MAML2-Rearranged Mucoepidermoid Carcinoma of the Parotid Gland: A Report in a 20-Month-Old Toddler.

Malignancies of salivary gland origin are rare in children. Mucoepidermoid carcinoma (MEC) is the most common histologic type of salivary gland neoplasm in pediatrics. We report a rare case of parotid MEC in a 20-month-old female patient. The tumor was composed of nests of epidermoid cells with nuclei appearing vesicular, pleomorphic, and hyperchromatic with an admixture of mucous cells and cystic spaces within a prominent connective tissue stroma. Immunohistochemically, the epidermoid cells showed cytokeratin 7 and P63 positivity, and mucous cells were positive for mucicarmine. Molecularly, this case was positive for MAML2 rearrangement by FISH. To our knowledge, this is one of the youngest cases of MEC of the parotid gland reported in the English literature.

Concordance between clinical and histopathologic diagnosis and an audit of oral histopathology service at a Nigerian tertiary hospital.

INTRODUCTION: Although histopathological diagnosis remains the gold standard; good clinical impression is potentially a key diagnostic tool in rural resource-limited settings. Thus, good concordance between clinical impression and histopathological diagnosis is thus a very crucial diagnostic oral pathology tool in low- and middle-income countries (LMICs). METHODS: This retrospective study was performed at the Oral pathology and Oral diagnoses units of Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Osun state. Clinicopathological reports of all biopsies between the period of 2008-2017 were retrieved and analyzed. Descriptive analysis of data was done using Stata 14. Frequency of oral lesions and rates of accurate clinical diagnoses were evaluated for lesional sites and clinician's qualification/specialization. RESULTS: In 592 biopsied cases, the mean age was 36.1years with higher female predilection (54.4%). Odontogenic tumors (OTs) were the most prevalent category of lesions (25.3%, n=149), followed by reactive lesions (12%, n=71). Absolute concordance was recorded for 54.6% (k=0.5) of the cases; with highest concordance observed in fibro-osseous lesions (65.6%, k=0.43), and least in pulp/periapical lesions (3.5%). Concordance was higher in females (59.5%, k=0.53) than males (48.3%, k=0.44). Oral medicine specialists had the highest concordance index (62.5%, k=0.59). CONCLUSION: The findings in this research indicate that, on a general note, the degree of concordance between clinical and histopathological diagnosis is poor. Hence, improvement in diagnostic skills (irrespective of clinical specialty) is important to improve treatment outcomes, particularly in LMICs. Continuous personnel training and utilization of advanced diagnostic techniques can potentially help bridge the diagnostic gaps.

Pattern of distribution of reactive localised hyperplasia of the oral cavity in patients at a tertiary health institution in Nigeria.

BACKGROUND: Reactive localized hyperplastic lesions of the oral cavity (RHLs) are relatively common peripheral lesions which present as a range of clinically similar lesions at dental centers. Diagnosis can be challenging if dentists are unfamiliar with their clinicopathological across various populations. OBJECTIVE: This study reviews the pattern of distribution of RHLs of the oral mucosa in a hospital- the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife. MATERIALS AND METHODS: We reviewed 10 years data from the archives of the Department of Oral Maxillofacial Surgery and Oral Pathology, Obafemi Awolowo University, Nigeria. Information on RHLs were extracted and recorded on standardized data forms and analyzed using STATA. RESULTS: The most common lesions were pyogenic granuloma (43.7%) and focal fibrous hyperplasia (39.7%), respectively. RHLs were found to be more frequent in women (66.7%) than men (33.3%). The most common locations of involvement was the gingivae (84.6%), and lesions were more common in the 9-29 year age group and the mean age was 37.7 (±21.1) years. The relationship between age group and reactive lesions was however not statistically significant. CONCLUSION: The major benefit of this study is an improved knowledge of the frequency and distribution of oral reactive lesions in sub-Saharan Africa which may be highly beneficial when establishing a diagnosis and treatment plan in clinical practice.

A multi-centre evaluation of malignant odontogenic tumours in Nigeria.

INTRODUCTION: odontogenic tumors originate from neoplastic transformation of the remnants of tooth forming apparatus. There are varying degrees of inductive interactions between odontogenic ectomesenchyme and epithelium during odontogenesis, leading to lesions that vary from benign to malignant. Malignant odontogenic tumours (MOTs) are very rare and are classified according to embryonic tissue of origin. Recently, there has been a few changes to the classification of MOTs according to the World Health Organization's (WHO) classification in 2017. This study aims to evaluate and reclassify MOTs, using a multi-centre approach in some major tertiary dental hospitals in Nigeria. METHODS: this study reviewed the clinicopathological data on 63 cases of MOT diagnosed over 25 years in five major tertiary dental hospitals in Nigeria. All MOT cases were reclassified according to the recent revision to the 2017 WHO classification of odontogenic tumours. RESULTS: from a total of 10,446 biopsies of oral and jaw lesions seen at the 5 study centres over the 25-year study period, 2199 (21.05%) cases were found to be odontogenic tumours (OTs), of which 63 were MOT. MOTs constituted 0.60% of the total biopsy cases and 2.86% of OTs. Odontogenic carcinomas presented with a mean age higher than odontogenic sarcomas. According to our 2017 WHO reclassification of MOTs, odontogenic carcinomas, ameloblastic carcinomas and primary intraosseous carcinomas were found to be the top three lesions, respectively. Carcinosarcomas were found to be extremely rare. CONCLUSION: using a multi-centre approach is a robust way to reduce diagnostic challenges associated with rare maxillofacial lesions such as MOTs.

Ameloblastic carcinoma: a clinicopathologic analysis of cases seen in a Nigerian Teaching Hospital and review of literature.

INTRODUCTION: Ameloblastic carcinoma is a rare malignant odontogenic neoplasm that exhibits histological features of ameloblastoma in combination with cytological atypia. It may arise de novo or secondarily through malignant de-differentiation of pre-existing ameloblastoma or odontogenic cyst. Secondary ameloblastic carcinomas often results from repeated surgical intervention, which is a mainstay of odontogenic tumor management in resource limited settings. To date, relatively few cases of ameloblastic carcinomas have been reported and many cases have been misdiagnosed as ameloblastoma. This is due to its wide range of clinicopathological feature which range from indolent to aggressive. It may present as an aggressive ulcerated mass or as a simple cystic lesion; hence, it often challenging to delineate from its benign counterpart, ameloblastoma. METHODS: this study reviewed the clinicopathological data on 157 cases of odontogenic tumors diagnosed over a 10 years period from the pathology archive of the Oral Pathology Unit of Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria. RESULTS: of all these cases, we identified that 64.9% were Ameloblastomas, while 8.3% were ameloblastic carcinomas. Primary subtypes of ameloblastic carcinoma constituted 23.08%, while 69.23% of the cases were of the secondary subtype. We also found that the secondary subtype of ameloblastic carcinomas showed a higher mean duration value of 7.7 years. Most lesions were found in posterior mandible and presented with ulceration, perforation and ill-defined borders radiographically. CONCLUSION: this study is among the few that have documented higher frequency of secondary ameloblastic carcinoma in the scientific literature.