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.

Analysis of Elastic Tissue in Histological Variants of Pleomorphic Salivary Adenoma seen at the Lagos University Teaching Hospital over a period of 35 Years.

BACKGROUND: Pleomorphic salivary adenoma (PSA), is known for its morphologic diversity. While reports of elastic tissue in PSA have been documented, the distribution of this tissue in histological variants of the tumour has not been documented. Perhaps such features may influence biological behaviour of these variants. OBJECTIVE: To classify PSA in our series into histological variants, and determine possible variation in elastic tissue distribution in them. METHODS: Eighty eight histologically diagnosed cases of PSA in the oral biopsy archives of the department of Oral Biology and Pathology, Lagos University Teaching Hospital, were retrieved. New H&E sections were cut to reconfirm diagnosis and Verhoeff-Van Gieson's stained sections were cut for demonstration of elastic tissue. Seifert et al.'s (1976) histological classification was applied and elastic tissue presence was determined and quantified for each case. Parameters studied included; sex, age, site, histological subtypes and presence of elastic tissue. Statistical analysis was undertaken using the EPI-INFO version 3.4. RESULTS: Male:female ratio was 1:1.3. Most cases (63.6%) occurred in the age group of 21-40 years. Generally, palate (42.0%) was the most commonly affected site, while 53.4% of cases were in the minor salivary glands. Seifert et al. classified subtype II lesions were the most frequently observed (39.7%) and elastic tissue was confirmed in 91.0% of cases. No association was noted between proportion of elastic tissue and histological variants. CONCLUSION: Seifert et al subtype II was the most frequently observed and no association was observed between proportion of elastic tissue and the histological variant of PSA.

Clinicohistopathological analysis of 5 Nigerian cases of malignant fibrous histiocytoma of the jaws.

BACKGROUND: Malignant fibrous histiocytoma (MFH), is a soft tissue sarcoma that occurs predominantly in the soft tissue of the extremities. It rarely occurs in facial bones. Few cases in the jaws have been reported. OBJECTIVE: To report and review the relevant clinicopathologic features of 5 cases of jaw MFHin Nigerians. METHODS: All cases in the records of the Department of Oral Pathology of the Lagos University Teaching Hospital which were histologically diagnosed as MFH were retrieved. Hematoxylin and eosin slides of cases were re-examined to confirm diagnosis. Information retrieved included age, sex, location, x-ray, estimated duration, recurrence, and histological presentation. Data was analyzed using SPSS statistical package. RESULTS: Age ranged between 12-42 years with a male sex predilection (3 cases/60.0%) and sole maxillary site predilection (5 cases/100.0%). Estimated duration of lesion ranged from 2 -12 months. Two cases recurred post surgical treatment. All cases presented as the storiform-pleomorphic type with one case presenting with a delicate/scanty connective tissue stroma. Chronic inflammation was scanty in the two cases that recurred. CONCLUSION: MFH of the jaws is rare among Nigerians. Its clinico radiological presentation maymimick other more aggressive or less benign lesions of the jaws thereby resulting in misdiagnosis and in appropriate patient management.

The sensitivity, specificity and accuracy of fine needle aspirational cytology in the diagnosis of oro-facial neoplasms at Lagos University Teaching Hospital, Nigeria.

OBJECTIVE: The aim of the study is to compare the efficacy of fine needle aspirational cytology (FNAC) with open surgical biopsy in the diagnosis of orofacial tumours in patients seen at the Dental Centre of Lagos University Teaching Hospital from May 2005-May 2006. PATIENTS AND METHODS: Fine needle aspiration was performed on all patients scheduled for open surgical biopsy at the Oral and Maxillofacial clinic of the hospital before the open surgical biopsy was done. Forty six patients whose final histological diagnoses were oro-facial neoplasms were involved in this study. Sensitivity, specificity and accuracy for fine needle aspirational cytology were calculated. RESULTS: The sensitivity, specificity and accuracy of fine needle aspirational cytology in the diagnosis of oro-facial tumours were 95%, 95.8% and 95.5%, respectively. The false positive and false negative rates were 5% and 4.2%, respectively. CONCLUSION: The high sensitivity, specificity and accuracy of fine needle aspirational cytology reported in this preliminary study suggest that the test may have a place in the management of oro-facial tumours. However, when the result of fine needle aspirational cytology is not in agreement with the clinical diagnosis, especially in suspected malignancy, open surgical biopsy should be performed.

