Head Trauma in Pycnodysostosis: An Imagiological Challenge.

A 10-year-old girl with a known diagnosis of pycnodysostosis presented to the emergency department after a traumatic head injury. Physical examination revealed a fluctuant triangular deformity in the parieto-occipital region, raising suspicion of a skull fracture. Computed tomography (CT) demonstrated heterogeneous bone density with radiated sclerosis of the parietal bones, consistent with her underlying condition, and a partial discontinuity of the lambdoid suture without signs of an acute fracture. A conservative, watchful approach was undertaken with complete recovery. This case highlights the diagnostic challenges posed by pycnodysostosis in differentiating acute trauma from chronic skeletal abnormalities.