Idiopathic parietal bone thinning mimicking a bone lesion.

Idiopathic focal unilateral skull thinning is a rare finding. An explanation, such as trauma or disease, can often be found. However, in some cases, no explanation is forthcoming, and thus, we must look further into their history for a possible cause. The case of a nine-year-old boy with a crescent-shaped unilateral parietal bone thinning and a history of ventouse-assisted birth is presented. The lesion matches a ventouse's typical location, shape, and size. Thus, with the support of one other reported similar case, we hypothesise this may be the origin. We present the case of a crescent-shaped lesion matching the imprint of a ventouse in a child with a concordant history. This finding is put in the context of similar reports in the literature, and we believe that this report provides further evidence of this obscure phenomenon.

Funding: None declared.