title: Acetic acid treatment for wrinkle-free oral mucosal epithelia in paraffin section preparation.
abstract: For histopathological assessment of oral borderline malignancies, it is important to carefully detect subtle epithelial changes on fully stretched tissue sections. However, it is not generally easy to obtain wrinkle-free sections when using formalin-fixed paraffin-embedded oral mucosal samples. Since acetic acid treatment is already utilized for large brain tissue sections, we examined whether that treatment was also effective for oral mucosal tissues containing normal to malignant epithelial lesions. Paraffin sections were floated in various concentrations of acetic acid for 10 min after stretching in water for 1 min, then wrinkle formations were examined using hematoxylin and eosin staining, as well as for staining intensity with keratin immunohistochemistry. Wrinkles were formed in both epithelial and connective tissue zones of sections treated with less than a 40-mM (0.25%) concentration of acetic acid. In contrast, treatments with concentrations at 80 mM (0.5%) and higher resulted in cracking between the epithelial layer and lamina propria, as well as poor immunohistochemical results for keratins 13 and 17, even though the wrinkles completely disappeared. These results indicate that 40 mM is the optimal concentration of acetic acid solution to prevent wrinkles in the epithelial layer while maintaining the immunohistochemical qualities of oral mucosa tissue sections, especially those containing borderline malignant epithelial lesions.
authors.affiliation: Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan.
authors.forename: Md Shahidul
authors.initials: MS
authors.lastname: Ahsan
authors.forename: Satoshi
authors.initials: S
authors.lastname: Maruyama
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.forename: Kamal
authors.initials: K
authors.lastname: Al-Eryani
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Mayumi
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tsuneki
authors.forename: Takashi
authors.initials: T
authors.lastname: Saku
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D014408:Biomarkers, Tumor; D019343:Citric Acid / Q000378:metabolism*; D003238:Connective Tissue / Q000502:physiology; D004848:Epithelium / Q000502:physiology; D006801:Humans; D053535:Keratin-13 / Q000737:chemistry; D053537:Keratin-17 / Q000737:chemistry; D009061:Mouth Mucosa / Q000502:physiology*; D009062:Mouth Neoplasms / Q000175:diagnosis*; D016612:Paraffin Embedding / Q000379:methods*; D013048:Specimen Handling / Q000379:methods; D014059:Tongue / Q000502:physiology
chemical_list: D014408:Biomarkers, Tumor; C507426:KRT13 protein, human; D053535:Keratin-13; D053537:Keratin-17; D019343:Citric Acid; D019342:Acetic Acid