Single-cell transcriptomic analysis of gingivo-buccal oral cancer reveals two dominant cellular programs.

Oral squamous cell carcinoma of the gingivo-buccal region (OSCC-GB) is the most common cancer among men in India, and is associated with poor prognosis and frequent recurrence. Cellular heterogeneity in OSCC-GB was investigated by single-cell RNA sequencing of tumors derived from the oral cavity of 12 OSCC-GB patients, 3 of whom had concomitant presence of a precancerous lesion (oral submucous fibrosis [OSMF]). Unique malignant cell types, features, and phenotypic shifts in the stromal cell population were identified in oral tumors with associated submucous fibrosis. Expression levels of FOS, ATP1A, and DUSP1 provided robust discrimination between tumors with or without the concomitant presence of OSMF. Malignant cell populations shared between tumors with and without OSMF were enriched with the expression of partial epithelial-mesenchymal transition (pEMT) or fetal cell type signatures indicative of two dominant cellular programs in OSCC-GB-pEMT and fetal cellular reprogramming. Malignant cells exhibiting fetal cellular and pEMT programs were enriched with the expression of immune-related pathway genes known to be involved in antitumor immune response. In the tumor microenvironment, higher infiltration of immune cells than the stromal cells was observed. The T cell population was large in tumors and diverse subtypes of T cells with varying levels of infiltration were found. We also detected double-negative PLCG2+ T cells and cells with intermediate M1-M2 macrophage polarization. Our findings shed light on unique aspects of cellular heterogeneity and cell states in OSCC-GB.

Application of Diode Laser in Excision of a Peripheral Ameloblastoma - A Case Report.

Rationale: Occurrence of peripheral ameloblastoma (PA) is rare. Excision of PA by diode laser is infrequent. Patient Concerns: A 27-year-old female patient presented with an asymptomatic mass on the retromolar trigone for the past one year. Diagnosis: Incisional biopsy showed aggressive PA. Treatment: The lesion was excised using a diode laser under local anaesthesia. The excised specimen revealed histopathological features of the acanthomatous variant of PA. Outcomes: The patient was followed up for two years without any evidence of recurrence. Take-Away Lessons: Diode laser is an acceptable alternative to conventional scalpel excision for intraoral soft tissue lesions, whereas, in the case of PA, it proves to be no exception.