Protruding into the brain’s dural sinuses, they allow for CSF resorption.
AGs are frequently found in parasagittal areas, along the superior sagittal and transverse sinuses, near the confluence of a cortical vein into the sinus.
On plain X-rays, IECs may present as rounded or lobulated lytic areas with smooth and sclerotic margins. Axial CT images with soft tissues (a) and bone (b) windows show an occipital hypodense osteolytic lesion with smooth margins and greater involvement of the inner table, extensively demineralised MR images show the presence of a mildly T1-hyperintense lesion, with iso-/hyperintensity on both T2-weighted and FLAIR images, restricted diffusion on diffusion-weighted imaging (DWI) and no contrast enhancement  (Fig. As a consequence, the patient presented with intracranial hypertension symptoms DCs are lined by stratified squamous epithelium but, unlike ECs, contain epidermal appendages, such as hair follicles, sweat glands and sebaceous glands.
At CT scans, non-enhancing hypodense focal lesions are their typical presentation, with associated sharply demarcated bony defects and calcifications, and the inner table generally more affected than the outer (Fig. These lesions, frequently occurring in childhood, with the highest incidence during the first or second decades of life, show a slow growth and tend to develop on the midline along the course of suture lines, near the anterior fontanelle [9, 10].
However, larger lesions have been reported, presenting with signs of intracranial hypertension and focal neurological signs. 3, the lesion appears slightly inhomogeneous, mostly hyperintense on T2w (a) and hypointense on T1w (b) images, without contrast enhancement (c), showing diffusion restriction on b 1000 diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) map (d, e).
IECs are benign, with infrequent malignant transformation, which may occur especially in cases of recurrence due to incomplete resection. It causes compression on the confluence of sinuses (sagittal contrast-enhanced T1w image, f).
It is also more accurate than CT in the assessment of intra- and extracranial extension.
In this review article, we will discuss pseudolesions (e.g.
Their appearance ranges from simple localised cysts to complex lesions, with dermal sinus and possible intracranial extension .
Histological differences with IECs may reflect in different imaging findings .