Abrasive cytohistology of squamous epithelial lesions
Objective: To describe a method to retrieve cellular and tissue elements of oral squamous epithelium obtained by abrasive methods and to conduct investigations by cytohistology. Method: We developed a special gelatine pocket suitable for paraffin embedding of sparse material obtained from brush biopsies (BBs) This was subjected to combined evaluation of a cytological (smear) and histological examination of the 'tissue sections' referred as cytohistology. Four diagnostic categories were applied for evaluation. Other special diagnostic methods were also applied in addition to recording dysplasia. Results: A total of 51, 755 BBs from suspicious lesions of the oral mucosa (mostly oral potentially malignant disorders OPMD) were evaluated for the presence of carcinoma or dysplasia; in all, 1.7% were positive, 78.2% were negative for any epithelial atypia, 16.8% atypical and 3.3% inadequate. All BBs also had cytohistological evaluation. A 'positive' diagnosis by cytohistology was a reliable indicator of dysplasia or carcinoma, requiring further incisional/excisional biopsy. In the 'atypical' category, a variety of lesions were found, about half being dysplasia or carcinoma. This category challenges the clinician for further clinical, therapeutic and/or excisional examination. In 'negative' cases with persistence of the lesion, a re examination in 1 year sequence is recommended. Conclusion: Cytohistology of material derived by abrasive methods allows earlier detection of dysplasia/carcinoma. A number of additional oncological and non oncological findings make this method a valuable non invasive diagnostic procedure for oral mucosal lesions.