Twin-pair rete ridge analysis: a computer-aided method for facilitating objective histopathological distinction between epi- thelial dysplasia and carcinoma in-situ of the oral mucosa

Epithelial dysplasia and carcinoma in-situ (CIS) of the oral mucosa are two different borderline grades similar to each other, and it is difficult for pathologists to distinguish these two lesions on hematoxylin and eosin-stained sections only. To support objective differential diagnoses, we have developed a new computer-aided analysis system. The method was based on a comparison of the elevation levels in the drop shape between twin-pairs of neighboring rete ridges. The dissimilarity of the drop shape was defined by the roundness difference between a pair of rete ridge units. All the steps were performed using a graphical user interface. The similarity levels in epithelial dysplasia were higher than those in CIS, whose histopathological diagnoses were conventionally made by experienced pathologists. The developed image processing method showed good promise for the computer-aided pathological assessment of oral borderline malignancies in clinical practice. [Oral Med Pathol 2010; 14: 89-97 doi: 10.3353/omp.14.89]