Giant non-traumatic and non-iatrogenic cranial vault defects are poorly studied due to their rarity. Therefore, diagnosis and analysis of their causes are difficult. In available literature, we found only 4 cases of giant pericranial sinus accompanied by extensive cranial vault defects. Authors want to present a rare and difficult diagnostic case of cranial vault lesion with non-traumatic and non-iatrogenic extensive bone defect, as well as to propose treatment of this pathology. The patient presented with complaints of a «growing» parietal-occipital cranial vault defect in November 2022. This defect occurred in childhood. A comprehensive examination including CT angiography of cerebral vessels was followed by surgical treatment (bone resection along skull defect edge with biopsy (aponeurosis, periosteum, bone) and subsequent closure with titanium plate). Postoperative period was uneventful. CT of the skull and brain, including angiography and sinusography, were performed. The follow-up period was more than 10 months with favorable outcome. Considering anamnesis, clinical and additional diagnostic data, we established giant dominant-type true pericranial sinus.

Andrey Semenov has been studying at Irkutsk State Medical University (Russia) since 2019. He is a student of the Faculty of Medicine. He has 4 publications, one of which was published by the journal "Burdenko’s Journal of Neurosurgery", Moscow, Russia.