Oral Manifestations of Coronavirus Disease 2019 (COVID-19): A Comprehensive Clinicopathologic and Immunohistochemical Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents rapid transmission and significant mortality worldwide. It is responsible for coronavirus disease 2019 (COVID-19). The disease presents diverse clinical symptoms, including fever, cough, dyspnea, and pneumonia. However, other manifestations associated with COVID-19 need to be clarified, leading specialists to an early diagnosis and better prognosis. We describe the spectrum of clinicopathologic COVID-19-related oral lesions that can be the first and/or the unique manifestation of the disease. Fourteen patients with a mean age of 58 years (range: 23 to 88 y) with oral lesions were included. All patients were confirmed to be infected with SARS-CoV-2 by reverse transcription polymerase chain reaction testing. Patients demonstrated mild symptoms, including dysgeusia, anosmia, fever, and headache. The lesions were recognized and classified into 2 groups: (1) lesions caused by ischemia and/or hemorrhage and (2) lesions secondary to inflammatory events associated with viral load. The palate was most affected (n=8), followed by the tongue (n=4), and both the lip and palate (n=2). Histologic analysis demonstrated thrombosis of small arteries and capillaries, associated with areas of hemorrhage and chronic inflammatory infiltrate. Immunohistochemistry showed positive staining for spike protein (SARS-CoV and SARS-CoV-2) and angiotensin-converting enzyme 2 in the surface epithelium, salivary glands, inflammatory cells, and endothelial cells. Although the incidence of oral lesions among patients infected with SARS-CoV-2 appears to be uncommon, these findings suggest that the oral mucosa can also be a target organ for SARS-CoV-2.

Bilateral multiple oncocytic cysts of the parotid gland in type 2 diabetes patients.

AIMS: The hallmarks of type 2 diabetes (T2D) are hyperglycaemia and insulin resistance. These factors, at the cellular level, are associated with mitochondrial dysfunction and increased glucose uptake. Such events are poorly explored in the context of the salivary glands. In this study, we present a series of eight cases of a distinct salivary gland lesion characterised by multiple oncocytic cysts, and we provide new pathological insights regarding its pathogenesis. METHODS AND RESULTS: Seven patients (87.5%) had confirmed T2D, and obesity was identified in five (62.5%) patients. Clinically, the patients showed bilateral parotid gland swelling with recurrent episodes of pain and enlargement. Imaging examination revealed multiple cystic lesions in both parotid glands. Microscopically, the parotid glands showed multiple cysts of different sizes, lined by oncocytic epithelial cells. Intraluminally, strongly eosinophilic glass-like crystalloid material was observed. Immunohistochemical studies were performed, and the most notable finding was glucose transporter 1 (GLUT1) overexpression in the oncocytic cysts which is not observed in any other oncocytic lesion of patients without T2D. In addition, high expressions of mitochondrial antigen, fission 1 protein and mitofusin-2 were observed in the oncocytic epithelium of the cysts. Furthermore, most of the oncocytic cysts showed a pattern of cytokeratin expression consistent with striated ducts. CONCLUSIONS: These results strongly suggest that T2D is associated with alterations in GLUT1 expression in the cells of striated ducts with mitochondrial dysfunction, causing a hyperplastic process characterised by multiple oncocytic cysts. For this lesion, the designation of 'diabetes-associated-bilateral multiple oncocytic cysts of the parotid gland' is proposed.

FGF-2 and FGFR-1 might be independent prognostic factors in oral tongue squamous cell carcinoma.

AIMS: Fibroblast growth factor (FGF)-2 and fibroblast growth factor receptor (FGFR)-1 are associated with tumour invasiveness, cell proliferation, angiogenesis, and metastasis. The aims of this study were to investigate FGF-2 expression and FGFR-1 expression in oral epithelial dysplasia (OED) and oral tongue squamous cell carcinoma (OTSCC), and their correlation with OTSCC patients' prognosis. METHODS AND RESULTS: One hundred and sixty-seven cases were retrospectively selected, including 85 surgical specimens of patients with OTSCC, 46 incisional biopsies of OTSCC, and 36 incisional biopsies of OED. Tissue sections were subjected to immunohistochemical staining for FGF-2 and FGFR-1, and digitally scored. Elevated scores of FGF-2 and FGFR-1 immunostaining were associated with high-grade OEDs. FGF-2 positivity in the stroma was associated with vascular invasion and a worse prognosis, in both overall survival (OS) and disease-free survival (DFS) analyses, in univariate and multivariate models. FGFR-1 positivity in the stroma was correlated with lymph node metastasis and distant metastasis. FGFR-1 expression in either the malignant cells or the stroma was strongly correlated with shorter OS and DFS. CONCLUSIONS: Taken together, our findings suggest that increased FGF-2 expression and increased FGFR-1 expression are associated with high-grade OEDs, and are correlated with the presence of metastasis and adverse outcomes in OTSCC patients.

Expression of FGF-2/FGFR-1 in normal mucosa, salivary gland, preneoplastic, and neoplastic lesions of the oral cavity.

Fibroblast growth factor 2 (FGF-2) is a multifunctional cytokine expressed in several tissues and involved in a wide variety of biologic activities, with one low molecular weight (LMW) protein present in the cytosol, which is secreted, acting via its receptors (FGFRs), and four high molecular weight (HMW) proteins located in the nucleus. Fibroblast growth factor receptor (FGFR) family has four (FGFR1-4) transmembrane tyrosine kinase receptors expressed on several cell types, and FGFR-1 has been indicated as a potential molecular target in several types of cancer, including oral squamous cell carcinoma (OSCC). The FGF-2/FGFR-1 expression has been studied in the oral cavity, and it was associated with the wound repair process, the development of benign and malignant salivary gland tumors, besides being related to oral potentially malignant disorders (OPMDs) and OSCC. Hence, we critically review the currently available data on FGF-2/FGFR-1 expression in the normal mucosa and lesions of the oral cavity.

Sebaceous adenocarcinomas of the major salivary glands: a clinicopathological analysis of 10 cases.

AIMS: Sebaceous carcinomas are uncommon malignant cutaneous tumours originating from the pilosebaceous unit. Although its occurrence is mostly common in peri-ocular glands, other anatomical regions of the head and neck may be affected, including major and minor salivary glands. METHODS AND RESULTS: We describe a series of sebaceous adenocarcinomas of the parotid and submandibular glands. The mean age was 62.1 (range = 31-90) years. Two patients (20%) presented regional or distant metastasis to mandible and lungs. All cases were positive for cytokeratins (AE1AE3 and CK-5), epithelial membrane antigen and adipophilin and negative for androgen receptor, Factor XIIIa, S-100, vimentin and perforin. MLH1 and MSH2 were expressed in the nuclei of most tumour cells, and one case showed loss of MSH2 expression. Proliferative index (assessed by Ki-67 expression) and microvessel density (CD34-positive vessels) were higher in metastasis-associated cases. P63 expression was noted in the periphery of the tumour nests, in the basaloid cells, with a mean of 69.2% nuclear positivity. CONCLUSIONS: The sebaceous adenocarcinoma of salivary glands is rare and may show an unfavourable outcome; therefore, its correct diagnosis may be challenging. For this reason, immunohistochemical studies, including adipophilin in particular, constitute an important diagnostic tool.