Official Publication of the National Center for Trauma Research Trauma Monthly 2251-7464 24 6 2019 11 01 Post-traumatic Intradiploic Leptomeningeal Cyst in Adult: A Case Report and Mini-Review of Literature 13 17 104268 10.30491/tm.2019.104268 EN Hossein Ghalaenovi Assistant professor of Neurosurgery, Iran University of Medical Sciences, Tehran, Iran Nourallah Eshraghi MD, Department of Neurosurgery, Qom University of Medical Sciences, Qom, Iran Arash Fattahi Assistant professor of Neurosurgery, Iran University of Medical Sciences, Tehran, Iran 0000-0002-1874-6527 Mohsen Benam Resident of Neurosurgery, Iran University of Medical Sciences, Tehran, Iran Journal Article 2019 07 18 Post-traumatic intradiploic leptomeningeal cyst (IDPTLC) manifests as an internal table disruption of the skull concomitant with a dural defect and intact external table after a previous skull fracture. It is very rare, especially in adults. We present a 30-year-old male with right occipital IDPTLC treated with duraplasty with allograft and cranioplasty with autograft ribs. Seventeen cases of IDPTLC in adulthood since 1978 were found in the literature; to the best of our knowledge, ours is the eighteenth case. Considering the possible etiology at the time of the first trauma, torn dura matter was not healed and retracted overtime. Also due to intracranial CSF pulsation, the disrupted inner table was widened and continuous force on the diploe caused a thinned swollen external table. We recommended performing overlying cranioplasty with autologous bone (rib or normal external table) with the edge of the duraplasty and the cranioplasty placed at different sites. https://www.traumamon.com/article_104268_ad0022c8f866ab209736074961ca2358.pdf