Argyrophilic nucleolar organiser region (AgNOR) study of some odontogenic cyst epithelium.

AIMS AND OBJECTIVES: This study compared the biologic activity of three different cyst types and assessed the value of the AgNOR technique as an aid to diagnosis. BACKGROUND: The nucleolar organiser region (NORs) reflect replicatory activities within the cells. It has been found to be of diagnostic value in the prediction of the biologic behaviour of some tumors and even oral epithelial dysplasia. MATERIALS AND METHODS: Thirty histologically diagnosed H & E sections of cystic lesions consisting of ten (10) radicular, ten (10 dentigerous and ten (10) odontogenic kerotocysts were randomly selected from the record of biopsy services of the Lagos University Teaching Hospital. The paraffin blocks of the selected sections were retrieved for AgNOR staining. For each cyst type the mean and standard deviation of AgNORs/100 cells was calculated and compared with other cyst types using an analysis of variance and student's t-tests. RESULTS: RESULTS of this study show a statistically significant higher means AgNORs cyst. (p = 0.0016; p = 0.00049 and respectively). However, no statistically significant difference in mean AgNOR score/cell was found when the radicular and dentigerous cysts were compared. CONCLUSION: These variations reflect the difference in the proliferation rate of the odontogenic keratocyst, radicular and dentigerous cysts.

Pregnancy epulis associated with life threatening haemorrhage in a Nigerian woman.

Pregnancy tumour is a clinical term used to identify a pyogenic granuloma that occurs in pregnant women. Pregnancy tumour is not uncommon, but severe bleeding associated with the lesion necessitating blood transfusion is rare. We report a rare case of mandibular gingival pregnancy tumour with a life-threatening haemorrhage in a 25-year-old Nigerian woman. The patient had lost an estimated 2 litres of blood before presentation. Her packed cell volume was 8% at presentation. The patient was managed by infusion of fluid, transfusion of 4 units of blood and ligation of the facial artery; and excision of the lesion. Following an uneventful healing, she was discharged 10 days later with a PCV of 40.5%. Following subsequent review there was a recurrence 2 months later that regress after 1 month. She was subsequently lost to further follow up.

Tumours of the submandibular salivary gland: a clinicopathologic review of cases over a 17-year period.

OBJECTIVE: This study presents a clinicopathologic review of cases of submandibular salivary gland tumours at the Lagos University Teaching Hospital, Nigeria, over a period of 17 years. METHODS: The records of all patients with histological diagnosis of submandibular salivary gland tumours at the Lagos University Teaching Hospital over a period of 17 years (January 1990 to December 2006) were retrospectively reviewed. Parameters studied were; age and gender of patients, symptoms and duration of symptoms, and histological diagnosis. RESULTS: A total of 36 patients with submandibular gland tumours were seen during the period. Male-to-female ratio was 1.8:1 (male=23, female=13). Mean age (+/- SD) at presentation was 43 (+/- 19) years (age range, 17-84 years). There were 19 malignant tumours and 17 benign ones. Pleomorphic adenoma (36.1%) was the most frequent tumours, followed by adenoid cystic carcinoma (11.1%), anaplastic carcinoma (11.1%) and malignant lymphoma (11.1%). Patients with histological diagnosis of malignant tumours were significantly older than those with benign tumours (p = 0.01). Most patients (80.6%) presented with painless swelling. CONCLUSION: Malignant submandibular salivary gland tumours were slightly more than the benign ones in the studied population. Painful swelling or ulceration is indicative of a malignant submandibular gland tumour

Primary malignant neoplasms of orofacial origin: a retrospective review of 256 cases in a Nigerian tertiary hospital.

