplasm that belongs to a family of malignant epithelial odontogenic tumours. The aetiology remains largely unknown, however most cases are presumed to have arisen de novo, with few of them presenting following malignant transformation of ameloblastoma. We report our experience with three rare cases of ameloblastic carcinoma seen in Nigerians. This is an addition to the sparse literature and to our knowledge; there has been no such report from sub-Saharan Africa.