Dysplasia Should Not Be Ignored in Lichenoid Mucositis

Abstract

Oral lichen planus is categorized as a potentially malignant condition by the World Health Organization; however, some argue that only lichen planus with dysplasia have malignant potential. Many pathologists call lichen planus with dysplasia "dysplasia with lichenoid mucositis (LM)" or "LM with dysplasia." Previous research has shown that certain high-risk patterns of loss of heterozygosity (LOH) in dysplastic lesions are associated with significantly increased cancer risk. However, LM without dysplasia lacks such molecular patterns, supporting the hypothesis that LM, by itself, is not potentially malignant and that only those with dysplasia have malignant potential. To further investigate the premalignant nature of LM with dysplasia, this study compared the rate of malignant progression of dysplasia with LM with that of dysplasia without LM. Patients from a population-based prospective cohort study with >10 y of follow-up were analyzed. Study eligibility included a histological diagnosis of a primary low-grade dysplasia with or without LM. A total of 446 lesions in 446 patients met the selection criteria; 373 (84%) were classified as dysplasia without LM, while 73 (16%) were classified as dysplasia with LM. Demographic and habit information, clinical information, and outcome (progression) were compared between the 2 groups. Forty-nine of 373 cases of dysplasia (13%) progressed compared to 8% (6/73) of dysplasia with LM. However, the difference was not statistically different ( P = 0.24). The 3- and 5-y rate of progression did not differ between the groups (6.7% and 12.5% for dysplasia without LM and 2.9% and 6.6% for those with LM; P = 0.36). Progression was associated with nonsmoking, location at a high-risk site, and diagnosis of moderate dysplasia regardless of whether LM was present or not. Dysplasia with or without LM had similar cancer risk, and dysplasia should not be discounted in the presence of LM.

Dentinogenic ghost cell tumor: A bibliometric review of literature

“…This finding is supported by Rock et al, [13] who compared both the frequency and the time to malignant transformation in LD compared to that of dysplasia without lichenoid features. These results showed that a diagnosis of dysplasia, regardless of whether lichenoid changes were present, was significantly associated with progression.…”

“…However, interestingly, there was no significant difference in the proportion of malignant progression of LD compared to that of dysplasia, and time to progression did not differ between the groups. [13] Kim et al [14] used chromosomal in situ hybridization to assess the degree of genetic instability in OLP and LD. They found that there was an increase in the number of cells exhibiting a loss of genetic material in chromosome 9 in LD that progressed to OSCC.…”

Incidence of squamous cell carcinoma in oral lichen planus: a 25-year population-based study

“…Independent of oral lichen planus, patients may have oral epithelial dysplasia in the absence of lichenoid inflammation. Notably, these patients carry similar risks of malignant transformation . Although we did not study this population, clinicians should pay special attention to dysplasia irrespective of lichenoid mucositis.…”

Potentially malignant disorders of the oral cavity and oral dysplasia: A systematic review and meta‐analysis of malignant transformation rate by subtype

“…After title/abstract screening, 4324 papers were selected for abstract evaluation. Of these, 92 studies were included in the final analysis . Fourty‐six reports were on LP, 5 on OLL, 28 on LE, 8 on OE, 4 on OSF, and 11 on PVL (all the studies taken for every subgroup sum up to a figure higher than 92 because some studies focused on more than one OPMD).…”