Can SARS-CoV-2 screening in oral biopsies aid epidemiological surveillance?

BACKGROUND: Three years after the first confirmed COVID-19 case in Brazil, the outcomes of Federal government omissions in managing the crisis and anti-science stance heading into the pandemic have become even more evident. With over 36 million confirmed cases and nearly 700 000 deaths up to January 2023, the country is one of the hardest-hit places in the world. The lack of mass-testing programs was a critical broken pillar responsible for the quick and uncontrolled SARS-CoV-2 spread throughout the Brazilian population. Faced with this situation, we aimed to perform the routine SARS-CoV-2 screening through RT-qPCR of oral biopsies samples to aid in the asymptomatic epidemiological surveillance during the principal outbreak periods. METHODS: We analyzed 649 formalin-fixed paraffin-embedded oral tissue samples from five important oral and maxillofacial pathology laboratories from the north, northeast, and southeast geographic regions of Brazil. We also sequenced the whole viral genome of positive cases to investigate SARS-CoV-2 variants. RESULTS: The virus was detected in 9/649 analyzed samples, of which three harbored the Variant of Concern Alpha (B.1.1.7). CONCLUSION: Although our approach did not value aiding asymptomatic epidemiological surveillance, we could successfully identify a using FFPE tissue samples. Therefore, we suggest using FFPE tissue samples from patients who have confirmed diagnosis of SARS-CoV-2 infection for phylogenetic reconstruction and contraindicate the routine laboratory screening of these samples as a tool for asymptomatic epidemiological surveillance.

Oral localized amyloidosis.

This report describes two cases of oral localized amyloidosis (LA). In case 1, a 52-year-old man appeared with painful slightly, yellowish multiple nodules located on the dorsum of the tongue, of unknown duration. Incisional biopsy was performed, and the histopathologic analysis revealed a homogeneous, eosinophilic, and extracellular material. Congo red stain showed salmon pink coloration at light microscopy and apple-green birefringence at polarized light. In case 2, a 74-year-old man presented asymptomatic nodular lesions on the labial commissures with duration of several months. An excisional biopsy was performed in both lesions, and microscopically the specimen demonstrated the same histopathologic features of the case 1. Furthermore, amyloidosis with systemic involvement was excluded after investigations for both patients. Thus, the final diagnosis for both cases was LA. The patient 1 refused the surgical excision of the residual lesion, and in both cases, no signs of clinical and systemic progression were observed after 24 and 84 months of follow up. Although it is rare, LA should be considered in the differential diagnosis of multiple or single yellowish nodules on the oral cavity.

Oral Adult Rhabdomyoma.

This report describes a case of an adult rhabdomyoma (ARM) occurring in the oral cavity. A 47-year-old man was referred for the diagnosis of a painless, well-circumscribed, submucous nodule located on the floor of the mouth, measuring approximately 6.0 cm in length. Computed tomography revealed a well-defined, solid, and hypodense mass. A benign salivary gland or mesenchymal tumor were the main diagnostic hypotheses. Under local anesthesia, the patient underwent surgical excision. Microscopically, the tumor comprised large polygonal well-defined cells with abundant, eosinophilic granular cytoplasm with cross striations. No atypia or mitosis was observed. The cells were positive for muscle-specific actin, desmin, and sarcomeric alpha-actin. Based on these features, a diagnosis of ARM was established. No recurrence was observed after 48 months. Although rare, ARM should be considered in the differential diagnosis of oral submucosal nodules, especially those located on the floor of the mouth.