Stathmin is a highly sensitive and specific biomarker for vulvar high-grade squamous intraepithelial lesions.

Aims: Differentiating between human papilloma virus-dependent vulvar low-grade and high-grade squamous intraepithelial lesions (LSILs and HSILs) remains difficult in selected cases. Stathmin, a protein involved in cell cycle progression, might be a useful additional marker for this differentiation. The aim of this study was to investigate the additional diagnostic value of stathmin expression in vulvar intraepithelial neoplastic (VIN) lesions.

Methods: Immunohistochemical analysis was used to evaluate stathmin, P16 and Ki67 expression in 91 samples, including LSILs (n=16), HSILs (n=50), differentiated VIN (dVIN; n=10), lichen sclerosis (LS; n=10) and normal vulvar tissue (n=5).

Results: Stathmin was expressed in more than one-third of the epithelium in all HSILs and in 20% of LSILs. P16 and Ki67 were expressed in more than one-third of the epithelium in 94% of HSILs and in 13% and 40% of LSILs, respectively. Stathmin was expressed in more than one-third of the epithelium in 10% of the dVIN and in none of the LS or normal lesions. P16 and Ki67 expression was not present in more than one-third of the epithelium in any of these lesions. The sensitivity of stathmin for differentiating between LSILs and HSILs was 100% compared with a sensitivity of 94% for both p16 and Ki67. The specificity of stathmin, p16 and Ki67 was 80%, 87% and 60%, respectively.

Conclusions: Stathmin is a highly sensitive and specific biomarker for the diagnosis of vulvar HSIL. In addition to the more commonly used immunohistochemical markers p16 and Ki67, stathmin can be a useful diagnostic tool for identifying HSILs, especially in cases in which differentiating between LSIL and HSIL is difficult.