Intraoral confocal microscopy of suspicious oral lesions: a prospective case series

Abstract

Background Oral squamous cell carcinoma (OSCC) accounts for more than 90% of oral epithelial malignancies and often arises from precursor lesions, whose diagnosis is based on biopsy and histopathology. In vivo reflectance confocal microscopy (RCM) images the vital tissues at microscopic resolution, well correlating with conventional histopathology, but it is poorly investigated in oral oncology. The present work aims to describe RCM cytoarchitectural findings in oral mucosae affected by OSCC and its precursors. Materials and Methods A series of clinically suspected oral lesions underwent RCM imaging before conventional biopsy and histopathological assessment in order to identify features suggestive of tumoral changes. Sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV) of RCM compared to histopathology were calculated. Results Totally, 30 sites in 20 patients were considered and clinically classified into 16 “leukoplakia”/“ traumatism”, nine erosive‐ulcerative lesions, three verrucous lesions, and two healthy mucosae, as control. The histopathological “positivity,” due to the presence of various degrees of dysplasia and/or neoplasia, was found in 11 lesions; the RCM “positivity” was referred to nine lesions reporting the RCM detection of polymorphism, multinucleated cells, irregular cellular maturation, altered nuclear/cytoplasm ratio, and abnormal blood vessels. After excluding three verrucous lesions from the RCM analysis, due to the low laser penetration through the hyperkeratotic layers, the results well correlated with histopathology, reporting 1.000 (SE), 0.933 (SP), 0.909 (PPV), and 1.000 (NPV). Conclusion RCM can reveal dysplastic/neoplastic signs occurring in oral lesions, thus supporting their diagnostic pathway.

Features of oral squamous cell carcinoma in ex vivo fluorescence confocal microscopy

“…Cellular pleomorphism, increased nuclear-cytoplasmic ratios, multi-nucleolated keratinocytes, rod nucleoli at suprabasal layers, and large dilated blood vessels were present in moderate and poorly differentiated OSCCs. 21 In our study, cellular pleomorphism and anisocytosis could be Our results demonstrate that the classic histological patterns can also be applied in ex vivo pictures and be supportive in a rapid diagnosis of OSCC. This technology might be supportive in differentiation of poorly and well/moderately differentiated entities, given the correct positioning of a sample in the scanner of ex vivo FCM.…”

“…in 2019 enriched the in vivo confocal descriptions by identifying cytological and architectural disarray, mainly expressed by the finding of keratin pearls in well‐differentiated OSCCs. Cellular pleomorphism, increased nuclear‐cytoplasmic ratios, multi‐nucleolated keratinocytes, rod nucleoli at suprabasal layers, and large dilated blood vessels were present in moderate and poorly differentiated OSCCs 21 …”

Reflectance confocal microscopy characteristics of oral lichen planus: An analysis of 47 cases in a Chinese cohort

“…Cellular disarrangement, pleomorphism, dispersed nuclei and large intercellular spaces were also identified. In 2019, Contaldo et al (15) reported that the most characteristic RCM criteria for malignancies were cytological and architectural disarray in well-differentiated oral squamous cell carcinoma, as well as cellular pleomorphism, increased nuclear-cytoplasmic ratios and multi-nucleolated keratinocytes in moderately/poorly differentiated oral squamous cell carcinoma. These findings were similar to those in the present study, which indicated that these features may suggest underlying cancerous changes in OLP lesions.…”

“…The features of RCM are difficult to identify in the deeper layer of the sections due to fact the upper tissue layer interferes with image formation (28). It has also been reported that in strongly keratinized lesions, images cannot be clearly identified (15). Subclinical inflammation and alteration may be present on the clinically unaffected areas which would also interfere with specificity values.…”

“…The contrast of RCM images relies on the different refractive index of subcellular components (13). A number of studies assessing the application of RCM in OLP have been previously reported and RCM cellular and Reflectance confocal microscopy characteristics of oral lichen planus: An analysis of 47 cases in a Chinese cohort architectural findings have been described (14)(15)(16)(17). However, to the best of our knowledge, relevant studies in a Chinese cohort have not been performed.…”