Principles of Manual Tissue Processing in an Oral and Maxillofacial Pathology Laboratory in Lagos, Nigeria.

INTRODUCTION: Tissue processing describes the steps involved in infiltrating a well fixed tissue with wax for section cutting on a microtome. Paraffin tissue processing can be performed either manually or by using an automated tissue processor and errors in any of the steps involved would significantly affect histopathology. The aim of this article was to describe to principles of manual tissue processing as performed in the Oral and Maxillofacial Pathology Laboratory of the College of Medicine, University of Lagos, Nigeria (OMFP-CMUL Lab). METHODS: We report the principles of manual tissue processing as performed in the OMFP-CMUL lab using the index case of an 11-year-old girl with a histopathologic diagnosis of unicystic ameloblastoma. RESULTS: Steps of tissue processing included fixation, specimen accessioning, gross examination, decalcification (for tissue specimens containing calcium deposits), dehydration, clearing, infiltration, embedding, sectioning, labeling of tissue blocks, tissue floatation bathing, making the slide and numbering, staining, drying, cover-slipping, and microscopic examination. DISCUSSION: Common errors seen in histopathology laboratories were avoided by the quality control practices of the residents, consultants, laboratory scientists and technicians within the department.

INTRODUCTION: Le traitement des tissus décrit les étapes d'infiltration d'un tissu bien fixé avec de la cire pour la coupe de sections sur un microtome. Le traitement des tissus en paraffine peut être effectué soit manuellement ou à l'aide d'un processeur de tissus automatisé et les erreurs commises dans l'une ou l'autre de ces étapes peuvent affecter de manière significative l'histopathologie. Le but de cet article était de décrire les principes du traitement manuel des tissus tel qu'il est effectué dans le laboratoire de pathologie orale et maxillofaciale du Collège de Médecine de l'Université de Lagos, Nigeria (Laboratoire OMFP-CMUL). MÉTHODES: Nous rapportons les principes du traitement manuel des tissus tels qu'ils sont réalisés dans le laboratoire de l'OMFPCMUL en utilisant le cas d'index d'une fille de 11 ans avec une diagnostic histopathologique d'améloblastome unicystique. RÉSULTATS: Les étapes du traitement des tissus comprennent la fixation, l'accession des spécimens, l'examen macroscopique, la décalcification (pour les spécimens de tissue contenant des dépôts de calcium), la déshydratation, le nettoyage, l'infiltration l'enrobage, la coupe, l'étiquetage des blocs de tissus, la flottaison des tissus, le bain, la fabrication de la lame et la numérotation, la coloration, le séchage, le recouvrement et l'examen microscopique. DISCUSSION: Les erreurs courantes observées dans les laboratoires d'histopathologie ont été évitées grâce aux pratiques de contrôle de qualité des résidents, consultants, des scientifiques et des techniciens de laboratoire au sein du service. CONCLUSION: Cet article élucide les principes du traitement manuel des tissus tel qu'il est effectué dans le laboratoire de l'OMFPCMUL en détaillant leurs protocoles observés et les mesures de prévention des erreurs afin que ces principes et mesures puissent être adoptés dans d'autres laboratoires d'histopathologie ayant des conditions de travail similaires. MOTS CLÉS: Manuel, traitement des tissus, laboratoire de pathologie, Lagos, Nigeria.

Descriptive Epidemiology of Odontogenic Tumors in Nigeria: An African Oral Pathology Research Consortium Multicenter Study.

BACKGROUND: Many studies have investigated the burden of odontogenic tumor (OT) in Nigeria; however, the true burden and prevalence of these lesions are not known because these studies are based on a center/region. AIMS: Hence, the aim of this study is to evaluate the true burden of OTs in Nigeria, using a multicenter approach. MATERIALS AND METHODS: This is a 10-year retrospective cross-sectional study of OT seen in eight tertiary health institutions in different geographic locations in Nigeria. RESULTS: A total of 990 cases were included in this study. The highest prevalence of OT was in the third decade of life (n = 274, 27.7%). Most lesions were benign (n = 961, 97.1%), with a slight male preponderance; and the mandible was the commonest site (n = 814, 82.2%). There were a significant association between the diagnosed OTs and the age group and site (P = 0.002 and 0.031, respectively). CONCLUSION: OTs showed a slightly higher preponderance in males, occurring mostly in the third decade. Benign lesions were frequent and ameloblastoma was the commonest OT. Variations exist in the occurrence of OTs from the different geographic locations in Nigeria. This study essentially sheds a broader light on the clinicopathological distribution of OTs across Nigeria, using a large multicenter approach.

Ameloblastoma: current etiopathological concepts and management.

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/ß-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

Use of information and communication technology among dental students and registrars at the faculty of dental sciences, University of Lagos.

The aim of this study was to investigate the use of information technology amongst dental students, dental nursing students and resident doctors in training at the faculty of dental Surgery University of Lagos. A structured questionnaire was distributed to 58 clinical dental students in 4 th and 5 th years of training in the 2010/2011 academic year, 36 dental nursing students and 63 resident doctors undergoing specialist training. All participants have access to the computers, 2.5% within the University and 31% at home and internet cafes and about 50% have the basic skills required. A significant difference was observed between the resident doctors and clinical dental students (P = 0.003), between resident doctors and dental nursing students (P = 0.0001) when the use of computer for study was compared. Over 95% of participants have access to internet and about 50% of them use the internet for their studies. A significant difference (P = 0.005) was observed between clinical dental students and dental nursing students that use the internet and word processing. The resident doctors used the computers for multimedia and MedLine search tools more than clinical dental students (P = 0.004) and dental nursing students (0.0006). The findings of the study show that dental students and resident doctors in training have the requisite knowledge to operate the computer for use in their study and personal activities.