Q&A: What is oral lichenoid dysplasia? A brief overview
Author: Sanketh DS, MDS
There are certain red and white oral mucosal lesions that may look like oral lichen planus(OLP) under the microscope! But on a closer look they may lack basal cell degeneration that OLP shows. In fact the basal cells may be very much intact and these lesions may possess bulbous rete ridges. On a more closer look they may reveal epithelial dysplasia too!
In 1978, Krutchkoff and associates, re-examined 223 cases of OLP that were reported to have become malignant. However, they reported that only 15 cases were truly OLP and the rest of the lesions only mimicked OLP. They called these lesions lichenoid dysplasia (LD). So why did they come to this conclusion? Though these lesions looked like OLP, on close examination, they found that the lesions,
a) lacked basal cell degeneration and in fact had broad and bulbous rete ridges.
b) showed a mixed inflammatory infiltrate having lymphocytes and plasma cells.
c) showed dysplastic features like nuclear pleomorphism & hyperchromasia, disordered stratification, mitotic figures and broad, bulbous rete ridges.
Since, the lesions had a lichen planus like inflammatory infiltrate or a “Lichenoid” infiltrate and showed epithelial dysplasia, they called them “Lichenoid dysplasia”. According to them, OLP does not show dysplasia. Hence they concluded that any lesion clinically diagnosed as OLP, may actually represent LD if it shows dysplasia under the microscope!
So is this lesion a distinct entity? Well… not exactly. There have been numerous research studies done after their controversial report, and they have only fueled confusion! Most pathologists agree that “Lichenoid dysplasia” is a confusing term. These lesions may actually represent cases of leukoplakia or erythroplakia, merely in addition to dysplasia, showing a lichenoid infiltrate. Thus the need for another term such as “lichenoid dysplasia” may not be warranted.
That being said, the argument that OLP does not show dysplasia has not reached a common consensus. There are reports which claim OLP can manifest dysplasia histologically.
However pathologists are cautious while making a diagnosis of oral lichen planus, since it has been shown with sufficient evidence that red and white lesions like leukoplakia or erythroplakia may mimic oral lichen planus both clinically and histologically.
It is agreed that using the term “lichenoid dysplasia” to represent such lesions may cause much confusion and they are better acknowledged as epithelial dysplastic lesions showing lichenoid features!
Lodi G, Scully C, Carrozzo M, Griffiths M, Sugarman PB, Thongprasom K. Current controversies in oral lichen planus: report of an international consensus meeting. Part 2. Clinical management and malignant transformation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100: 164–78.
Sanketh DS, Patil S, Swetha B. Oral lichen planus and epithelial dysplasia with lichenoid features: a review and discussion with special reference to diagnosis. J Investig Clin Dent. 2017 Aug;8(3). doi: 10.1111/jicd.12233. Epub 2016 Jul 21.
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