This 4-month-old boy arrived unresponsive at the emergency room. The mother was at work when her partner called to tell her the child was unresponsive. The child was taken care of by a nanny occasionally, but she had not been in contact with the child for at least 3 or 4 days. A CT scan of the head showed intense cerebral oedema. Chest x-ray showed multiple rib fractures in various stages of healing. The child died from the head injury. External examination of the scrotum at autopsy showed the injury presented in Image 68a. https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429170423/236ca68c-f283-4df8-88b2-3b8ff49bccc9/content/fig68a.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>

What is shown in Image 68a?

What procedure is important for evaluation of the injury?

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This is a contusion of the scrotum. In a 4-month-old child, this is an inflicted injury. The bruise has multiple hues, from yellow to red-purple. One of the more common explanations for these bruises is that someone else other than the immediate caretaker caused it, and that was the case here – blame was placed on the nanny. Because of the multiple colours present on the skin, it was thought that the injury was inflicted multiple times. However it is not possible to date bruises accurately. 1 , 2

Extensive dissection of the skin by the forensic pathologist is essential for a complete evaluation of all cutaneous injuries. In these cases, multiple incisions on the back, groin and extremities are necessary with extensive separation of the skin to adequately evaluate subcutaneous haemorrhage, the main sign of an impact site. Even in light-skinned children, not all injuries may be apparent unless this is done. Image 68b shows that there is recent, red-purple haemorrhage of the subcutaneous tissue of the scrotum, which excludes the nanny as the perpetrator of this injury since haemorrhage with this appearance indicates the injury is not more than a day or so old. Also seen is the testicle with the epididymis.