We present the case of an 18-year-old girl who was sexually assaulted with transanal forearm penetration resulting in a fourth-degree perineal laceration. Fisting is an uncommon sexual practice consisting in the penetration of the vagina, anus, or both of them with fingers, hand (fist) or forearm.
Perineal lacerations are a relatively common finding in both consensual and nonconsensual fisting victims. Even though cases of fisting with first-, second-, and third-degree lacerations have been reported in literature, only one previous case of fourth-degree perineal laceration has been described in a woman, who died after anal fisting.
The clinical and morphological findings related to this sexual practice have been presented. No previous reports concerning nonfatal cases of fourth-degree perineal laceration, due to anal fisting, exists in literature. We report a case in which the forensic evaluation and the identification of the sexual assault were delayed because of both the atypical and uncommon pattern of injury and the unconsciousness of the patient. The information gathered thanks to this article would support forensic pathologists and sexual assault forensic examiners in recognizing doubtful cases, and this is particularly important when the suspect of sexual assault arise.