Prognostic outcomes of OSCC derived from proliferative verrucous leukoplakia: a systematic review

Oral Carcinoma Arising Under Implant-Supported Prosthesis: Progression of Proliferative Verrucous Leukoplakia Initially Mimicking Lichen Planus

Proliferative verrucous leukoplakia (PVL) is a non-homogenous type of oral leukoplakia, characterized by multifocal white plaques, propensity to recur after treatment, with strong tendency towards malignant transformation. Interestingly, some studies show that, at initial stages, PVL may resemble oral lichen planus (OLP), potentially leading to misdiagnosis. A 52-year-old woman, with a previous OLP diagnosis, was referred to our service for implant installation and follow-up of OLP lesions. After clinicopathological re-evaluation, a diagnosis of PVL (early stage) was made, and a maxillary full-arch implant-supported prosthesis supported by implants was installed. After 6 years of follow-up, the patient developed squamous cell carcinoma around the implants. The current case emphasizes that PVL patients with oral lesions suggesting peri-implantitis or peri-implant mucositis deserve a more meticulous investigation.

Oral cancers preceded by proliferative verrucous leukoplakia exhibit distinctive molecular features

OBJECTIVE

Proliferative verrucous leukoplakia (PVL) has high rates of malignant transformation into oral squamous cell carcinoma (OSCC), but the clinical and evolutionary pattern of OSCC from PVL (PVL-OSCC) is more favorable than that of OSCC not preceded by PVL (OSCC). Here, we aimed to explore the pathophysiologic differences between PVL-OSCC and OSCC through transcriptomic and DNA methylation analyses.

MATERIALS AND METHODS

In this case-control study, oral biopsies from 8 PVL-OSCC and 10 OSCC patients were obtained for global sequencing using RNAseq and a genome-wide DNA methylation analysis via the Infinium EPIC Platform (graphical abstract).

RESULTS

One hundred and thirty-three differentially expressed genes (DEGs) were detected, 94 of them upregulated in OSCC. Most of these genes were previously described in cancer and associated with prognosis. The integrative analysis revealed 26 DEGs, corresponding to 37 CpGs, whose promoters were regulated by DNA methylation. Twenty-nine of the CpGs were found as hypermethylated in PVL-OSCC. Only 5 of the genes that were aberrantly methylated and differentially expressed were upregulated in PVL-OSCC patients, whereas 21 were underexpressed.

CONCLUSIONS

PVL-OSCC patients presented lower expression of cancer-related genes. Hypermethylation of the promoter region of many genes was also noticed, indicating that DNA methylation could be a regulatory mechanism.

Proliferative Verrucous Leukoplakia Presenting as a Ring Around the Collar and Cancer: A Case Report

Proliferative verrucous leukoplakia (PVL) is an oral mucosa lesion with a high rate of malignant transformation. The diagnosis is often difficult, especially when the initial lesion is a simple homogeneous white leukoplakia, and when located only on the gingiva or palate. Moreover, the anatomopathological analysis is non-specific in the initial stages. The gingival PVL localisation (gPVL) is described as the most aggressive form with the highest rate of malignant transformation. Cases with a unique gingival localisation are rare, described with a "ring around the collar" clinical form. Considering the difficulty of early diagnosis of gPVL, we report the case of a 72-year-old woman, who presented "white lesions on her gingiva" with a slight discomfort in February 2019. The lesion was initially limited to the buccal part of the mandibular right gingiva, but rapidly extended to all the lingual and buccal mandibular gingiva during follow-up, leading to a diagnosis of gPVL. Two biopsies were performed, which concluded a verrucous hyperplasia and papilloma with a lichenoid part. The diagnosis of gPVL was made after a six-month follow-up based on clinical and anatomopathological factors. The gPVL transformed into a squamous cell carcinoma (SCC) after 18 months of follow-up. A surgical right mandibular bone excision with an autologous left fibula graft associated with radiotherapy was performed. Three years after the surgery, the patient remains under monitoring, with several gPVL and SCC recurrences treated. This case highlights that gPVL is a rare and aggressive form of PVL, with a high risk of fast malignant transformation. Knowledge about its aetiology, anatomic pathology, and biological markers is highly needed to speed up the diagnosis and develop specific follow-up and treatment.