Appraisal of jaw swellings in a Nigerian tertiary healthcare facility

Contrast-enhanced multidetector computed tomography features and histogram analysis can differentiate ameloblastomas from central giant cell granulomas

BACKGROUND

No qualitative or quantitative analysis of contrast-enhanced computed tomography (CT) images has been reported for the differentiation between ameloblastomas and central giant cell granulomas (CGCGs).

AIM

To describe differentiating multidetector CT (MDCT) features in CGCGs and ameloblastomas and to compare differences in enhancement of these lesions qualitatively and using histogram analysis.

METHODS

MDCT of CGCGs and ameloblastomas was retrospectively reviewed to evaluate qualitative imaging descriptors. Histogram analysis was used to compare the extent of enhancement of the soft tissue. Fisher’s exact tests and Mann–Whitney U test were used for statistical analysis (P < 0.05).

RESULTS

Twelve CGCGs and 33 ameloblastomas were reviewed. Ameloblastomas had a predilection for the posterior mandible with none of the CGCGs involving the angle. CGCGs were multilocular (58.3%), with a mixed lytic sclerotic appearance (75%). Soft tissue component was present in 91% of CGCGs, which showed hyperenhancement (compared to surrounding muscles) in 50% of cases, while the remaining showed isoenhancement. Matrix mineralization was present in 83.3% of cases. Ameloblastomas presented as a unilocular (66.7%), lytic (60.6%) masses with solid components present in 81.8% of cases. However, the solid component showed isoenhancement in 63%. No matrix mineralization was present in 69.7% of cases. Quantitatively, the enhancement of soft tissue in CGCG was significantly higher than in ameloblastoma on histogram analysis (P < 0.05), with a minimum enhancement of > 49.05 HU in the tumour providing 100% sensitivity and 85% specificity in identifying a CGCG.

CONCLUSION

A multilocular, lytic sclerotic lesion with significant hyperenhancement in soft tissue, which spares the angle of the mandible and has matrix mineralization, should indicate prospective diagnosis of CGCG.

Prediction of ameloblastoma recurrence using random forest-a machine learning algorithm

The purpose of this study was to investigate whether ameloblastoma with a high likelihood of recurrence can be predicted using random forest model, a machine learning algorithm. Data were collected from patients treated for ameloblastoma between 1999 and 2019 at the University of Hong Kong. Fourteen clinical parameters were used to grow the decision trees to classify patients with or without ameloblastoma recurrence in the follow-up period. The random forest algorithm was computed 100 times in the training cohort (n = 100) and verified in the testing cohort (n = 50). The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used as the performance measurement of separability. One hundred and fifty patients (76 female, 74 male) were recruited, with a mean follow-up time of 103 months. Recurrence occurred in a total of 25 cases (16.7%) over the 20-year period. The AUC were calculated for the median and mean ROC curves; these were 0.777 and 0.825, respectively. The results showed that random forest model was able to predict recurrence of ameloblastoma with reliable accuracy. The four most important variables influencing ameloblastoma recurrence were the time elapsed from treatment, initial surgical treatment, tumour size, and radiographic presentation. This study provides insights into the detection of high-risk patient groups to monitor recurrence. Further application of random forest to other diseases could greatly benefit clinical decisions.

Accuracy of fine needle aspiration cytology in the preoperative diagnosis of malignant non-odontogenic tumors of the orofacial region

BACKGROUND

This study aims to determine the association between preoperative cytopathological diagnosis and the histopathological diagnosis of orofacial non-odontogenic tumors. It is also, to determine the sensitivity, specificity and accuracy of fine needle aspiration cytology (FNAC) in the preoperative diagnosis of orofacial malignant non-odontogenic tumors in a Nigerian population.

METHODS

A 9-month prospective study in which preoperative FNAC followed by open biopsy for confirmatory histopathological evaluation was performed for consenting patients with orofacial swellings. Patients histopathologically diagnosed as non-odontogenic tumors were selected for the study.

RESULTS

There were 40 (83.3%) histopathologically diagnosed non-odontogenic tumors. The female to male ratio was 1.7:1 and the patients' mean age was 36 + 21.9 years. The mandible (n = 4, 10.0%) and the preauricular area (n = 4, 10.0%) were the most common sites affected. The cytopathological diagnosis showed 28 (70.0%) of the lesions were malignant, 7 (17.5%) were benign neoplasms and 5 (12.5%) were reactive/inflammatory swellings. The histopathological diagnosis was predominantly malignant (n = 29, 72.5%), consisting mostly of non-Hodgkin's lymphoma (n = 12, 30.0%). There was significant association (P = .000) between cytopathological diagnosis and histopathological diagnosis of the malignant orofacial non-odontogenic tumors. The sensitivity of FNAC to detect malignant orofacial nonodontogenic tumors was 93.1%, the specificity was 90.9%, the positive predictive value was 96.4%, the negative predictive values was 83.3% and the accuracy was 92.5%.

CONCLUSION

The accuracy of FNAC in the diagnosis of orofacial malignant non-odontogenic orofacial tumors is high and hence recommended as a routine preoperative diagnostic tool.

Upregulation of eukaryotic translation initiation factor 3 subunit a promotes cell survival in ameloblastoma

OBJECTIVES

This study aimed to detect the expression of eukaryotic translation initiation factor 3 subunit a (eIF3a) in ameloblastoma (AB) tissues compared with normal oral mucosa (NOM) tissues and investigate the roles of eIF3a in the immortalized ameloblastoma cell line (AM-1) cell proliferation and apoptosis.

STUDY DESIGN

We performed immunohistochemistry to determine the expression of eIF3a in AB tissues (n = 83) and NOM tissues (n = 20). Real time-quantitative polymerase chain reaction and Western blot analyses were conducted with AB tissues (n = 30) and NOM tissues (n = 6). The correlation between eIF3a expression and the clinical/pathologic features of patients with AB is also presented. The functional role of eIF3a in AM-1 cells was assessed with lentiviral vector-mediated shRNA (small hairpin RNA).

RESULTS

Our results indicated that eIF3a was significantly upregulated in AB. Additionally, eIF3a knockdown in AM-1 cells significantly inhibited cell proliferation and promoted apoptosis.

CONCLUSIONS

These data indicate that eIF3a facilitates the survival of AB cells and may serve as a promising therapeutic target in AB.

Maxillary ameloblastoma: results of the treatment in 11 patients

Introduction: Surgery of maxilla ameloblastoma is mutilating and the tumor propensity for recurrence high. Patients and Methods: The oral and visual functions, facial morphology and tumor recurrence in 11 patients after maxillary ameloblastoma surgery are retrospectively reviewed. Results: Facial morphology was satisfactory in 7 patients who had all tumor removal by a type 1 or 2A maxillectomy and surgical wound closure. Out of these patients, 4 who had dental rehabilitation by conventional prosthesis presented satisfactory mastication. Four patients subjected to the tumor removal by a type 3 maxillectomy had all facial asymmetry. Out of these, 1 patient who did not have the orbital floor defect repair presented diplopia and enophtalmos, 2 patients subjected to the palate defect repair by a prosthetic obturator or oral mucosa had elocution impairment. The tumor recurrence occurred in 2 patients after tumor enucleation and in 1 patient after radical surgery out of 8 patients who had a postoperative follow-up. Discussion: In ameloblastoma surgery, achieving both the tumor recurrence prevention and a satisfactory facial reconstruction is challenging. Conclusion: Avoiding the tumor recurrence should be the major goal when patient post-surgical follow-up cannot be guaranteed.

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/β-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.