The Role of Immunohistochemistry for Primary Oral Diagnosis in a Brazilian Oral Pathology Service

Feasibility study of ResNet-50 in the distinction of intraoral neural tumors using histopathological images

BACKGROUND

Neural tumors are difficult to distinguish based solely on cellularity and often require immunohistochemical staining to aid in identifying the cell lineage. This article investigates the potential of a Convolutional Neural Network for the histopathological classification of the three most prevalent benign neural tumor types: neurofibroma, perineurioma, and schwannoma.

METHODS

A model was developed, trained, and evaluated for classification using the ResNet-50 architecture, with a database of 30 whole-slide images stained in hematoxylin and eosin (106, 782 patches were generated from and divided among the training, validation, and testing subsets, with strategies to avoid data leakage).

RESULTS

The model achieved an accuracy of 70% (64% normalized), and showed satisfactory results for differentiating two of the three classes, reaching approximately 97% and 77% as true positives for neurofibroma and schwannoma classes, respectively, and only 7% for perineurioma class. The AUROC curves for neurofibroma and schwannoma classes was 0.83%, and 0.74% for perineurioma. However, the specificity rate for the perineurioma class was greater (83%) than in the other two classes (neurofibroma with 61%, and schwannoma with 60%).

CONCLUSION

This investigation demonstrated significant potential for proficient performance with a limitation regarding the perineurioma class (the limited feature variability observed contributed to a lower performance).

Contribution of public oral pathology services to the diagnosis of oral and oropharyngeal cancer in Brazil

This study aimed to evaluate the contribution of oral and maxillofacial pathology laboratories (OMPLs) in Brazilian public universities to the diagnosis of lip, oral cavity, and oropharyngeal squamous cell carcinoma (SCC). A cross-sectional study was performed using biopsy records from a consortium of sixteen public OMPLs from all regions of Brazil (North, Northeast, Central-West, Southeast, and South). Clinical and demographic data of patients diagnosed with lip, oral cavity, and oropharyngeal SCC between 2010 and 2019 were collected from the patients' histopathological records. Of the 120,010 oral and maxillofacial biopsies (2010-2019), 6.9% (8,321 cases) were diagnosed as lip (0.8%, 951 cases), oral cavity (4.9%, 5,971 cases), and oropharyngeal (1.2%, 1,399 cases) SCCs. Most cases were from Brazil's Southeast (64.5%), where six of the OMPLs analyzed are located. The predominant profile of patients with lip and oral cavity SCC was Caucasian men, with a mean age over 60 years, low schooling level, and a previous history of heavy tobacco consumption. In the oropharyngeal group, the majority were non-Caucasian men, with a mean age under 60 years, had a low education level, and were former/current tobacco and alcohol users. According to data from the Brazilian National Cancer Institute, approximately 9.9% of the total lip, oral cavity, and oropharyngeal SCCs reported over the last decade in Brazil may have been diagnosed at the OMPLs included in the current study. Therefore, this data confirms the contribution of public OMPLs with respect to the important diagnostic support they provide to the oral healthcare services extended by the Brazilian Public Health System.

Impact of the COVID-19 pandemic on Public University Laboratories of oral and maxillofacial pathology - a Brazilian multicenter study

OBJECTIVE

To evaluate the impact of the COVID-19 pandemic on the number of diagnoses of oral and maxillofacial lesions in public laboratories after one year of COVID-19 outbreak in Brazil.

MATERIAL AND METHODS

This is a cross-sectional study. Biopsies submitted to histopathologic examination from March 2019 to February 2020 (pre-pandemic period) and from April 2020 to March 2021 (pandemic period) in nine Brazilian public oral pathology laboratories were retrieved and the number of diagnoses, types of lesion, and percentage changes during both periods were analyzed.

RESULTS

There were 7,389 diagnoses in the pre-pandemic period and 2,728 in the pandemic era, indicating a reduction of 63.08%. The reduction was 64.23% for benign lesions and 49.48% for malignant lesions, with a 50.64% reduction in squamous cell carcinoma. The largest decreases were observed in April 2020 and January 2021.

CONCLUSION

An important reduction in the diagnoses of benign and malignant lesions was noted in the Brazilian public oral pathology laboratories during the first year of the COVID-19 pandemic.