A retrospective review of cases histologically diagnosed as malignant lesions of the orofacial region in 1992-2003 from the records of the Department of Oral Pathology and Biology, Lagos University Teaching Hospital, Nigeria was carried out. All cases were subjected to analysis of age, gender, site distribution and histologic types. Malignant tumours constituted 18% of all the biopsies of orofacial lesions seen within the period. The mean age of patients was 42.2+/-21.5 years (range: 2.5-85). There were 177 (69%) epithelial tumours of which squamous cell carcinoma was predominant, 47 (18%) sarcomas and 32 (13%) lymphomas. Squamous cell carcinoma (44%) was the most common malignant orofacial tumour. Osteosarcoma (32%) and Burkitt's lymphoma (56%) was the predominant sarcoma and lymphoma, respectively. Patients with a histologic diagnosis of carcinoma were older than those with sarcomas and lymphomas (P<0.01), and those with a histologic diagnosis of malignant lymphoma were significantly younger than those with sarcomas (P<0.01). Almost 25% of patients with carcinomas were below the age of 40 years. Malignant orofacial tumours are not uncommon in the studied environment, with a sizable proportion of carcinomas occurring before the age of 40 years.

Salivary gland tumours: a 15-year review at the Dental Centre Lagos University Teaching Hospital.

The aim of this study was to determine the relative frequency of tumours of the salivary gland seen at the Dental Centre, Lagos University Teaching Hospital, Nigeria over a period of 15 years. All cases that were histologically diagnosed as salivary gland tumours from January 1990 to December 2004 were retrieved from the histopathology records of the Department of Oral Pathology and Biology and Department of Oral and Maxillofacial Surgery of the Lagos University Teaching Hospital, Lagos, Nigeria. All the cases were subjected to analysis of age, sex, site of occurrence and histologic diagnosis based on 1991 World Health Organisation (WHO) classification. Salivary gland constituted 6.3% of all oro-facial tumours and tumour-like lesions. The frequency of malignant tumours was 60.8% (n = 73) and benign tumours 39.2% (n = 47). Minor salivary glands (63.3%) were mostly affected. The male-to-female ratio was 1.1:1, and most (72.5%) of the tumours occurred in the age group of 21-60 years. Pleomorphic adenoma was the most commonly occurring tumour (29.2%) followed by adenoid cystic carcinoma (19.2%). The predominant benign and malignant tumours were pleomorphic adenoma and adenoid cystic carcinoma respectively. Palate (45.8%) was the most frequently affected site. The mean.age (+/-SD) of patients with benign tumours was significantly lower than those with malignant tumours (P = 0.003). The incidence of salivary gland tumours in this study is higher than in most previous reports. Malignant tumours which occurred in older age group were the most commonly seen.

Malignant orofacial neoplasms in Lagos, Nigeria.

OBJECTIVES: To analyse general differences in age, gender, anatomic location of the various histological types of malignant neoplasm involving the oral and maxillofacial region at a tertiary referral centre in Nigeria and to compare this with reports in the literature. DESIGN: Retrospective analysis. SETTING: A tertiary referral centre in Lagos, Nigeria. SUBJECTS: All patients with a histological diagnosis of malignancy were included provided the final surgical histology reports as well as the biopsy reports were available for review. RESULTS: Squamous cell carcinoma (SCCA) with a peak age incidence in the 6th decade of life and a male to female ratio of 1.65 to 1 was the most common cancer (42.8%). Males with SCCA (mean = 48.7 years) were relatively younger than females (mean = 58.8 years). Eighteen percent of patients with SCCA were below 40 years at presentation and males were predominantly affected at a ratio of 5.2:1. Majority of the SCCA (75%) were well/moderately well differentiated. However, in patients below 40 years, 45.9% had poorly differentiated SCCA. The Most commonly affected sites for SCCA were the maxillary antrum (36.7%), mandibular gingiva/ alveolus (23.0%) and tongue (12.04%). Patients who presented with antral SCCA were relatively younger (mean = 48.9 years) than those who had SCCA involving the mandibular gingiva/ alveolus (mean = 57.1 years) as well as floor of mouth (mean = 56.3 years). Furthermore, males with antral SCCA were younger than their female counterparts. Similarly, males who had mandibular gingiva/ alveolus SCCA (mean = 48.4 years) were younger than their female counterparts (mean = 62.8 years). Majority of the glandular carcinomas (GLDCAs) arose from minor salivary glands (63.0%). Thirty seven per cent of these patients were below 40 years at presentation. Females who had antral GLDCA (mean = 32.4 years) were relatively younger than their male counterparts (mean = 49 years). Most of the patients who presented with sarcoma were below 40 years (77.4%) and males were younger (22. 8 years) than females (mean = 35.4 years). CONCLUSIONS: The proportion of orofacial cancers that is SCCA in Nigerians is relatively low because of a relatively high proportion of GLDCA and Burkitt's lymphoma. A relatively high proportion of patients with SCCA were below 40 years at presentation. They were predominantly males who presented with poorly differentiated tumours.

