acetowhite

Acetowhite refers to a transient whitening of cervical epithelium observed during colposcopic examination after the application of dilute acetic acid, typically 3% to 5%. The whitening reaction is used to identify areas that may warrant closer inspection for potential cervical neoplasia or HPV-associated changes.

Mechanism and appearance: Acetic acid causes a temporary coagulation of proteins in cells with higher nuclear density, such as dysplastic or HPV-infected cells. These areas turn white relative to surrounding normal tissue, producing what clinicians describe as acetowhite lesions. The reaction is immediate and usually diminishes within minutes after the acid is washed away.

Clinical use: During colposcopy, acetic acid is applied to the cervix to map acetowhite areas. These acetowhite zones guide targeted biopsies to obtain histologic confirmation of disease. The presence, size, and borders of acetowhite changes help assess the likelihood of cervical intraepithelial neoplasia and other pathology.

Interpretation and limitations: Acetowhite changes are not specific for high-grade disease and can occur with benign inflammatory or physiological cervical changes. False negatives can occur, and some high-grade lesions may not produce prominent whitening. Therefore, acetowhite findings are integrated with cytology, HPV testing, and histopathology for diagnosis and management decisions.

See also: Colposcopy, Cervical intraepithelial neoplasia, Human papillomavirus.