METHODS: Detailed, retrospective clinico-pathological analysis of potentially malignant lesions undergoing malignant transformation, from a 590 patient cohort treated by interventional laser surgery and followed for a mean of 7.3 years, was undertaken. Clinical outcome was documented at study census date (31 December 2014).
RESULTS: A total of 99 patients (16.8%) developed cancer: 71 (12%) seen "unexpectedly" upon excision and 28 (4.8%) progressing to malignancy at a median of 87.3 months post-surgery. Thirty "unexpected" excisions were micro-invasive (42.3%) arising primarily in severely dysplastic precursors (75%) at ventro-lateral tongue and floor of mouth sites (54.5%); 1 patient (1.4%) had a cancer-related death, whilst 58 (81.7%) were disease free. A total of 19 of 28 "progressive" cancers (67.9%) arose at new sites, with erythroleukoplakia a significant predictor of malignancy (P = .0019). Nine (32.1%) developed at the same precursor site, with 6 (77.7%) on the ventro-lateral tongue and floor of mouth. Three (10.7%) were micro-invasive, 9 patients (32.1%) died from metastatic disease and 12 (42.9%) were disease free (P < .001).
CONCLUSION: Squamous carcinoma may arise at the site of a precursor lesion as transformation or new-site development via field cancerisation. Whilst interventional surgery facilitates early diagnosis and treatment of occult disease, thus reducing risk from same-site transformation, new-site cancer is a significant long-term risk for patients with potentially malignant disorder.
MATERIALS AND METHODS: In a retrospective multicentre study, using pathology archives, 188 verruco-papillary lesions were retrieved from pathology archives. A proforma listing histopathological criteria for OVH based on published guidelines (Annals of Dentistry, University of Malaya, 2013) was used. Patients' demographic and clinical data were transcribed from patient charts. The Pearson chi-square test was used to determine associations between clinical and histopathological features.
RESULTS: Of 188 oral verruco-papillary lesions that were evaluated, based on microscopic features the cases were reclassified as OVH (57), verrucous carcinoma (VC) (84), oral squamous cell carcinoma (16), and other verruco-papillary lesions (31). Both OVH (70%) and VC (60%) showed male predominance and commonly affected buccal mucosa (OVH 74% and VC 57%). Absence of downward growth of the hyperplastic epithelium into lamina propria when compared with the level of the basement membrane of the adjacent normal epithelium was a distinct feature in OVH. Keratin plugging, epithelial dysplasia and subepithelial lymphocytic infiltration were found to be significantly different (P