Operative management of a nail wound projectile to the skull base with unusual trajectory: illustrative case.

backgroundPenetrating cranial trauma through the orbit presents significant diagnostic and surgical challenges, especially when external signs are minimal. Blast injuries may drive foreign bodies (FBs) along unpredictable trajectories, risking vascular injury, intracranial hematoma, CSF leak, and infection. Prompt imaging and early multidisciplinary intervention are critical for avoiding complications and sequelae. OBSERVATIONS: A 24-year-old sustained a blast injury from mortar fire, resulting in a 10-cm nail penetrating his skull base. Remarkably, he walked 7 km to a medical facility, presenting with a 2.5-cm submandibular wound. CT revealed the nail had traversed the superior orbital fissure into both the anterior and middle cranial fossae, causing a right subdural hematoma, complete ophthalmoplegia, amaurosis, and sylvian venous injury. Angiography ruled out any arterial injury. The patient underwent a wide frontotemporal craniotomy for decompression and safe mobilization of the FB. Dural and skull base reconstruction was performed at two sites using autologous muscle and a vascularized pericranial flap. LESSONS: Penetrating orbital wounds can obscure life-threatening intracranial trauma and may present with different trajectories involving multiple craniofacial compartments. Thin-cut CT imaging and early cerebral angiography are essential for diagnosis, and multidisciplinary planning is critical for safe and effective intervention for FB removal and reconstruction. https://thejns.org/doi/10.3171/CASE25577.