Surgical management of a large complex odontoma of the mandibular angle-ramus region through intra-oral buccal approach--A case report.

Large complex odontomas of the jaws are rare. A report of a large complex odontoma of the mandibular angle-ramus region enucleated through intra-oral buccal approach is presented. A review of the literature on different modalities of treatment is also undertaken. A large expansile complex odontoma of the angle-ramus region of the mandible was excised through an intraoral buccal approach under general anaesthesia. Recovery and immediate post-operative period were uneventful. There was no altered sensation in the distribution of the inferior alveolar nerve and lingual nerve; and wound healing was satisfactory. Post-operative radiograph 2 years after the operation showed satisfactory bone regeneration. Intraoral buccal approach to large complex odontomas of the angle-ramus region of the mandible is a relatively safe procedure with minimal complication.

Ameloblastoma in Nigerian children and adolescents: a review of 79 cases.

PURPOSE: To descriptively review the clinicopathologic presentation and management of ameloblastoma in Nigerian children and adolescents and compare this with previous reports in the literature. METHODS AND MATERIALS: Data were collected from the case files of patients managed at 4 tertiary referral centers in Nigeria. RESULTS: Out of a total of 360 patients with a diagnosis of ameloblastoma, 79 were under 20 years of age at presentation (21.9%). Only 2.5% of the patients were under 10 years of age. The male-female ratio was 1.3 to 1 with a peak age incidence of 15 years in males and 17 years in females. All the tumors were intraosseous and the majority (94.9%) were situated in the mandible. The most common morphologic type was solid multicystic ameloblastoma (82.3%). The majority (66.2%) had a multilocular radiographic presentation. In most patients (57.3%), the symphysial region of the mandible was involved by the tumor. However, exclusively anterior tumors constituted only 15.2% of the cases, while tumors involving anterior and posterior jaw regions constituted 41.1%. Resection was the predominant (72.2%) form of surgical management. CONCLUSION: Ameloblastoma in Nigerian children and adolescents exhibit some peculiar clinical features: these include the predominance of males, and of the solid multicystic morphologic type. In addition, there is site predilection for the symphysial region of the mandible. Radical surgical resection remains the predominant form of treatment. Therefore, varying degrees of interference with facial growth will be present in these children.

The adenomatoid odontogenic tumor: an analysis of 57 cases in a black African population.

PURPOSE: This study analyzed the findings in a large series of adenomatoid odontogenic tumors (AOT) in Nigerians. PATIENTS AND METHODS: Hospital records of all cases of AOT diagnosed at three teaching hospitals were reviewed and analyzed. RESULTS: Most of the tumors were intraosseous (central) (98.3%) and of the follicular type (75%). Females were more frequently affected than males (1.4:1), and patients in their second decade of life were most frequently affected (75%). Patients with follicular AOT were relatively younger (15.2 +/- 5.6 years) than those with extrafollicular tumors (20.9 +/- 13.8 years). However, males who presented with extrafollicular tumors (14.6 +/- 3.9 years) were relatively younger than their female counterparts (24.9 +/- 16 years). The maxilla was affected nearly twice as often as the mandible (1.8:1), and the canine tooth was frequently embedded in the tumor (76.9%). Although follicular tumors were most frequently located in the maxilla (76.3%), extrafollicular tumors were more commonly found in the mandible (69.2%). CONCLUSION: The distribution of this tumor in black Africans does not appear to be substantially different from that reported in caucasians.