PP011: Brush versus scalpel: Consensus agreement on orcellex brush cytology versus incisional biopsy

Abstract

We have previously demonstrated the efficacy of brush cytology and liquid based cytology as a diagnostic adjunct in oral precancer management. The purpose of this study was to compare brush biopsy cytology with laser excision definitive histopathology. Histopathology following excision biopsy is the gold standard for diagnosis of oral dysplasia. Renewed interest in brush cytology however has demonstrated that microengineered brushes can demonstrate cellular changes before they are detected on excision biopsy, the implication being that cytology may be more than a useful adjunct to direct biopsies. It may be a useful prognostic test in itself. Following informed consent, patients with new red or white patches attending the oral dysplasia clinic were invited to participate in the study. All patients underwent brush cytology followed incision and where appropriate, laser excision biopsy. Consensus agreement was obtained by oral pathologists and cytologists working to agreed WHO criteria. 156 patients were recruited into the study. On cytology, normal ( n = 25); atypia ( n = 10); Candida ( n = 13); hyperkeratosis ( n = 53); mild dyskaryosis ( n = 15); moderate dyskaryosis ( n = 12); severe dyskaryosis ( n = 21) CIS ( n = 6); SCC ( n = 2). Excision biopsy however demonstrated hyperkeratosis with lichenoid inflammation ( n = 37), Hyperkeratosis alone ( n = 41), Candida ( n = 3); mild dysplasia ( n = 25); moderate dysplasia ( n = 14), proliferative verrucous leukoplakia ( n = 16); severe dysplasia ( n = 18); SCC ( n = 2). Mismatches in pathology versus cytology occurred in 55.6% cases. A random sample of 16 mismatches were further reviewed at a consensus meeting with 4 reporters and 11 mismatches were found here and 5 matches. In four cases, severe dyskaryosis with high Ki67 labelling indices were reported as hyperkeratosis with lichenoid by the panel of pathologists, and similarly in three cases, reported as mild dysplasia,or actinic keratosis. Cytology was unable to diagnose proliferative verrucous leukoplakia in four cases. Orcellex brush cytology particularly with or without KI67 labelling can demonstrate cellular changes that are not evident at the tissue level and upstage severity of premalignancy. It is a useful adjunct to oral precancer diagnosis.