Three-Dimensional Reconstruction of Oral Tongue Squamous Cell Carcinoma at Invasion Front

Tomoo Kudo,Yuuichi Soeno,Kaori Sato,Takaaki Aoba,Yuji Taya,Hisao Yagishita,Yoshihito Shimazu,Toshiyuki Izumo

doi:10.1155/2013/482765

Abstract

We conducted three-dimensional (3D) reconstruction of oral tongue squamous cell carcinoma (OTSCC) using serial histological sections to visualize the architecture of invasive tumors. Fourteen OTSCC cases were collected from archival paraffin-embedded specimens. Based on a pathodiagnostic survey of whole cancer lesions, a core tissue specimen (3 mm in diameter) was dissected out from the deep invasion front using a paraffin tissue microarray. Serial sections (4 μm thick) were double immunostained with pan-cytokeratin and Ki67 antibodies and digitized images were acquired using virtual microscopy. For 3D reconstruction, image registration and RGB color segmentation were automated using ImageJ software to avoid operator-dependent subjective errors. Based on the 3D tumor architecture, we classified the mode of invasion into four types: pushing and bulky architecture; trabecular architecture; diffuse spreading; and special forms. Direct visualization and quantitative assessment of the parenchymal-stromal border provide a new dimension in our understanding of OTSCC architecture. These 3D morphometric analyses also ascertained that cell invasion (individually and collectively) occurs at the deep invasive front of the OTSCC. These results demonstrate the advantages of histology-based 3D reconstruction for evaluating tumor architecture and its potential for a wide range of applications.

Highlights

Oral tongue squamous cell carcinoma (OTSCC) is the most prevalent head and neck cancer, and the presence of occult neck metastases is the main predictor of outcome in patients with early-stage OTSCC [1,2,3,4]
These OTSCC cases, labeled A–N, are listed in order of the measured depth of infiltration. By initially dividing these cases into three classes, we found that four out of the five OTSCC cases with “pushing and bulky architecture” belonged to the shallow class, while three out of four cases with “trabecular architecture” were in the intermediate class
The present 3D image reconstruction proved the feasibility of volumetric isolation of OTSCC architecture segmented from the surrounding stroma at high spatial resolution

Summary

Introduction

Oral tongue squamous cell carcinoma (OTSCC) is the most prevalent head and neck cancer, and the presence of occult neck metastases is the main predictor of outcome in patients with early-stage OTSCC [1,2,3,4]. It has been documented that the depth of infiltration of the primary tumor correlates significantly with the rate of regional nodal metastases [5,6,7], but the specific cut-off value for the depth of infiltration distinguishing high-risk and low-risk patients remains controversial [8, 9]. It is well known that the histological features of OTSCC differ widely between different regions within the same tumor, and much effort has been given to explore specific invasion patterns that may have prognostic value. The deep invasion patterns of OTSCC are usually classified into three

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Discussion

Conclusion