Intraparenchymal or intradiploic epidermoid cysts are very rare. Most of these cysts, when present, tend to involve the frontal and temporal lobes, and occasionally, the pineal gland or the brain stem. Here, we report a 45-year-old female, who presented with localized occipital headache and a tender occipital swelling, gradually increasing in size. She was hemodynamically and neurologically stable and did not have any focal neurological deficits. Whole skull and brain imaging revealed a well-demarcated expansile lytic lesion in the right occipital bone, which was hypointense on T1-weighted and hyperintense on both T2-weighted imaging and diffusion-weighted imaging without any contrast enhancement. The patient underwent a right occipital craniotomy and total excision of the intradiploic space occupying lesion. Histopathological examination confirmed the lytic bone lesion over occipital bone as intradiploic epidermoid cyst.

The findings of this study support that cancer incidence is increasing in India and more epidemiological studies are needed.

Intracranial meningiomas without dural attachment are rare and posterior cranial fossa meningiomas without dural attachment are rarer. Such meningiomas are thought to arise from arachnoid cap cells in pial membrane, tela choroidea, or choroid plexus. MRI is the best imaging modality for the diagnosis of meningiomas and typically shows an enhancing, dural based, extra-axial soft tissue mass with a characteristic dural tail. Meningioma without dural attachment should be suspected if the MRI shows a space-occupying lesion having features of a meningioma but without a dural base and dural tail. We report a case of meningioma in the lateral cerebellomedullary cistern without dural attachment.

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