Site-Coded Oral Squamous Cell Carcinoma Evaluation by Optical Coherence Tomography (OCT): A Descriptive Pilot Study

Abstract

Optical Coherence Tomography (OCT) is an emerging non-invasive method for oral diagnostics, proving to be a practicable device for epithelial and subepithelial evaluation. The potential validity of OCT in oral cancer assessment has been explored but, to date, there are very few investigations conducted with a systematic comparison between clinical/histological and OCT parameters, especially in strict reference to the anatomical site-codification of the oral mucosa. In this regard, our study performed a two-steps evaluation (in vivo OCT and histological investigations) of suspected OSCCs, progressively recruited, using as references the OCT images of the same site-coded healthy mucosa, to provide as much as possible site-specific determinants. Thirty histologically confirmed OSCCs were recruited. Specific OCT mucosal features (SEL-Stratified Epithelial Layer; BM-Basement Membrane; LP-Lamina Propria) were registered and processed using the SRQR (Standards for Reporting Qualitative Research) statement. The systematic dual descriptive OCT analysis revealed that OSCC scans present a complete alteration of epithelial (KL, SEL) and subepithelial (BM, LP) layers with a site-specificity characteristic; moreover, peculiar OCT configurations such as "icicle-like" structures could be strongly suggestive of neoplastic infiltration. This study supports the OCT use for the development of more specific optical structural models applied to oral carcinogenesis.

Keywords: diagnostic pattern; early diagnosis; optical biopsy; optical coherence tomography; oral cancer.

Figure 1

Clinical, OCT and histopathology images of a case of OSCC on the dorsal surface of the tongue compared with the same healthy site (code C02.0). (a,b): Clinical and OCT images of healthy mucosa of dorsal surface of tongue; the site of in vivo OCT evaluation is indicated with a white circle. (c–e): Clinical, OCT and histopathological images (H-E stain; original magnification ×25) of OSCC on dorsal surface of tongue; the sites of in vivo OCT evaluation are indicated with a black circle; “icicle-like” structures are indicated with white arrows; superficial ulcerations are indicated by yellow arrows. An asterisk (*) indicates the thin transparent plastic wrapping around the scanning probe F—Lingual papillae; #—Subpapillary spaces; SEL—Stratified Epithelial Layer; BM—Basement Membrane; LP—Lamina Propria.

Figure 2

Clinical, OCT and histopathology images of two cases of OSCC on the lateral borders of the tongue compared with the same healthy site (code C02.1). (a,b): Clinical and OCT images of healthy mucosa of the border of tongue; the site of in vivo OCT evaluation is indicated with a white circle. (c–h): Clinical, OCT and histopathological images (H-E stain; original magnification ×25) of two OSCCs on the border of tongue; the site of in vivo OCT evaluation is indicated with a black circle; “icicle-like” structures are indicated with white arrows; superficial ulcerations and exophytic morphology are indicated by yellow arrows and yellow box, respectively; streaking pattern of LP is indicated by a dotted orange box. KL–Keratinized layer; SEL—Stratified Epithelial Layer; BM—Basement Membrane; LP—Lamina Propria.

Figure 3

Clinical, OCT and histopathology images of a case of OSCC on the ventral surface of the tongue compared with the same healthy site (code C02.2). (a,b): Clinical and OCT images of healthy mucosa of the ventral surface of the tongue; the site of in vivo OCT evaluation is indicated with a white circle. (c–e): Clinical, OCT and histopathological images of (H-E stain; original magnification ×25) confirmed OSCC on the ventral surface of tongue; the site of in vivo OCT evaluation is indicated with a black circle. An asterisk (*) indicates the thin transparent plastic wrapping around the scanning probe; superficial ulcerations are indicated by a yellow arrow. SEL—Stratified Epithelial Layer; BM—Basement Membrane; LP—Lamina Propria; V–vascular structures of sublingual area.

Figure 4

Clinical, OCT and histopathology images of three cases of OSCCs on low anterior alveolar mucosa and mandibular gingiva compared with the same healthy site (code C03.1). (a,b): Clinical and OCT images of healthy mucosa of lower alveolar mucosa and gingiva; the site of in vivo OCT evaluation is indicated with a white circle. (c–i,l,m): Clinical, OCT and histopathological images (H-E stain; original magnification ×25) of three OSCCs on lower anterior and left alveolar mucosa; the site of in vivo OCT evaluation is indicated with a black circle; “icicle-like” structures are indicated with white arrows. Microbial proliferation on epithelial flaking is indicated by red ovals; the exophytic growth zones of the verrucous variant of OSCC are indicated by red boxes; a dashed line in (g) separates the right (healthy) from the left (OSCC) portions of the image. KL–Keratinized layer; SEL—Stratified Epithelial Layer; BM—Basement Membrane; LP—Lamina Propria.

Figure 5

Clinical, OCT and histopathology images of OSCCs sited on buccal mucosa compared with the same healthy site (code C06.0). (a,b): Clinical and OCT images of healthy buccal mucosa; the site of in vivo OCT evaluation is indicated with a white circle (c–i,l–s): Clinical, OCT and histopathological images (H-E stain; original magnification ×25 in (e,h,p,s); original magnification ×100 in (m)) of five OSCCs on buccal mucosa; the site of in vivo OCT evaluation is indicated with a black circle; “icicle-like” structures are indicated with white arrows; fibrin deposits are indicated with a yellow rhombus. KL–Keratinized layer; SEL—Stratified Epithelial Layer; BM—Basement Membrane; LP—Lamina Propria.